ATA5746C-PXQW [MICROCHIP]

Telecom Circuit, 1-Func;
ATA5746C-PXQW
型号: ATA5746C-PXQW
厂家: MICROCHIP    MICROCHIP
描述:

Telecom Circuit, 1-Func

ATM 异步传输模式 电信 电信集成电路
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ATA5745C/ATA5746C  
UHF ASK/FSK Receiver  
DATASHEET  
Features  
Transparent RF receiver ICs for 315MHz (Atmel® ATA5746C) and 433.92MHz  
(Atmel ATA5745C) with high receiving sensitivity  
Fully integrated PLL with low phase noise VCO, PLL, and loop filter  
High FSK/ASK sensitivity:  
–105dBm (Atmel ATA5746C, FSK, 9.6Kbits/s, Manchester, BER 10-3)  
–114dBm (Atmel ATA5746C, ASK, 2.4Kbits/s, Manchester, BER 10-3)  
–104dBm (Atmel ATA5745C, FSK, 9.6Kbits/s, Manchester, BER 10-3)  
–113dBm (Atmel ATA5745C, ASK, 2.4Kbits/s, Manchester, BER 10-3)  
Supply current: 6.5mA in Active Mode (3V, 25°C, ASK Mode)  
Data rate: 1Kbit/s to 10Kbits/s Manchester ASK, 1Kbit/s to 20Kbits/s Manchester  
FSK with four programmable bit rate ranges  
Switching between modulation types ASK/FSK and different data rates possible in  
1ms typically, without hardware modification on board to allow different  
modulation schemes for RKE, TPMS  
Low standby current: 50µA at 3V, 25°C  
ASK/FSK receiver uses a Low-IF architecture with high selectivity, blocking, and  
Low intermodulation (typical 3-dB blocking 68.0dBC at ±3MHz/74.0dBC at  
±20.0MHz, system I1dBCP = –31dBm/system IIP3 = –24dBm)  
Telegram pause up to 52ms supported in ASK Mode  
Wide bandwidth AGC to handle large out-of-band blockers above the system  
I1dBCP  
440-kHz IF frequency with 30-dB image rejection and 420-kHz IF bandwidth to  
support PLL transmitters with standard crystals or SAW-based transmitters  
RSSI (Received Signal Strength Indicator) with output signal dynamic range of  
65dB  
Low in-band sensitivity change of typically ±2.0dB within ±160-kHz center  
frequency change in the complete temperature and supply voltage range  
Sophisticated threshold control and quasi-peak detector circuit in the data slicer  
Fast and stable XTO start-up circuit (> –1.4kΩ worst-case start impedance)  
Clock generation for microcontroller  
9249B-RKE-08/12  
ESD protection at all pins (±4kV HBM, ±200V MM, ±500V FCDM)  
Dual supply voltage range: 2.7V to 3.3V or 4.5V to 5.5V  
Temperature range: –40°C to +105°C  
Small 5mm × 5mm QFN24 package  
Applications  
Automotive keyless entry and tire pressure monitoring systems  
Alarm, telemetering and energy metering systems  
Benefits  
Supports header and blanking periods of protocols common in RKE and TPM systems (up to 52ms in ASK Mode)  
All RF relevant functions are integrated. The single-ended RF input is suited for easy adaptation to λ / 4 or printed-loop  
antennas  
Allows a low-cost application with only 8 passive components  
Suitable for use in a receiver for joint RKE and TPMS  
Optimal bandwidth maximizes sensitivity while maintaining SAW transmitter compatibility  
Clock output provides an external microcontroller crystal-precision time reference  
Well suited for use with Atmel® PLL transmitter ATA5756/ATA5757  
2
ATA5745C/ATA5746C [DATASHEET]  
9249B–RKE–08/12  
1.  
General Description  
The Atmel® ATA5745C/ATA5746C is a UHF ASK/FSK transparent receiver IC with low power consumption supplied in a  
small QFN24 package (body 5mm × 5mm, pitch 0.65mm). Atmel ATA5745C is used in the 433MHz to 435MHz band of  
operation, and Atmel ATA5746C in 313MHz to 317MHz. The IC combines the functionality of remote keyless entry (RKE -  
typically low bit rate ASK) and tire pressure monitoring (TPM - typically high bit rate FSK) into one receiver under the control  
of an external microcontroller such as an Atmel ATmega48 (AVR®).  
For improved image rejection and selectivity, the IF frequency is fixed to 440kHz. The IF block uses an 8th-order band pass  
yielding a receive bandwidth of 420kHz. This enables the use of the receiver in both SAW- and PLL-based transmitter  
systems utilizing various types of data-bit encoding such as pulse width modulation, Manchester modulation, variable pulse  
modulation, pulse position modulation, and NRZ. Prevailing encryption protocols such as Keeloq® are easily supported due  
to the receiver’s ability to hold the current data slicer threshold for up to 52ms when incoming RF telegrams contain a  
blanking interval. This feature eliminates erroneous noise from appearing on the demodulated data output pin, and simplifies  
software decoding algorithms. The decoding of the data stream must be carried out by a connected microcontroller device.  
Because of the highly integrated design, the only required RF components are for the purpose of receiver antenna matching.  
Atmel ATA5745C and Atmel ATA5746C support Manchester bit rates of 1Kbit/s to 10Kbits/s in ASK and 1Kbit/s to 20Kbits/s  
in FSK mode. The four discrete bit rate passbands are selectable and cover 1.0Kbit/s to 2.5Kbits/s, 2.0Kbits/s to 5.0Kbits/s,  
4.0Kbits/s to 10.0Kbits/s, and 8.0Kbits/s to 10.0Kbits/s or 20.0Kbits/s (for ASK or FSK, respectively). The receiver contains  
an RSSI output to provide an indication of received signal strength and a SENSE input to allow the customer to select a  
threshold below which the DATA signal is gated off. ASK/FSK and bit rate ranges are selected by the connected  
microcontroller device via pins ASK_NFSK, BR0, and BR1.  
Figure 1-1. System Block Diagram  
ATA5745C/ATA5746C  
Digital Control  
Logic  
Power  
Supply  
Antenna  
RF Receiver  
Microcontroller  
4 ... 8  
(LNA, Mixer,  
VCO, PLL,  
IF Filter,  
Microcontroller  
Interface  
RSSI Amp.,  
Demodulator)  
XTO  
ATA5745C/ATA5746C [DATASHEET]  
3
9249B–RKE–08/12  
Figure 1-2. Pinning QFN24  
24 23 22 21 20 19  
18  
TEST2  
TEST1  
CLK_OUT  
1
2
3
4
5
6
TEST3  
RSSI  
SENSE_CTRL  
SENSE  
LNA_IN  
17  
16  
15  
14  
13  
CLK_OUT_CTRL1  
CLK_OUT_CTRL0  
ENABLE  
LNA_GND  
7
8
9 10 11 12  
Table 1-1. Pin Description  
Pin  
1
Symbol  
Function  
TEST2  
TEST1  
Test pin, during operation at GND  
Test pin, during operation at GND  
Output to clock a connected microcontroller  
Input to control CLK_OUT (MSB)  
Input to control CLK_OUT (LSB)  
Input to enable the XTO  
2
3
CLK_OUT  
CLK_OUT_CTRL1  
CLK_OUT_CTRL0  
ENABLE  
XTAL2  
4
5
6
7
Reference crystal  
8
XTAL1  
Reference crystal  
9
DVCC  
Digital voltage supply blocking  
Power supply input for voltage range 4.5V to 5.5V  
Power supply input for voltage range 2.7V to 3.3V  
Ground  
10  
11  
12  
13  
14  
15  
VS5V  
VS3V_AVCC  
GND  
LNA_GND  
LNA_IN  
RF ground  
RF input  
SENSE  
Sensitivity control resistor  
Sensitivity selection  
Low: Normal sensitivity, High: Reduced sensitivity  
16  
SENSE_CTRL  
17  
18  
19  
20  
21  
RSSI  
TEST3  
RX  
Output of the RSSI amplifier  
Test pin, during operation at GND  
Input to activate the receiver  
Bit rate selection, LSB  
BR0  
BR1  
Bit rate selection, MSB  
FSK/ASK selection  
Low: FSK, High: ASK  
22  
ASK_NFSK  
23  
24  
CDEM  
DATA_OUT  
GND  
Capacitor to adjust the lower cut-off frequency data filter  
Data output  
Ground/backplane (exposed die pad)  
4
ATA5745C/ATA5746C [DATASHEET]  
9249B–RKE–08/12  
Figure 1-3. Block Diagram  
ASK  
FSK  
ASK/FSK  
Demo-  
dulator  
VS3V_AVCC  
VS5V  
Power  
Supply  
CDEM  
ASK/FSK  
Control  
ASK_NFSK  
IF Amp  
SENSE  
Data  
DATA_OUT  
BR0  
BR1  
Slicer  
SENSE_CTRL  
IF Filter  
LPF  
GND  
Standby  
Logic Control  
RX  
CLK_OUT_CTRL1  
CLK_OUT_CTRL0  
CLK_OUT  
XTO  
DVCC  
Div. by 3, 6, 12  
IF Amp  
LPF  
RSSI  
PLL  
XTO  
ENABLE  
(/24, /32)  
TEST1  
TEST2  
TEST3  
LNA_IN  
LNA  
VCO  
LNA_GND  
XTAL2  
XTAL1  
ATA5745C/ATA5746C [DATASHEET]  
5
9249B–RKE–08/12  
 
2.  
RF Receiver  
As seen in Figure 1-3 on page 5, the RF receiver consists of a low-noise amplifier (LNA), a local oscillator, and the signal  
processing part with mixer, IF filter, IF amplifier with analog RSSI, FSK/ASK demodulator, data filter, and data slicer.  
In receive mode, the LNA pre-amplifies the received signal which is converted down to a 440-kHz intermediate frequency  
(IF), then filtered and amplified before it is fed into an FSK/ASK demodulator, data filter, and data slicer. The received signal  
strength indicator (RSSI) signal is available at the pin RSSI.  
2.1  
Low-IF Receiver  
The receive path consists of a fully integrated low-IF receiver. It fulfills the sensitivity, blocking, selectivity, supply voltage,  
and supply current specification needed to design an automotive integrated receiver for RKE and TPM systems. A benefit of  
the integrated receive filter is that no external components needed.  
At 315MHz, the Atmel® ATA5745C receiver (433.92MHz for the Atmel ATA5746C receiver) has a typical system noise figure  
of 6.0dB (7.0dB), a system I1dBCP of –31dBm (–30dBm), and a system IIP3 of –24dBm (–23dBm). The signal path is linear  
for out-of-band disturbers up to the I1dBCP and hence there is no AGC or switching of the LNA needed, and a better  
blocking performance is achieved. This receiver uses an IF (intermediate frequency) of 440kHz, the typical image rejection is  
30dB and the typical 3-dB IF filter bandwidth is 420kHz (fIF = 440kHz ± 210kHz, flo_IF = 230kHz and fhi_IF = 650kHz). The  
demodulator needs a signal-to-noise ratio of 8.5dB for 10Kbits/s Manchester with ±38kHz frequency deviation in FSK mode,  
thus, the resulting sensitivity at 315MHz (433.92MHz) is typically –105dBm (–104dBm).  
Due to the low phase noise and spurs of the synthesizer together with the 8th-order integrated IF filter, the receiver has a  
better selectivity and blocking performance than more complex double superhet receivers, without using external  
components and without numerous spurious receiving frequencies.  
A low-IF architecture is also less sensitive to second-order intermodulation (IIP2) than direct conversion receivers where  
every pulse or amplitude modulated signal (especially the signals from TDMA systems like GSM) demodulates to the  
receiving signal band at second-order non-linearities.  
2.2  
Input Matching at LNA_IN  
The measured input impedances as well as the values of a parallel equivalent circuit of these impedances can be seen in  
Table 2-1. The highest sensitivity is achieved with power matching of these impedances to the source impedance.  
Table 2-1. Measured Input Impedances of the LNA_IN Pin  
fRF [MHz]  
315  
ZIn(RF_IN) [Ω]  
(72.4 – j298)  
(55 – j216)  
RIn_p//CIn_p [pF]  
1300Ω//1.60  
900Ω//1.60  
433.92  
The matching of the LNA input to 50Ω is done using the circuit shown in Figure 2-1 and the values of the matching elements  
given in Table 2-2. The reflection coefficients were always –10dB. Note that value changes of C1 and L1 may be  
necessary to compensate individual board layout parasitics. The measured typical FSK and ASK Manchester-code  
sensitivities with a bit error rate (BER) of 10–3 are shown in Table 2-3 and Table 2-4 on page 7. These measurements were  
done with wire-wound inductors having quality factors reported in Table 2-2, resulting in estimated matching losses of 0.8dB  
at 315MHz and 433.92MHz. These losses can be estimated when calculating the parallel equivalent resistance of the  
inductor with Rloss = 2 × π × f × L × QL and the matching loss with 10 log(1+RIn_p / Rloss).  
Figure 2-1. Input Matching to 50Ω  
ATA5745C/ATA5746C  
RFIN  
C1  
14  
LNA_IN  
L1  
6
ATA5745C/ATA5746C [DATASHEET]  
9249B–RKE–08/12  
 
 
Table 2-2. Input Matching to 50Ω  
fRF [MHz]  
315  
C1 [pF]  
2.2  
L1 [nH]  
68  
QL1  
20  
433.92  
2.2  
36  
15  
Table 2-3. Measured Typical Sensitivity FSK, ±38 kHz, Manchester, BER = 10–3  
BR_Range_0  
1.0Kbit/s  
BR_Range_0  
2.5Kbits/s  
BR_Range_1  
5Kbits/s  
BR_Range_2  
10Kbits/s  
BR_Range_3  
10Kbits/s  
BR_Range_3  
RF Frequency  
315MHz  
20Kbits/s  
–104dBm  
–103dBm  
–108dBm  
–107dBm  
–108dBm  
–107dBm  
–107dBm  
–106dBm  
–105dBm  
–104dBm  
–104dBm  
–103dBm  
433.92MHz  
Table 2-4. Measured Typical Sensitivity 100% ASK, Manchester, BER = 10–3  
BR_Range_0  
1.0Kbit/s  
BR_Range_0  
2.5Kbits/s  
BR_Range_1  
5Kbits/s  
BR_Range_2  
10Kbits/s  
BR_Range_3  
RF Frequency  
315MHz  
10Kbits/s  
–109dBm  
–108dBm  
–114dBm  
–113dBm  
–114dBm  
–113dBm  
–113dBm  
–112dBm  
–111dBm  
–110dBm  
433.92MHz  
Conditions for the sensitivity measurement:  
The given sensitivity values are valid for Manchester-modulated signals. For the sensitivity measurement the distance from  
edge to edge must be evaluated. As can be seen in Figure 6-1 on page 22, in a Manchester-modulated data stream, the time  
segments TEE and 2 × TEE occur.  
To reach the specified sensitivity for the evaluation of TEE and 2 × TEE in the data stream, the following limits should be used  
(TEE min, TEE max, 2 × TEE min, 2 × TEE max).  
Table 2-5. Limits for Sensitivity Measurements  
Bit Rate  
1.0Kbit/s  
2.4Kbits/s  
5.0Kbits/s  
9.6Kbits/s  
TEE Min  
260µs  
110µs  
55µs  
TEE Typ  
500µs  
208µs  
100µs  
52µs  
TEE Max  
790µs  
310µs  
155µs  
78µs  
2 × TEE Min  
800µs  
2 × TEE Typ  
1000µs  
416µs  
2 × TEE Max  
1340µs  
525µs  
320µs  
160µs  
200µs  
260µs  
27µs  
81µs  
104µs  
131µs  
2.3  
Sensitivity Versus Supply Voltage, Temperature and Frequency Offset  
To calculate the behavior of a transmission system, it is important to know the reduction of the sensitivity due to several  
influences. The most important are frequency offset due to crystal oscillator (XTO) and crystal frequency (XTAL) errors,  
temperature and supply voltage dependency of the noise figure, and IF-filter bandwidth of the receiver. Figure 2-2 and  
Figure 2-3 on page 8 show the typical sensitivity at 315MHz, ASK, 2.4Kbits/s and 9.6Kbits/s, Manchester, Figure 2-4 and  
Figure 2-5 on page 9 show a typical sensitivity at 315MHz, FSK, 2.4Kbits/s and 9.6Kbits/s, ±38kHz, Manchester versus the  
frequency offset between transmitter and receiver at Tamb = –40°C, +25°C, and +105°C and supply voltage  
VS = VS3V_AVCC = VS5V = 2.7V, 3.0V and 3.3V.  
ATA5745C/ATA5746C [DATASHEET]  
7
9249B–RKE–08/12  
 
Figure 2-2. Measured Sensitivity (315MHz, ASK, 2.4Kbits/s, Manchester) Versus Frequency Offset  
Input Sensitivity (dBm) at BER < 1e-3, ATA5746C, ASK, 2.4Kbits/s (Manchester),  
BR = 0  
-118  
-117  
-116  
-115  
-114  
2.7V / -40°C  
-113  
-112  
-111  
-110  
-109  
-108  
-107  
-106  
-105  
-104  
-103  
3.0V / -40°C  
3.3V / -40°C  
2.7V / 27°C  
3.0V / 27°C  
3.3V / 27°C  
2.7V / 105°C  
3.0V / 105°C  
3.3V / 105°C  
-300  
-200  
-100  
0
100  
200  
300  
delta RF (kHz) at 315MHz  
Figure 2-3. Measured Sensitivity (315MHz, ASK, 9.6Kbits/s, Manchester) Versus Frequency Offset  
Input Sensitivity (dBm) at BER < 1e-3, ATA5746C, ASK, 9.6Kbits/s (Manchester),  
BR = 2  
-115  
-114  
-113  
-112  
-111  
-110  
2.7V / -40°C  
-109  
-108  
-107  
-106  
-105  
-104  
-103  
-102  
-101  
-100  
3.0V / -40°C  
3.3V / -40°C  
2.7V / 27°C  
3.0V / 27°C  
3.3V / 27°C  
2.7V / 105°C  
3.0V / 105°C  
3.3V / 105°C  
-300  
-200  
-100  
0
100  
200  
300  
delta RF (kHz) at 315MHz  
8
ATA5745C/ATA5746C [DATASHEET]  
9249B–RKE–08/12  
Figure 2-4. Measured Sensitivity (315MHz, FSK, 2.4Kbits/s, ±38kHz, Manchester) Versus Frequency Offset  
Input Sensitivity (dBm) at BER < 1e-3, ATA5746, FSK, 2.4Kbits/s  
(Manchester), BR0  
-112  
-111  
-110  
-109  
-108  
-107  
-106  
2.7V / -40°C  
3.0V / -40°C  
3.3V / -40°C  
2.7V / 27°C  
3.0V / 27°C  
3.3V / 27°C  
2.7V / 105°C  
3.0V / 105°C  
3.3V / 105°C  
-105  
-104  
-103  
-102  
-101  
-100  
-99  
-98  
-300  
-200  
-100  
0
100  
200  
300  
delta RF (kHz) at 315MHz  
Figure 2-5. Measured Sensitivity (315MHz, FSK, 9.6Kbits/s, ±38kHz, Manchester) Versus Frequency Offset  
Input Sensitivity (dBm) at BER < 1e-3, ATA5746C, FSK, 9.6Kbits/s (Manchester),  
BR = 2  
-110.00  
-109.00  
-108.00  
-107.00  
2.7V / -40°C  
-106.00  
-105.00  
-104.00  
-103.00  
-102.00  
-101.00  
-100.00  
-99.00  
-98.00  
-97.00  
-96.00  
3.0V / -40°C  
3.3V / -40°C  
2.7V / 27°C  
3.0V / 27°C  
3.3V / 27°C  
2.7V / 105°C  
3.0V / 105°C  
3.3V / 105°C  
-95.00  
-300  
-200  
-100  
0
100  
200  
300  
delta RF (kHz) at 315MHz  
ATA5745C/ATA5746C [DATASHEET]  
9
9249B–RKE–08/12  
As can be seen in Figure 2-5 on page 9, the supply voltage has almost no influence. The temperature has an influence of  
about ±1.0dB, and a frequency offset of ±160kHz also influences by about ±1dB. All these influences, combined with the  
sensitivity of a typical IC (–105dB), are then within a range of –103.0dBm and –107.0dBm over temperature, supply voltage,  
and frequency offset. The integrated IF filter has an additional production tolerance of ±10kHz, hence, a frequency offset  
between the receiver and the transmitter of ±160kHz can be accepted for XTAL and XTO tolerances.  
Note:  
For the demodulator used in the Atmel ATA5745C/ATA5746C, the tolerable frequency offset does not change  
with the data frequency. Hence, the value of ±160kHz is valid for 1Kbit/s to 10Kbits/s.  
This small sensitivity change over supply voltage, frequency offset, and temperature is very unusual in such a receiver. It is  
achieved by an internal, very fast, and automatic frequency correction in the FSK demodulator after the IF filter, which leads  
to a higher system margin. This frequency correction tracks the input frequency very quickly. If, however, the input frequency  
makes a larger step (for example, if the system changes between different communication partners), the receiver has to be  
restarted. This can be done by switching back to Standby mode and then again to Active mode (pin RX 1 −−> 0 1) or  
by generating a positive pulse on pin ASK_NFSK (0 1 0).  
2.4  
Frequency Accuracy of the Crystals in a Combined RKE and TPM System  
In a tire pressure measurement system working at 315MHz and using an Atmel® ATA5756 as transmitter and an Atmel  
ATA5746C is receiver, the higher frequency tolerances and the tolerance of the frequency deviation of the transmitter has to  
be considered.  
In the TPM transmitter, the crystal has a frequency error over temperature –40°C to 125°C, aging, and tolerance of ±80ppm  
(±25.2kHz at 315MHz). The tolerances of the XTO, the capacitors used for FSK modulation, and the stray capacitances  
cause an additional frequency error of ±30 ppm (±9.45kHz at 315MHz). The frequency deviation of such a transmitter varies  
between ±16kHz and ±24kHz, since a higher frequency deviation is equivalent to a frequency error this has to be considered  
as an additional  
±24kHz – ±19.5kHz = ±4.5kHz frequency tolerance (19.5kHz is constant). All tolerances added, these transmitters have a  
worst-case frequency offset of ±39.15kHz.  
For the receiver in the car, a tolerance of ±160kHz – ±39.15kHz = ±120.85kHz (±383.6ppm) remains. The needed frequency  
stability of the crystals over temperature and aging is ±383.6ppm – ±5ppm = ±378.6ppm. The aging of such a crystal is  
±10ppm, leaving a reasonable ±368.6 ppm for the temperature dependency of the crystal frequency in the car.  
Since the receiver in the car is able to receive these TPM transmitter signals with high frequency offsets, the component  
specification in the key can be largely relaxed.  
This system calculation is based on worst-case tolerances of all the components; this leads in practice to a system with  
margin.  
For a 433.92MHz TPM system using Atmel ATA5757 as transmitter and Atmel ATA5745C as receiver, the same calculation  
must be done, but since the RF frequency is higher, every ppm of crystal tolerances results in higher frequency offset and  
either the system must have lower tolerances or a lower margin at this frequency.  
2.5  
RX Supply Current Versus Temperature and Supply Voltage  
Table 2-7 shows the typical supply current of the receiver in Active mode versus supply voltage and temperature with VS =  
VS3V_AVCC = VS5V.  
Table 2-6. Measured Current in Active Mode ASK  
VS = VS3V_AVCC = VS5V  
Tamb = –40°C  
2.7V  
3.0V  
3.3V  
5.4mA  
6.4mA  
7.4mA  
5.5mA  
6.5mA  
7.5mA  
5.6mA  
6.6mA  
7.6mA  
Tamb = 25°C  
Tamb = 105°C  
Table 2-7. Measured Current in Active Mode FSK  
VS = VS3V_AVCC = VS5V  
Tamb = –40°C  
2.7V  
3.0V  
3.3V  
5.6mA  
6.6mA  
7.6mA  
5.7mA  
6.7mA  
7.7mA  
5.8mA  
6.8mA  
7.8mA  
Tamb = 25°C  
Tamb = 105°C  
10  
ATA5745C/ATA5746C [DATASHEET]  
9249B–RKE–08/12  
 
2.6  
Blocking, Selectivity  
As can be seen in Figure 2-6 on page 11, and Figure 2-7 and Figure 2-8 on page 12, the receiver can receive signals 3dB  
higher than the sensitivity level in the presence of large blockers of –34.5dBm or –28dBm with small frequency offsets of  
±3MHz or ±20MHz.  
Figure 2-6, and Figure 2-7 on page 11 show the narrow-band blocking, and Figure 2-8 on page 12 shows the wide-band  
blocking characteristic. The measurements were done with a useful signal of 315MHz, FSK, 10Kbits/s, ±38kHz, Manchester,  
BR_Range2 with a level of –105dBm + 3dB = –102dBm, which is 3dB above the sensitivity level. The figures show how  
much larger than –102dBm a continuous wave signal can be, until the BER is higher than 10–3. The measurements were  
done at the 50Ω input shown in Figure 2-1 on page 6. At 3MHz, for example, the blocker can be 67.5dBC higher than –  
102dBm, or  
–102dBm + 67.5dBC = –34.5dBm.  
Figure 2-6. Close-in 3-dB Blocking Characteristic and Image Response at 315MHz  
70  
60  
50  
40  
30  
20  
10  
0
-10  
-2  
-1.5  
-1  
-0.5  
0
0.5  
1
1.5  
2
Distance from Interfering to Receiving Signal (MHz)  
Figure 2-7. Narrow-band 3-dB Blocking Characteristic at 315MHz  
80  
70  
60  
50  
40  
30  
20  
10  
0
-10  
-5  
-4  
-3  
-2  
-1  
0
1
2
3
4
5
Distance from Interfering to Receiving Signal (MHz)  
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Figure 2-8. Wide-band 3-dB Blocking Characteristic at 315MHz  
80  
70  
60  
50  
40  
30  
20  
10  
0
-10  
-50  
-40  
-30  
-20  
-10  
0
10  
20  
30  
40  
50  
Distance from Interfering to Receiving Signal (MHz)  
Table 2-8 shows the blocking performance measured relative to –102dBm for some frequencies. Note that sometimes the  
blocking is measured relative to the sensitivity level 104dBm (denoted dBS), instead of the carrier –102dBm (denoted dBC)  
Table 2-8. Blocking 3 dB Above Sensitivity Level With BER < 10–3  
Frequency Offset  
+1.5MHz  
–1.5MHz  
+2MHz  
Blocking Level  
–44.5dBm  
–44.5dBm  
–39.0dBm  
–36.0dBm  
–34.5dBm  
–34.5dBm  
–28.0dBm  
–28.0dBm  
Blocking  
57.5dBC, 60.5dBS  
57.5dBC, 60.5dBS  
63dBC, 66dBS  
–2MHz  
66dBC, 69dBS  
+3MHz  
67.5dBC, 70.5dBS  
67.5dBC, 70.5dBS  
74dBC, 77dBS  
–3MHz  
+20MHz  
–20MHz  
74dBC, 77dBS  
The Atmel® ATA5745C/ATA5746C can also receive FSK and ASK modulated signals if they are much higher than the  
I1dBCP. It can typically receive useful signals at –10dBm. This is often referred to as the nonlinear dynamic range (that is,  
the maximum to minimum receiving signal), and is 95dB for 10Kbits/s Manchester (FSK). This value is useful if the  
transmitter and receiver are very close to each other.  
2.7  
In-band Disturbers, Data Filter, Quasi-peak Detector, Data Slicer  
If a disturbing signal falls into the received band, or if a blocker is not a continuous wave, the performance of a receiver  
strongly depends on the circuits after the IF filter. Hence, the demodulator, data filter, and data slicer are important.  
The data filter of the Atmel ATA5745C/ATA5746C functions also as a quasi-peak detector. This results in a good suppression  
of above mentioned disturbers and exhibits a good carrier-to-noise performance. The required useful-signal-to-disturbing-  
signal ratio, at a BER of 10–3, is less than 14dB in ASK mode and less than 3dB (BR_Range_0 to BR_Range_2) and 6dB  
(BR_Range_3) in FSK mode. Due to the many different possible waveforms, these numbers are measured for the signal, as  
well as for disturbers, with peak amplitude values. Note that these values are worst-case values and are valid for any type of  
modulation and modulating frequency of the disturbing signal, as well as for the receiving signal. For many combinations,  
lower carrier-to-disturbing-signal ratios are needed.  
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2.8  
RSSI Output  
The output voltage of the pin RSSI is an analog voltage, proportional to the input power level. Using the RSSI output signal,  
the signal strength of different transmitters can be distinguished. The usable dynamic range of the RSSI amplifier is 65 dB,  
the input power range P(RFIN) is  
–110dBm to –45dBm, and the gain is 15mV/dB. Figure 2-9 shows the RSSI characteristic of a typical device at 315MHz with  
VS3V_AVCC = VS5V = 2.7V to 3.3V and Tamb = –40°C to +105°C with a matched input as shown in Table 2-2 and Figure 2-  
1 on page 6. At 433.92MHz, 1dB more signal level is needed for the same RSSI results.  
Figure 2-9. Typical RSSI Characteristic at 315MHz Versus Temperature and Supply Voltage  
1.7  
1.6  
1.5  
1.4  
min; -9dB  
1.3  
1.2  
1.1  
max; +9dB  
2.7V, -40°C  
3.0V, -40°C  
3.3V, -40°C  
2.7V, 27°C  
3.0V, 27°C  
3.3V, 27°C  
2.7V, 105°C  
3.0V, 105°C  
3.3V, 105°C  
1
0.9  
0.8  
0.7  
0.6  
0.5  
0.4  
-130 -120 -110 -100 -90 -80 -70 -60 -50 -40 -30 -20 -10  
Pin (dBm)  
As can be seen in Figure 2-9 on page 13, for single devices there is a variance over temperature and supply voltage range  
of ±3dB. The total variance over production, temperature, and supply voltage range is ±9dB.  
2.9  
Frequency Synthesizer  
The LO generates the carrier frequency for the mixer via a PLL synthesizer. The XTO (crystal oscillator) generates the  
reference frequency fXTO. The VCO (voltage-controlled oscillator) generates the drive voltage frequency fLO for the mixer. fLO  
is divided by the factor 24 (Atmel® ATA5746C) or 32 (Atmel ATA5745C). The divided frequency is compared to fXTO by the  
phase frequency detector. The current output of the phase frequency detector is connected to the fully integrated loop filter,  
and thereby generates the control voltage for the VCO. By means of that configuration, the VCO is controlled in a way, such  
that fLO / 24 (fLO / 32) is equal to fXTO. If fLO is determined, fXTO can be calculated using the following formula: fXTO = fLO / 24  
(fXTO = fLO / 32). The synthesizer has a phase noise of –130dBC/Hz at 3MHz and spurs of –75dBC.  
Care must be taken with the harmonics of the CLK output signal, as well as with the harmonics produced by a  
microprocessor clocked using the signal, as these harmonics can disturb the reception of signals.  
3.  
XTO  
The XTO is an amplitude-regulated Pierce oscillator type with external load capacitances (2 × 16pF). Due to additional  
internal and board parasitics (CP) of approximately 2pF on each side, the load capacitance amounts to 2 × 18pF (9pF total).  
The XTO oscillation frequency fXTO is the reference frequency for the integer-N synthesizer. When designing the system in  
terms of receiving and transmitting frequency offset, the accuracy of the crystal and XTO have to be considered.  
The XTO’s additional pulling (including the RM tolerance) is only ±5ppm. The XTAL versus temperature, aging, and  
tolerances is then the main source of frequency error in the local oscillator.  
The XTO frequency depends on XTAL properties and the load capacitances CL1,2 at pin XTAL1 and XTAL2. The pulling (p)  
of fXTO from the nominal fXTAL is calculated using the following formula:  
Cm  
------- ------------------------------------------------------------  
× 10 ppm  
C
LN CL  
-6  
p =  
×
2
(CO + CLN) × (CO + CL)  
ATA5745C/ATA5746C [DATASHEET]  
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Cm, the crystal's motional capacitance; C0, the shunt capacitance; and CLN, the nominal load capacitance of the XTAL, are  
found in the datasheet. CL is the total actual load capacitance of the crystal in the circuit, and consists of CL1 and CL2  
connected in series.  
Figure 3-1. Crystal Equivalent Circuit  
Crystal Equivalent Circuit  
C
0
XTAL  
L
R
m
m
C
m
C
C
L2  
L1  
C
= C x C /(C + C )  
L1 L2 L1 L2  
L
With Cm 10fF, C0 1.0pF, CLN = 9pF and CL1,2 = 16pF ±1%, the pulling amounts to P ±1ppm.  
The C0 of the XTAL has to be lower than CLmin / 2 = 7.9pF for a Pierce oscillator type in order to not enter the steep region of  
pulling versus load capacitance where there is risk of an unstable oscillation.  
To ensure proper start-up behavior, the small signal gain and the negative resistance provided by this XTO at start is very  
large. For example, oscillation starts up even in the worst case with a crystal series resistance of 1.5kΩ at C0 2.2pF with  
this XTO. The negative resistance is approximately given by  
Z × Z + Z × Z + Z × Z × gm  
1
3
2
3
1
3
----------------------------------------------------------------------------------  
Re{Zxtocore} = Re  
Z1 + Z2 + Z3 + Z1 × Z2 × gm  
with Z1 and Z2 as complex impedances at pins XTAL1 and XTAL2, hence  
Z1 = –j / (2 × p × fXTO × CL1) + 5Ω and Z2 = –j / (2 × p × fXTO × CL2) + 5Ω.  
Z3 consists of crystal C0 in parallel with an internal 110-kΩ resistor, hence  
Z3 = –j / (2 × p × fXTO × C0) / 110kΩ, gm is the internal transconductance between XTAL1 and XTAL2, with typically 20mS at  
25°C.  
With fXTO = 13.5MHz, gm = 20mS, CL = 9pF, and C0 = 2.2pF, this results in a negative resistance of about 2kΩ. The worst  
case for technology, supply voltage, and temperature variations is then always higher than 1.4kΩ for C0 2.2pF.  
Due to the large gain at start, the XTO is able to meet a very low start-up time. The oscillation start-up time can be estimated  
with the time constant τ.  
2
-----------------------------------------------------------------------------------------------------------  
τ =  
4 × π2 × fXTAL2 × Cm × (Re(Zxtocore) + Rm)  
After 10τ to 20τ, an amplitude detector detects the oscillation amplitude and sets XTO_OK to High if the amplitude is large  
enough; this activates the CLK_OUT output if it is enabled via the pins CLK_OUT_CTRL0 and CLK_OUT_CTRL1. Note that  
the necessary conditions of the DVCC voltage also have to be fulfilled.  
It is recommended to use a crystal with Cm = 3.0fF to 10fF, CLN = 9pF, Rm < 120Ω and C0 = 1.0pF to 2.2pF.  
Lower values of Cm can be used, slightly increasing the start-up time. Lower values of C0 or higher values of Cm (up to 15fF)  
can also be used, with only little influence on pulling.  
14  
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Figure 3-2. XTO Block Diagram  
CL1  
CL2  
XTAL1  
XTAL2  
CLK_OUT_CTRL0 CLK_OUT_CTRL1  
CLK_OUT  
&
fFXTO  
Divider  
/3, /6, /12  
XTO_OK  
Amplitude  
Detector  
Divider  
/16  
fDCLK  
The relationship between fXTO and the fRF is shown in Table 3-1.  
Table 3-1. Calculation of fRF  
Frequency [MHz]  
fXTO [MHz]  
fRF  
433.92 (Atmel ATA5745C)  
315.0 (Atmel ATA5746C)  
13.57375  
13.1433  
fXTO x 32 – 440kHz  
fXTO x 24 – 440kHz  
Attention must be paid to the harmonics of the CLK_OUT output signal fCLK_OUT as well as to the harmonics produced by an  
microprocessor clocked with it, since these harmonics can disturb the reception of signals if they get to the RF input. If the  
CLK_OUT signal is used, it must be carefully laid out on the application PCB. The supply voltage of the microcontroller must  
also be carefully blocked.  
3.1  
Pin CLK_OUT  
Pin CLK_OUT is an output to clock a connected microcontroller. The clock is available in Standby and Active modes. The  
frequency fCLK_OUT can be adjusted via the pins CLK_OUT_CTRL0 and CLK_OUT_CTRL1, and is calculated as follows:  
Table 3-2. Setting of fCLK_OUT  
CLK_OUT_CTRL1  
CLK_OUT_CTRL0  
Function  
Clock on pin CLK_OUT is switched off  
(Low level on pin CLK_OUT)  
0
0
0
1
1
1
0
1
fCLK_OUT = fXTO / 3  
fCLK_OUT = fXTO / 6  
fCLK_OUT = fXTO / 12  
The signal at CLK_OUT output has a nominal 50% duty cycle. To save current, it is recommended that CLK_OUT be  
switched off during Standby mode.  
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3.2  
Basic Clock Cycle of the Digital Circuitry  
The complete timing of the digital circuitry is derived from one clock. As seen in Figure 3-2 on page 15, this clock cycle,  
T
DCLK, is derived from the crystal oscillator (XTO) in combination with a divider.  
fXTO  
-----------  
=
fDCLK  
16  
TDCLK controls the following application relevant parameters:  
- Debouncing of the data signal stream  
- Start-up time of the RX signal path  
The start-up time and the debounce characteristic depend on the selected bit rate range (BR_Range) which is defined by  
pins BR0 and BR1. The clock cycle TXDCLK is defined by the following formulas for further reference:  
BR_Range   
BR_Range 0: TXDCLK = 8 × TDCLK  
BR_Range 1: TXDCLK = 4 × TDCLK  
BR_Range 2: TXDCLK = 2 × TDCLK  
BR_Range 3: TXDCLK = 1 × TDCLK  
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4.  
Sensitivity Reduction  
The output voltage of the RSSI amplifier is internally compared to a threshold voltage VTh_red. VTh_red is determined by the  
value of the external resistor RSense. RSense is connected between the pins SENSE and VS3V_AVCC (see Figure 10-1 on  
page 26). The output of the comparator is fed into the digital control logic. By this means, it is possible to operate the receiver  
at a lower sensitivity.  
If the level on input pin SENSE_CTRL is low, the receiver operates at full sensitivity.  
If the level on input pin SENSE_CTRL is high, the receiver operates at a lower sensitivity. The reduced sensitivity is defined  
by the value of RSense, the maximum sensitivity by the signal-to-noise ratio of the LNA input. The reduced sensitivity depends  
on the signal strength at the output of the RSSI amplifier.  
Since different RF input networks may exhibit slightly different values for the LNA gain, the sensitivity values given in the  
electrical characteristics refer to a specific input matching. This matching is illustrated in Figure 2-1 on page 6 and exhibits  
the best possible sensitivity.  
If the sensitivity reduction feature is not used, pin SENSE can be left open, pin SENSE_CTRL must be set to GND.  
To operate with reduced sensitivity, pin SENSE_CTRL must be set to high before the RX signal path will be enabled by  
setting pin RX to high (see Figure 4-1 on page 17). As long as the RSSI level is lower than VTh_red (defined by the external  
resistor RSense) no data stream is available on pin DATA_OUT (low level on pin DATA_OUT). An internal RS flip-flop will be  
set to high the first time the RSSI voltage crosses VTh_red, and from then on the data stream will be available on pin  
DATA_OUT. From then on the receiver also works with full sensitivity. This makes sure that a telegram will not be interrupted  
if the RSSI level varies during the transmission. The RS flip-flop can be set back, and thus the receiver switched back to  
reduced sensitivity, by generating a positive pulse on pin ASK_NFSK (see Figure 4-2 on page 18). In FSK mode, operating  
with reduced sensitivity follows the same way.  
Figure 4-1. Reduced Sensitivity Active  
ENABLE  
ASK_NFSK  
SENSE_CTRL  
RX  
V
Th_red  
RSSI  
t
t
Startup_PLL Startup_Sig_Proc  
DATA_OUT  
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Figure 4-2. Restart Reduced Sensitivity  
ENABLE  
ASK_NFSK  
SENSE_CTRL  
RX  
V
Th_red  
RSSI  
t
Startup_Sig_Proc  
DATA_OUT  
5.  
Power Supply  
Figure 5-1. Power Supply  
VS3V_AVCC  
SW_DVCC  
IN  
OUT  
V_REG  
3.0V typ.  
VS5V  
RX  
DVCC  
EN  
The supply voltage range of the Atmel® ATA5745C/ATA5746C is 2.7V to 3.3V or 4.5V to 5.5V.  
Pin VS3V_AVCC is the supply voltage input for the range 2.7V to 3.3V, and is used in battery applications using a single  
lithium 3V cell. Pin VS5V is the voltage input for the range 4.5V to 5.5V (car applications) in this case the voltage regulator  
V_REG regulates VS3V_AVCC to typically 3.0V. If the voltage regulator is active, a blocking capacitor of 2.2µF has to be  
connected to VS3V_AVCC (see Figure 10-1 on page 26).  
DVCC is the internal operating voltage of the digital control logic and is fed via the switch SW_DVCC by VS3V_AVCC.  
DVCC must be blocked on pin DVCC with 68nF (see Figure 9-1 on page 25 and Figure 10-1 on page 26).  
Pin RX is the input to activate the RX signal processing and set the receiver to Active mode.  
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5.1  
OFF Mode  
A low level on pin RX and ENABLE will set the receiver to OFF mode (low power mode). In this mode, the crystal oscillator is  
shut down and no clock is available on pin CLK_OUT. The receiver is not sensitive to a transmitter signal in this mode.  
Table 5-1. Standby Mode  
RX  
ENABLE  
Function  
0
0
OFF mode  
5.2  
Standby Mode  
The receiver activates the Standby mode if pin ENABLE is set to “1”.  
In Standby mode, the XTO is running and the clock on pin CLK_OUT is available after the start-up time of the XTO has  
elapsed (dependent on pin CLK_OUT_CTRL0 and CLK_OUT_CTRL1). During Standby mode, the receiver is not sensitive  
to a transmitter signal.  
In Standby mode, the RX signal path is disabled and the power consumption IStandby is typically 50µA (CLK_OUT output off,  
VS3V_AVCC = VS5V = 3V). The exact value of this current is strongly dependent on the application and the exact operation  
mode, therefore check the section “Electrical Characteristics: General” on page 27 for the appropriate application case.  
Table 5-2. Standby Mode  
RX  
ENABLE  
Function  
0
1
Standby mode  
Figure 5-2. Standby Mode (CLK_OUT_CTRL0 or CLK_OUT_CTRL1 = 1)  
CLK_OUT  
t
XTO_Startup  
ENABLE  
Standby Mode  
5.3  
Active Mode  
The Active mode is enabled by setting the level on pin RX to high. In Active mode, the RX signal path is enabled and if a  
valid signal is present it will be transferred to the connected microcontroller.  
Table 5-3. Active Mode  
RX  
ENABLE  
Function  
1
1
Active mode  
During TStartup_PLL the PLL is enabled and starts up. If the PLL is locked, the signal processing circuit starts up  
(TStartup_Sig_Proc). After the start-up time, all circuits are in stable condition and ready to receive. The duration of the start-up  
sequence depends on the selected bit rate range.  
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Figure 5-3. Active Mode  
CLK_OUT  
ENABLE  
RX  
DATA_OUT  
DATA_OUT valid  
t
I
t
Startup_Sig_Proc  
Startup_PLL  
Startup_PLL  
I
I
I
Active  
Standby  
Active  
Standby Mode  
Startup  
Active Mode  
Table 5-4. Start-up Time  
Atmel ATA5745C (433.92MHz)  
Atmel ATA5746C (315MHz)  
BR1  
BR0  
TStartup_PLL  
TStartup_Sig_Proc  
TStartup_PLL  
TStartup_Sig_Proc  
0
0
1
1
0
1
0
1
1096µs  
644µs  
417µs  
304µs  
1132µs  
665µs  
431µs  
324µs  
261µs  
269µs  
Table 5-5. Modulation Scheme  
ASK_NFSK  
RFIN at Pin LNA_IN  
fFSK_H  
fFSK_L  
Level at Pin DATA_OUT  
1
0
1
0
0
1
fASK on  
fASK off  
20  
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9249B–RKE–08/12  
 
6.  
Bit Rate Ranges  
Configuration of the bit rate ranges is carried out via the two pins BR0 and BR1. The microcontroller uses these two interface  
lines to set the corner frequencies of the band-pass data filter. Switching the bit rate ranges while the RF front end is in  
Active mode can be done on the fly and will not take longer than 100 µs if done while remaining in either ASK or FSK mode.  
If the modulation scheme is changed at the same time, the switching time is (TStartup_Sig_Proc, see Figure 7-1 on page 23).  
Each BR_Range is defined by a minimum edge-to-edge time. To maintain full sensitivity of the receiver, edge-to-edge  
transition times of incoming data should not be less than the minimum for the selected BR_Range.  
Table 6-1. BR Ranges ASK  
Minimum Edge-to-edge Edge-to-edge Time Period TEE  
Recommended Bit Rate  
(Manchester)(1)  
Time Period TEE of the  
of the Data Signal During the  
BR1 BR0 BR_Range  
Data Signal(2)  
Start-up Period(3)  
0
0
1
1
0
1
0
1
BR_Range0  
BR_Range1  
BR_Range2  
BR_Range3  
1.0Kbit/s to 2.5Kbits/s  
2.0Kbits/s to 5.0Kbits/s  
4.0Kbits/s to 10.0Kbits/s  
8.0Kbits/s to 10.0Kbits/s  
200µs  
100µs  
50µs  
200µs to 500µs  
100µs to 250µs  
50µs to 125µs  
50µs to 62.5µs  
50µs  
Table 6-2. BR Ranges FSK  
BR1 BR0 BR_Range  
Minimum Edge-to-edge Edge-to-edge Time Period TEE  
Recommended Bit Rate  
(Manchester)(1)  
Time Period TEE of the  
of the Data Signal During the  
Data Signal(2)  
Start-up Period(3)  
0
0
1
0
1
0
1
BR_Range0  
BR_Range1  
BR_Range2  
BR_Range3  
1.0Kbit/s to 2.5Kbits/s  
2.0Kbits/s to 5.0Kbits/s  
4.0Kbits/s to 10.0Kbits/s  
8.0Kbits/s to 20.0Kbits/s  
200µs  
100µs  
50µs  
200µs to 500µs  
100µs to 250µs  
50µs to 125µs  
25µs to 62.5µs  
1
25µs  
Note:  
If during the start-up period (TStartup_PLL + TStartup_Sig_Proc) there is no RF signal, the data filter settles to the  
noise floor, leading to noise on pin DATA_OUT.  
Notes: 1. As can be seen, a bit stream of, for example, 2.5Kbits/s can be received in BR_Range0 and BR_Range1  
(overlapping BR_Ranges). To get the full sensitivity, always use the lowest possible BR_Range (here,  
BR_Range0). The advantage in the next higher BR_Range (BR_Range1) is the shorter start-up period,  
meaning lower current consumption during Polling mode. Thus, it is a decision between sensitivity and current  
consumption.  
2. The receiver is also capable of receiving non-Manchester-modulated signals, such as PWM, PPM, VPWM,  
NRZ. In ASK mode, the header and blanking periods occurring in Keeloq-like protocols (up to 52ms) are  
supported.  
3. To ensure an accurate settling of the data filter during the start-up period (TStartup_PLL + TStartup_Sig_Proc), the  
edge-to-edge time TEE of the data signal (preamble) must be inside the given limits during this period.  
ATA5745C/ATA5746C [DATASHEET]  
21  
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Figure 6-1. Examples of Supported Modulation Formats  
T
T
T
T
T
T
EE  
EE  
EE  
EE  
EE  
EE  
MAN:  
PWM:  
Logic 0  
Logic 0  
Logic 1  
Logic 1  
T
T
T
T
EE  
EE  
EE  
EE  
Logic 0  
Logic 1  
T
T
T
EE  
EE  
EE  
VPWM:  
On Transition Low to High  
On Transition High to Low  
Logic 0  
Logic 1  
T
T
T
EE  
EE  
EE  
T
T
T
T
T
T
T
EE  
EE  
EE  
EE  
EE  
EE  
EE  
PPM:  
NRZ:  
Logic 0  
Logic 0  
Logic 1  
Logic 1  
T
EE  
Figure 6-2. Supported Header and Blanking Periods  
Preamble  
Header  
Data Burst  
Guard Time  
Data Burst  
22  
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7.  
ASK_NFSK  
The ASK_NFSK pin allows the microcontroller to rapidly switch the RF front end between demodulation modes. A logic 1 on  
this pin selects ASK mode, and a logic 0 FSK mode. The time to change modes (TStartup_Sig_Proc) depends on the bit rate  
range being selected (not current bit rate range) and is given in Table 5-4 on page 20. This response time is specified for  
applications that require an ASK preamble followed by FSK data (for typical TPM applications). During TStartup_Sig_Proc, the  
level on pin DATA_OUT is low.  
Figure 7-1. ASK Preamble 2.4Kbits/s followed by FSK Data 9.6Kbits/s  
ENABLE  
RX  
BR1  
BR0  
ASK_NFSK  
DATA_OUT  
Data valid BR0  
Data valid BR3  
T
Startup_Sig_Proc  
ATA5745C/ATA5746C [DATASHEET]  
23  
9249B–RKE–08/12  
8.  
Polling Current Calculation  
Figure 8-1. Polling Cycle  
ENABLE  
RX  
I
I
Active  
Active  
I
I
I
Standby  
Supply  
Standby  
T
T
T
(= 1 / Signal_Bitrate (average)  
Bitcheck  
(Startup Signal Processing)  
Startup_Sig_Proc  
(Startup RF-PLL)  
Startup_PLL  
In an RKE and TPM system, the average chip current in Polling mode, IPolling, is an important parameter. The polling period  
must be controlled by the connected microcontroller via the pins ENABLE and RX. The polling current can be calculated as  
follows:  
I
Polling = (TStartup_PLL / TPolling_Period) × IStartup_PLL + (TStartup_Sig_Proc / TPolling_Period) × IActive  
+
(TBitcheck / TPolling_Period) × IActive + (TPolling_Period – TStartup_PLL – TStartup_Sig_Proc – TBitcheck) / TPolling_Period × IStandby  
TStartup_PLL  
TStartup_Sig_Proc  
:
depends on 315MHz/433.92MHz application.  
depends on 315MHz/433.92MHz application and the selected bit  
rate range.  
:
TBitcheck  
TPolling_Period  
IStartup_PLL  
IActive  
:
depends on the signal bit rate (1 / Signal_Bit_Rate).  
depends on the transmitter telegram (preburst).  
depends on 3V or 5V application and the setting of pin CLK_OUT.  
depends on 3V or 5V application, ASK or FSK mode and the setting of  
pin CLK_OUT.  
:
:
:
IStandby  
:
depends on 3V or 5V application and the setting of pin CLK_OUT.  
Example:-  
315-MHz application (Atmel ATA5746C), bit rate: 9.6Kbits/s,  
T
Polling_Period = 8ms  
--> TStartup_PLL  
--> TStartup_Sig_Proc  
--> TBitcheck  
=
=
=
269µs  
324µs (Bit Rate Range 3)  
104µs  
3V application; ASK mode, CLK_OUT disabled  
--> IStartup_PLL  
--> IActive  
--> IStandby  
=
=
=
4.5mA  
6.5mA  
0.05mA  
--> IPolling = 0.545mA  
24  
ATA5745C/ATA5746C [DATASHEET]  
9249B–RKE–08/12  
9.  
3V Application  
Figure 9-1. 3V Application  
15nF  
output  
output  
output  
output  
input  
TEST2  
TEST3  
RSSI  
TEST1  
ATA5745C/  
ATA5746C  
CLK_OUT  
CLK_OUT_CTRL1  
SENSE_CTRL  
SENSE  
RF  
2.2pF  
IN  
CLK_OUT_CTRL0  
ENABLE  
LNA_IN  
68nH/36nH  
LNA_GND  
output  
315MHz/433.92MHz  
VSS VCC  
68nF  
18pF  
18pF  
68nF  
VCC = 2.7V to 3.3V  
Note:  
Paddle (backplane) must be connected to GND  
ATA5745C/ATA5746C [DATASHEET]  
25  
9249B–RKE–08/12  
10. 5V Application  
Figure 10-1. 5V Application with Reduced/Full Sensitivity  
15 nF  
output  
output  
output  
output  
output  
input  
TEST2  
TEST3  
RSSI  
TEST1  
ATA5745C/  
ATA5746C  
CLK_OUT  
SENSE_CTRL  
SENSE  
R
Sense  
CLK_OUT_CTRL1  
2.2pF  
CLK_OUT_CTRL0  
ENABLE  
LNA_IN  
RF  
IN  
LNA_GND  
output  
VSS VCC  
68nH/36nH  
315MHz/433.92MHz  
68nF  
18pF  
18pF  
2.2µF  
68nF  
VCC = 4.5V to 5.5V  
Note:  
Paddle (backplane) must be connected to GND  
26  
ATA5745C/ATA5746C [DATASHEET]  
9249B–RKE–08/12  
11. Absolute Maximum Ratings  
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating  
only and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of this  
specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.  
Parameters  
Symbol  
Tj  
Min.  
Max.  
+150  
+125  
+105  
+6  
Unit  
°C  
°C  
°C  
V
Junction temperature  
Storage temperature  
Ambient temperature  
Supply voltage VS5V  
Tstg  
–55  
–40  
Tamb  
VS  
ESD (Human Body Model ESD S 5.1)  
every pin  
HBM  
MM  
–4  
+4  
kV  
V
ESD (Machine Model JEDEC A115A)  
every pin  
–200  
–500  
+200  
ESD (Field Induced Charge Device Model ESD  
STM 5.3.1-1999) every pin  
FCDM  
Pin_max  
+500  
0
V
Maximum input level, input matched to 50Ω  
dBm  
12. Thermal Resistance  
Parameters  
Symbol  
Value  
Unit  
Junction ambient  
RthJA  
25  
K/W  
13. Electrical Characteristics: General  
All parameters refer to GND and are valid for Tamb = –40°C to +105°C, VVS3V_AVCC = VVS5V = 2.7V to 3.3V, and VVS5V = 4.5V to 5.5V.  
Typical values are given at VVS3V_AVCC = VVS5V = 3V, Tamb = 25°C, and fRF = 315MHz unless otherwise specified. Details about current  
consumption, timing, and digital pin properties can be found in the specific sections of the “Electrical Characteristics”.  
No. Parameters  
Test Conditions  
Pin(1)  
Symbol  
Min.  
Typ.  
Max.  
Unit Type*  
1
1.1  
2
OFF Mode  
VVS3V_AVCC = VVS5V 3V  
VVS5V = 5V  
CLK_OUT disabled  
10, 11  
10  
2
2
µA  
µA  
A
A
Supply current in OFF  
mode  
ISOFF  
Standby Mode  
XTO running  
V
VS3V_AVCC = VVS5V 3V  
10, 11  
10, 11  
IStandby  
50  
50  
80  
80  
µA  
µA  
ms  
A
A
A
CLK_OUT disabled  
Supply current  
Standby mode  
2.1  
XTO running  
VVS5V = 5V  
CLK_OUT disabled  
IStandby  
XTO startup  
XTAL: Cm = 5fF,  
C0 = 1.8pF, Rm = 15Ω  
2.2 System start-up time  
TXTO_Startup  
0.3  
0.8  
*) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter  
Note:  
1. Pin numbers in parenthesis were measured with RF_IN matched to 50Ω according to Figure 2-1 on page 6 with compo-  
nent values as in Table 2-2 on page 7 (RFIN).  
ATA5745C/ATA5746C [DATASHEET]  
27  
9249B–RKE–08/12  
13. Electrical Characteristics: General (Continued)  
All parameters refer to GND and are valid for Tamb = –40°C to +105°C, VVS3V_AVCC = VVS5V = 2.7V to 3.3V, and VVS5V = 4.5V to 5.5V.  
Typical values are given at VVS3V_AVCC = VVS5V = 3V, Tamb = 25°C, and fRF = 315MHz unless otherwise specified. Details about current  
consumption, timing, and digital pin properties can be found in the specific sections of the “Electrical Characteristics”.  
No. Parameters  
Test Conditions  
Pin(1)  
Symbol  
Min.  
Typ.  
Max.  
Unit Type*  
From Standby mode to  
Active mode  
BR_Range_3  
Atmel ATA5745C  
Atmel ATA5746C  
Active mode start-up  
time  
TStartup_PLL +  
TStartup_Sig_Proc  
2.3  
A
565  
593  
µs  
µs  
3
Active Mode  
Atmel ATA5746C  
Atmel ATA5745C  
14  
14  
fRF  
fRF  
313  
433  
317  
435  
MHz  
MHz  
A
A
RF operating frequency  
range  
3.1  
VVS3V_AVCC = VVS5V = 3V  
ASK mode  
CLK_OUT disabled  
SENSE_CTRL = 0  
10, 11  
10, 11  
10  
IActive  
IActive  
IActive  
IActive  
6.5  
6.7  
6.7  
6.9  
9.6  
9.8  
9.8  
10  
mA  
mA  
mA  
mA  
A
A
A
A
VVS3V_AVCC = VVS5V = 3V  
FSK mode  
CLK_OUT disabled  
SENSE_CTRL = 0  
Supply current Active  
mode  
3.2  
VVS5V = 5V  
ASK mode  
CLK_OUT disabled  
SENSE_CTRL = 0  
VVS5V = 5V  
FSK mode  
CLK_OUT disabled  
SENSE_CTRL = 0  
10  
VVS3V_AVCC = VVS5V = 3V  
TPolling_Period = 8ms  
BR_Range_3, ASK  
mode, CLK_OUT  
disabled  
Supply current Polling  
mode  
3.3  
10, 11  
IPolling  
545  
µA  
C
Data rate = 9.6Kbits/s  
FSK deviation  
fDEV = ±38kHz  
BER = 10–  
3
Tamb = 25°C  
Bit rate 9.6Kbits/s BR2  
Bit rate 2.4Kbits/s BR0  
(14)  
(14)  
PREF_FSK  
PREF_FSK  
–103  
–106  
–105  
–108  
–106.5 dBm  
–109.5 dBm  
B
B
Input sensitivity FSK  
3.4  
f
RF = 315MHz  
FSK deviation ±18kHz to  
±50kHz  
Bit rate 9.6Kbits/s BR2  
Bit rate 2.4Kbits/s BR0  
(14)  
(14)  
PREF_FSK  
PREF_FSK  
–101  
–104  
dBm  
dBm  
B
B
*) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter  
Note:  
1. Pin numbers in parenthesis were measured with RF_IN matched to 50Ω according to Figure 2-1 on page 6 with compo-  
nent values as in Table 2-2 on page 7 (RFIN).  
28  
ATA5745C/ATA5746C [DATASHEET]  
9249B–RKE–08/12  
13. Electrical Characteristics: General (Continued)  
All parameters refer to GND and are valid for Tamb = –40°C to +105°C, VVS3V_AVCC = VVS5V = 2.7V to 3.3V, and VVS5V = 4.5V to 5.5V.  
Typical values are given at VVS3V_AVCC = VVS5V = 3V, Tamb = 25°C, and fRF = 315MHz unless otherwise specified. Details about current  
consumption, timing, and digital pin properties can be found in the specific sections of the “Electrical Characteristics”.  
No. Parameters  
Test Conditions  
Pin(1)  
Symbol  
Min.  
Typ.  
Max.  
Unit Type*  
ASK 100% level of  
carrier, BER = 10–  
Tamb = 25°C  
3
Input sensitivity ASK  
fRF = 315MHz  
3.5  
3.6  
Bit rate 9.6Kbits/s BR2  
Bit rate 2.4Kbits/s BR0  
(14)  
(14)  
PREF_ASK  
PREF_ASK  
–109  
–112  
–111  
–114  
–112.5 dBm  
–115.5 dBm  
B
B
Sensitivity change at  
fRF = 433.92MHz  
compared to  
fRF = 315MHz to  
fRF = 433.92MHz  
P = PREF_ASK + ΔPREF1  
P = PREF_FSK + ΔPREF1  
(14)  
ΔPREF1  
+1  
dB  
B
fRF = 315MHz  
FSK fDEV = ±38kHz  
ΔfOFFSET ±160kHz  
ASK 100%  
ΔfOFFSET ±160kHz  
P = PREF_ASK + ΔPREF1  
ΔPREF2  
Sensitivity change  
versus temperature,  
supply voltage and  
frequency offset  
3.7  
(14)  
ΔPREF2  
+4.5  
–1.5  
B
+
P = PREF_FSK + ΔPREF1  
ΔPREF2  
+
RSense connected from  
pin SENSE to  
pin VS3V_AVCC  
dBm  
(peak  
level)  
PRef_Red  
RSense = 62kΩ  
fin = 433.92MHz  
–76  
–88  
–76  
–88  
dBm  
dBm  
dBm  
dBm  
C
C
C
C
Reduced sensitivity  
RSense = 82kΩ  
fin = 433.92MHz  
3.8  
RSense = 62kΩ  
fin = 315MHz  
RSense = 82 kΩ  
fin = 315 MHz  
Reduced sensitivity  
variation over full  
operating range  
RSense = 62kΩ  
RSense = 82kΩ  
PRed = PRef_Red + PΔRed  
ΔPRed  
–10  
+10  
dB  
Maximum frequency  
difference of fRF between  
receiver and transmitter  
in FSK mode (fRF is the  
center frequency of the  
FSK signal with  
Maximum frequency  
offset in FSK mode  
3.9  
(14)  
ΔfOFFSET  
–160  
+160  
kHz  
B
fBIT = 10Kbits/s  
fDEV = ±38kHz  
*) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter  
Note:  
1. Pin numbers in parenthesis were measured with RF_IN matched to 50Ω according to Figure 2-1 on page 6 with compo-  
nent values as in Table 2-2 on page 7 (RFIN).  
ATA5745C/ATA5746C [DATASHEET]  
29  
9249B–RKE–08/12  
13. Electrical Characteristics: General (Continued)  
All parameters refer to GND and are valid for Tamb = –40°C to +105°C, VVS3V_AVCC = VVS5V = 2.7V to 3.3V, and VVS5V = 4.5V to 5.5V.  
Typical values are given at VVS3V_AVCC = VVS5V = 3V, Tamb = 25°C, and fRF = 315MHz unless otherwise specified. Details about current  
consumption, timing, and digital pin properties can be found in the specific sections of the “Electrical Characteristics”.  
No. Parameters  
Test Conditions  
Pin(1)  
Symbol  
Min.  
Typ.  
Max.  
Unit Type*  
With up to 2dB  
loss of sensitivity.  
Note that the tolerable  
frequency offset is 12kHz  
lower for fDEV = ±50kHz  
than for fDEV = ±38kHz,  
hence,  
Supported FSK  
3.10  
(14)  
fDEV  
±18  
±38  
±50  
kHz  
B
frequency deviation  
ΔfOFFSET ±148kHz  
fRF = 315MHz  
(14)  
(14)  
NF  
NF  
fIF  
6.0  
7.0  
9
dB  
dB  
B
B
A
A
3.11 System noise figure  
fRF = 433.92MHz  
fRF = 433.92MHz  
fRF = 315MHz  
10  
440  
440  
kHz  
kHz  
3.12 Intermediate frequency  
fIF  
3dB bandwidth  
This value is for  
information only!  
Note that for crystal and  
system frequency offset  
calculations, ΔfOFFSET  
must be used.  
3.13 System bandwidth  
(14)  
(14)  
SBW  
IIP3  
435  
kHz  
A
Δfmeas1 = 1.8MHz  
Δfmeas2 = 3.6MHz  
fRF = 315MHz  
System out-band  
3.14 3rd-order input intercept  
point  
–24  
dBm  
C
fRF = 433.92MHz  
(14)  
(14)  
IIP3  
–23  
–31  
dBm  
dBm  
C
C
Δfmeas1 = 1MHz  
fRF = 315MHz  
I1dBCP  
–36  
–35  
System outband input 1-  
3.15  
dB compression point  
fRF = 433.92MHz  
fRF = 315MHz  
(14)  
14  
I1dBCP  
Zin_LNA  
Zin_LNA  
PIN_max  
PIN_max  
–30  
(72.4 – j298)  
(55 – j216)  
+5  
dBm  
Ω
C
C
C
C
C
C
C
3.16 LNA input impedance  
fRF = 433.92MHz  
14  
Ω
3
BER < 10 , ASK: 100%  
FSK: fDEV = ±38kHz  
f < 1GHz  
(14)  
(14)  
(14)  
(14)  
–10  
–10  
–57  
–47  
dBm  
dBm  
dBm  
dBm  
Maximum peak RF input  
3.17  
level, ASK and FSK  
+5  
f >1GHz  
fLO = 315.44MHz  
2 × fLO  
4 × fLO  
–90  
–94  
–68  
(14)  
(14)  
dBm  
dBm  
C
C
3.18 LO spurs at LNA_IN  
fLO = 434.36MHz  
2 × fLO  
4 × fLO  
–92  
–88  
–58  
With the complete image  
band  
fRF = 315MHz  
A
A
3.19 Image rejection  
(14)  
(14)  
24  
24  
30  
30  
dB  
dB  
fRF = 433.92MHz  
*) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter  
Note:  
1. Pin numbers in parenthesis were measured with RF_IN matched to 50Ω according to Figure 2-1 on page 6 with compo-  
nent values as in Table 2-2 on page 7 (RFIN).  
30  
ATA5745C/ATA5746C [DATASHEET]  
9249B–RKE–08/12  
13. Electrical Characteristics: General (Continued)  
All parameters refer to GND and are valid for Tamb = –40°C to +105°C, VVS3V_AVCC = VVS5V = 2.7V to 3.3V, and VVS5V = 4.5V to 5.5V.  
Typical values are given at VVS3V_AVCC = VVS5V = 3V, Tamb = 25°C, and fRF = 315MHz unless otherwise specified. Details about current  
consumption, timing, and digital pin properties can be found in the specific sections of the “Electrical Characteristics”.  
No. Parameters  
Test Conditions  
Pin(1)  
Symbol  
Min.  
Typ.  
Max.  
Unit Type*  
Peak level of useful  
signal to peak level of  
interferer for BER < 10–  
with any modulation  
scheme of interferer  
3
Useful signal to interferer  
ratio  
3.20  
FSK BR_Ranges 0, 1, 2  
FSK BR_Range_3  
(14)  
(14)  
SNRFSK0-2  
SNRFSK3  
SNRASK  
DRSSI  
2
4
3
6
dB  
dB  
dB  
dB  
B
B
B
A
ASK (PRF < PRFIN_High  
Dynamic range  
)
(14)  
10  
65  
14  
(14),17  
Lower level of range  
fRF = 315MHz  
fRF = 433.92MHz  
(14),17  
(14),17  
PRFIN_Low  
–110  
dBm  
dBm  
A
A
3.21 RSSI output  
Upper level of range  
f
RF = 315MHz  
PRFIN_High  
–45  
15  
fRF = 433.92MHz  
Gain  
(14),17  
(14),17  
mV/dB  
mV  
A
A
Output voltage range  
VRSSI  
RRSSI  
350  
8
1675  
12.5  
Output resistance  
RSSI pin  
3.22  
17  
10  
kΩ  
C
3
Sensitivity (BER = 10 )  
is reduced by 3dB if a  
continuous wave blocking  
signal at ±Δf is ΔPBlock  
higher than the useful  
signal level  
(Bit rate = 10Kbits/s,  
FSK, fDEV ±38kHz,  
Manchester code,  
BR_Range2)  
fRF = 315MHz  
Δf ±1.5MHz  
Δf ±2MHz  
Δf ±3MHz  
Δf ±10MHz  
Δf ±20MHz  
3.23 Blocking  
57.5  
63.0  
67.5  
72.0  
74.0  
(14)  
ΔPBlock  
dBC  
C
fRF = 433.92MHz  
Δf ±1.5MHz  
Δf ±2MHz  
Δf ±3MHz  
Δf ±10MHz  
Δf ±20MHz  
56.5  
62.0  
66.5  
71.0  
73.0  
(14)  
23  
ΔPBlock  
dBC  
nF  
C
D
Capacitor connected to  
pin 23 (CDEM)  
3.24 CDEM  
–5%  
15  
+5%  
*) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter  
Note:  
1. Pin numbers in parenthesis were measured with RF_IN matched to 50Ω according to Figure 2-1 on page 6 with compo-  
nent values as in Table 2-2 on page 7 (RFIN).  
ATA5745C/ATA5746C [DATASHEET]  
31  
9249B–RKE–08/12  
13. Electrical Characteristics: General (Continued)  
All parameters refer to GND and are valid for Tamb = –40°C to +105°C, VVS3V_AVCC = VVS5V = 2.7V to 3.3V, and VVS5V = 4.5V to 5.5V.  
Typical values are given at VVS3V_AVCC = VVS5V = 3V, Tamb = 25°C, and fRF = 315MHz unless otherwise specified. Details about current  
consumption, timing, and digital pin properties can be found in the specific sections of the “Electrical Characteristics”.  
No. Parameters  
Test Conditions  
Pin(1)  
Symbol  
Min.  
Typ.  
Max.  
Unit Type*  
4
XTO  
At startup; after startup  
the amplitude is regulated  
to VPPXTAL  
Transconductance XTO  
at start  
4.1  
7, 8  
gm, XTO  
20  
mS  
B
C0 2.2pF  
Cm < 14fF  
Rm 120Ω  
4.2 XTO start-up time  
7, 8  
7, 8  
TXTO_Startup  
C0max  
300  
800  
3.8  
µs  
pF  
A
D
4.3 Maximum C0 of XTAL  
Pulling of LO frequency  
1.0pF C0 2.2pF  
Cm = 4.0fF to 7.0fF  
fLO due to XTO, CL1 and  
CL2 versus temperature  
4.4  
3
ΔfXTO  
–5  
+5  
ppm  
C
R
m 120Ω  
and supply changes  
Cm = 5fF, C0 = 1.8pF  
m = 15Ω  
R
Amplitude XTAL after  
startup  
V(XTAL1, XTAL2)  
peak-to-peak value  
4.5  
7, 8  
7, 8  
VPPXTAL  
VPPXTAL  
700  
350  
mVpp  
mVpp  
C
C
V(XTAL1)  
peak-to-peak value  
C0 2.2pF, small signal  
start impedance, this  
value is important for  
crystal oscillator startup  
Maximum series  
4.6 resistance Rm of XTAL at  
startup  
7, 8  
ZXTAL12_START –1400  
–2000  
Ω
B
Maximum series  
4.7 resistance Rm of XTAL  
after startup  
C0 2.2pF  
Cm < 14fF  
7, 8  
7, 8  
Rm_max  
15  
120  
Ω
B
D
Nominal XTAL load  
4.8  
fRF = 433.92MHz  
fRF = 315MHz  
13.57375  
13.1433  
fXTAL  
MHz  
resonant frequency  
CLK_OUT_CRTL1 = 0  
CLK_OUT_CTRL0 = 0  
--> CLK_OUT disabled  
fCLK disabled (low level on pin  
CLK_OUT)  
CLK_OUT_CRTL1 = 0  
CLK_OUT_CTRL0 = 1  
--> division ratio = 3  
fXTO  
-----------  
3
fCLK  
fCLK  
fCLK  
=
=
=
External CLK_OUT  
frequency  
4.9  
3
fCLK_OUT  
MHz  
A
CLK_OUT_CRTL1 = 1  
CLK_OUT_CTRL0 = 0  
--> division ratio = 6  
fXTO  
-----------  
6
CLK_OUT_CRTL1 = 1  
CLK_OUT_CTRL0 = 1  
--> division ratio = 12  
fXTO  
-----------  
12  
*) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter  
Note:  
1. Pin numbers in parenthesis were measured with RF_IN matched to 50Ω according to Figure 2-1 on page 6 with compo-  
nent values as in Table 2-2 on page 7 (RFIN).  
32  
ATA5745C/ATA5746C [DATASHEET]  
9249B–RKE–08/12  
13. Electrical Characteristics: General (Continued)  
All parameters refer to GND and are valid for Tamb = –40°C to +105°C, VVS3V_AVCC = VVS5V = 2.7V to 3.3V, and VVS5V = 4.5V to 5.5V.  
Typical values are given at VVS3V_AVCC = VVS5V = 3V, Tamb = 25°C, and fRF = 315MHz unless otherwise specified. Details about current  
consumption, timing, and digital pin properties can be found in the specific sections of the “Electrical Characteristics”.  
No. Parameters  
Test Conditions  
Pin(1)  
Symbol  
Min.  
Typ.  
Max.  
Unit Type*  
fRF = 433.92MHz  
CLK_OUT division ratio  
= 3  
= 6  
= 12  
4.52458  
2.26229  
1.13114  
3
fCLK_OUT  
MHz  
D
CLK_OUT has nominal  
50% duty cycle  
fRF = 315MHz  
CLK_OUT division ratio  
= 3  
= 6  
4.3811  
2.190  
3
fCLK_OUT  
MHz  
mV  
D
C
= 12  
1.0952  
CLK_OUT has nominal  
50% duty cycle  
VDC (XTAL1, XTAL2)  
4.10 DC voltage after startup XTO running (Standby  
mode, Active mode)  
7,8  
VDCXTO  
–250  
–45  
5
Synthesizer  
At ±fCLK_OUT  
,
CLK_OUT enabled  
(division ratio = 3)  
fRF = 315MHz  
SPRX  
SPRX  
–75  
–75  
–70  
–70  
dBC  
dBC  
C
A
5.1 Spurs in Active mode  
fRF = 433.92MHz  
at ±fXTO  
fRF = 315MHz  
fRF = 433.92MHz  
Phase noise at 3MHz  
Active mode  
fRF = 315MHz  
fRF = 433.92MHz  
5.2  
LRX3M  
–130  
–135  
–127 dBC/Hz  
–132 dBC/Hz  
A
B
Phase noise at 20MHz  
Active mode  
5.3  
Noise floor  
LRX20M  
6
Microcontroller Interface  
fCLK_OUT < 4.5MHz  
CL = 10pF  
trise  
tfall  
20  
20  
30  
30  
ns  
ns  
CL = Load capacitance  
on pin CLK_OUT  
2.7V VVS5V 3.3V or  
4.5V VVS5V 5.5V  
20% to 80% VVS5V  
CLK_OUT output rise  
and fall time  
6.1  
3
3
C
C
Internal equivalent  
capacitance  
Used for current  
calculation  
6.2  
CCLK_OUT  
8
pF  
*) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter  
Note:  
1. Pin numbers in parenthesis were measured with RF_IN matched to 50Ω according to Figure 2-1 on page 6 with compo-  
nent values as in Table 2-2 on page 7 (RFIN).  
ATA5745C/ATA5746C [DATASHEET]  
33  
9249B–RKE–08/12  
14. Electrical Characteristic: 3V Application  
All parameters refer to GND and are valid for Tamb = –40°C to +105°C, VVS3V_AVCC = VVS5V = 2.7V to 3.3V, and VVS5V = 4.5V to 5.5V.  
Typical values are given at VVS3V_AVCC = VVS5V = 3V, Tamb = 25°C, and fRF = 433.92MHz unless otherwise specified. Details about  
current consumption, timing, and digital pin properties can be found in the specific sections of the “Electrical Characteristics”.  
No. Parameters  
Test Conditions  
Pin  
Symbol  
Min.  
Typ.  
Max.  
Unit  
Type*  
7
3V Application  
Supply current in OFF VVS3V_AVCC = VVS5V 3V  
7.1  
10, 11  
ISOFF  
2
µA  
A
mode  
CLK_OUT disabled  
VVS3V_AVCC  
=
VVS5V 3V  
external load C on pin  
CLK_OUT = 12pF  
CLK enabled  
(division ratio 3)  
CLK enabled  
(division ratio 6)  
CLK enabled  
(division ratio 12)  
CLK disabled  
C
C
C
A
420  
290  
220  
50  
670  
460  
350  
80  
Current in Standby  
mode (XTO is running)  
7.2  
10, 11  
IStandby  
µA  
VVS3V_AVCC  
VVS5V 3V  
CLK disabled  
VVS3V_AVCC  
Current in Active mode VVS5V 3V  
=
Current during  
TStartup_PLL  
7.3  
7.4  
10, 11  
10, 11  
IStartup_PLL  
4.5  
mA  
mA  
C
A
=
IActive  
6.5  
9.6  
9.8  
ASK  
CLK disabled  
SENSE_CTRL = 0  
VVS3V_AVCC  
Current in Active mode VVS5V 3V  
FSK  
=
7.5  
10, 11  
IActive  
6.7  
mA  
A
CLK disabled  
SENSE_CTRL = 0  
*) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter  
34  
ATA5745C/ATA5746C [DATASHEET]  
9249B–RKE–08/12  
15. Electrical Characteristics: 5V Application  
All parameters refer to GND and are valid for Tamb = –40°C to +105°C, VVS3V_AVCC = VVS5V = 2.7V to 3.3V, and VVS5V = 4.5V to 5.5V.  
Typical values are given at VVS3V_AVCC = VVS5V = 3V, Tamb = 25°C, and fRF = 433.92MHz unless otherwise specified. Details about  
current consumption, timing, and digital pin properties can be found in the specific sections of the “Electrical Characteristics”.  
No. Parameters  
Test Conditions  
Pin  
Symbol  
Min.  
Typ.  
Max.  
Unit  
Type*  
8
5V Application  
Supply current in OFF VVS5V = 5V  
8.1  
10  
ISOFF  
2
µA  
A
mode  
CLK_OUT disabled  
VVS5V 5V  
external load C on pin  
CLK_OUT = 12pF  
CLK enabled  
700  
490  
370  
1120  
780  
590  
80  
C
C
C
Current in Standby  
(division ratio 3)  
8.2  
10  
IStandby  
µA  
mode (XTO is running) CLK enabled  
(division ratio 6)  
CLK enabled  
(division ratio 12)  
CLK disabled  
50  
A
C
Current during  
TStartup_PLL  
VVS5V = 5V  
CLK disabled  
8.3  
8.4  
10  
10  
IStartup_PLL  
4.7  
mA  
mA  
VVS5V = 5V  
CLK disabled  
SENSE_CTRL = 0  
Current in Active mode  
ASK  
IActive  
6.7  
6.9  
9.8  
10  
A
A
VVS5V = 5V  
CLK disabled  
SENSE_CTRL = 0  
Current in Active mode  
FSK  
8.5  
10  
IActive  
mA  
*) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter  
ATA5745C/ATA5746C [DATASHEET]  
35  
9249B–RKE–08/12  
16. Digital Timing Characteristics  
All parameters refer to GND and are valid for Tamb = –40°C to +105°C, VVS3V_AVCC = VVS5V = 2.7V to 3.3V, and VVS5V = 4.5V to 5.5V.  
Typical values are given at VVS3V_AVCC = VVS5V = 3V, Tamb = 25°C, and fRF = 433.92MHz unless otherwise specified. Details about  
current consumption, timing, and digital pin properties can be found in the specific sections of the “Electrical Characteristics”  
No. Parameters  
Test Conditions  
Pin  
Symbol  
Min.  
Typ.  
Max.  
Unit  
Type*  
9
Basic Clock Cycle of the Digital Circuitry  
Basic clock cycle  
9.1  
TDCLK  
16 / fXTO  
16 / fXTO  
µs  
A
BR_Range_0  
8
8
BR_Range_1  
Extended basic clock  
BR_Range_2  
4
2
1
4
2
1
9.2  
10  
TXDCLK  
µs  
µs  
A
cycle  
BR_Range_3  
× TDCLK  
× TDCLK  
Active Mode  
15 µs +  
208 ×  
TDCLK  
10.1 Startup PLL  
TStartup_PLL  
A
A
BR_Range_0  
BR_Range_1  
BR_Range_2  
BR_Range_3  
929.5  
545.5  
TStartup_Sig_Proc 353.5  
257.5  
929.5  
545.5  
353.5  
257.5  
× TDCLK  
Startup signal  
10.2  
processing  
× TDCLK  
ASK  
BR_Range =  
BR_Range0  
BR_Range1  
BR_Range2  
BR_Range3  
FSK  
1.0  
2.0  
4.0  
2.5  
5.0  
10.0  
10.0  
8.0  
10.3 Bit rate range  
BR_Range  
Kbits/s  
A
BR_Range =  
BR_Range0  
BR_Range1  
BR_Range2  
BR_Range3  
1.0  
2.0  
4.0  
8.0  
2.5  
5.0  
10.0  
20.0  
BR_Range_0  
BR_Range_1  
BR_Range_2  
BR_Range_3  
Minimum time period  
10.4 between edges at pin  
DATA_OUT  
10 ×  
TDATA_OUT_min  
TXDCLK  
24  
µs  
µs  
A
B
Edge-to-edge time  
period of the data  
BR_Range_0  
BR_Range_1  
signal for full sensitivity BR_Range_2  
200  
500  
250  
125  
62.5  
100  
50  
10.5  
TDATA_OUT  
in Active mode  
BR_Range_3  
25  
*) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter  
36  
ATA5745C/ATA5746C [DATASHEET]  
9249B–RKE–08/12  
17. Digital Port Characteristics  
All parameters refer to GND and are valid for Tamb = –40°C to +105°C, VVS3V_AVCC = VVS5V = 2.7V to 3.3V, and VVS5V = 4.5V to 5.5V.  
Typical values are given at VVS3V_AVCC = VVS5V = 3V, Tamb = 25°C, and fRF = 433.92MHz unless otherwise specified. Details about  
current consumption, timing, and digital pin properties can be found in the specific sections of the “Electrical Characteristics”  
No. Parameters  
Test Conditions  
Pin  
Symbol  
Min.  
Typ.  
Max.  
Unit  
Type*  
11  
Digital Ports  
VS = VVS3V_AVCC  
VVS5V = 2.7V to 3.3V  
=
0.2 × VS  
ENABLE input  
- Low level input  
voltage  
6
VIl  
V
A
VS = VVS5V  
=
0.12 × VS  
4.5V to 5.5V  
11.1  
VS = VVS3V_AVCC  
=
VVS5V = 2.7V to 3.3V  
- High level input  
voltage  
6
VIh  
0.8 × VS  
V
V
V
V
V
V
V
V
V
A
A
A
A
A
A
A
A
A
VS = VVS5V = 4.5V to  
5.5V  
VS = VVS3V_AVCC  
=
0.2 × VS  
RX input  
- Low level input  
voltage  
VVS5V = 2.7V to 3.3V  
19  
19  
20  
20  
21  
21  
22  
22  
VIl  
VS = VVS5V  
=
0.12 × VS  
4.5V to 5.5V  
11.2  
11.3  
11.4  
11.5  
VS = VVS3V_AVCC  
=
VVS5V = 2.7V to 3.3V  
- High level input  
voltage  
VIh  
0.8 × VS  
0.8 × VS  
0.8 × VS  
0.8 × VS  
VS = VVS5V  
=
4.5V to 5.5V  
VS = VVS3V_AVCC  
=
0.2 × VS  
BR0 input  
- Low level input  
voltage  
VVS5V = 2.7V to 3.3V  
VIl  
VS = VVS5V  
=
0.12 × VS  
4.5V to 5.5V  
VS = VVS3V_AVCC  
=
VVS5V = 2.7V to 3.3V  
- High level input  
voltage  
VIh  
VS = VVS5V  
=
4.5V to 5.5V  
VS = VVS3V_AVCC  
=
BR1 input  
- Low level input  
voltage  
VVS5V = 2.7V to 3.3V  
0.2 × VS  
VIl  
VS = VVS5V  
=
0.12 × VS  
4.5V to 5.5V  
VS = VVS3V_AVCC  
=
VVS5V = 2.7V to 3.3V  
- High level input  
voltage  
VIh  
VS = VVS5V  
=
4.5V to 5.5V  
VS = VVS3V_AVCC  
=
ASK_NFSK input  
- Low level input  
voltage  
VVS5V = 2.7V to 3.3V  
0.2 × VS  
VIl  
VS = VVS5V  
=
0.12 × VS  
4.5V to 5.5V  
VS = VVS3V_AVCC  
=
VVS5V = 2.7V to 3.3V  
VS = VVS5V  
4.5V to 5.5V  
- High level input  
voltage  
VIh  
=
*) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter  
ATA5745C/ATA5746C [DATASHEET]  
37  
9249B–RKE–08/12  
17. Digital Port Characteristics (Continued)  
All parameters refer to GND and are valid for Tamb = –40°C to +105°C, VVS3V_AVCC = VVS5V = 2.7V to 3.3V, and VVS5V = 4.5V to 5.5V.  
Typical values are given at VVS3V_AVCC = VVS5V = 3V, Tamb = 25°C, and fRF = 433.92MHz unless otherwise specified. Details about  
current consumption, timing, and digital pin properties can be found in the specific sections of the “Electrical Characteristics”  
No. Parameters  
Test Conditions  
Pin  
Symbol  
Min.  
Typ.  
Max.  
Unit  
Type*  
VS = VVS3V_AVCC  
VVS5V = 2.7V to 3.3V  
=
0.2 × VS  
SENSE_CTRL input  
- Low level input  
voltage  
16  
VIl  
V
A
VS = VVS5V  
=
0.12 × VS  
4.5V to 5.5V  
11.6  
11.7  
11.8  
VS = VVS3V_AVCC  
VVS5V = 2.7V to 3.3V  
=
- High level input  
voltage  
16  
5
VIh  
0.8 × VS  
V
V
V
V
V
A
A
A
A
A
VS = VVS5V  
=
4.5V to 5.5V  
VS = VVS3V_AVCC  
VVS5V = 2.7V to 3.3V  
=
CLK_OUT_CTRL0  
input  
- Low level input  
voltage  
0.2 × VS  
VIl  
VS = VVS5V  
=
0.12 × VS  
4.5V to 5.5V  
VS = VVS3V_AVCC  
=
=
VVS5V = 2.7V to 3.3V  
- High level input  
voltage  
5
VIh  
0.8 × VS  
VS = VVS5V  
=
4.5V to 5.5V  
VS = VVS3V_AVCC  
VVS5V = 2.7V to 3.3V  
CLK_OUT_CTRL1  
input  
- Low level input  
voltage  
0.2 × VS  
4
VIl  
VS = VVS5V  
=
0.12 × VS  
4.5V to 5.5V  
VS = VVS3V_AVCC  
VVS5V = 2.7V to 3.3V  
=
- High level input  
voltage  
4
VIh  
0.8 × VS  
VS = VVS5V  
=
4.5V to 5.5V  
TEST1 input must  
always be connected  
directly to GND  
11.9 TEST1 input  
11.10 TEST2 output  
11.11 TEST3 input  
2
1
0
0
0
0
0
0
V
V
V
D
D
D
TEST2 output must  
always be connected  
directly to GND  
TEST3 input must  
always be connected  
directly to GND  
18  
*) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter  
38  
ATA5745C/ATA5746C [DATASHEET]  
9249B–RKE–08/12  
17. Digital Port Characteristics (Continued)  
All parameters refer to GND and are valid for Tamb = –40°C to +105°C, VVS3V_AVCC = VVS5V = 2.7V to 3.3V, and VVS5V = 4.5V to 5.5V.  
Typical values are given at VVS3V_AVCC = VVS5V = 3V, Tamb = 25°C, and fRF = 433.92MHz unless otherwise specified. Details about  
current consumption, timing, and digital pin properties can be found in the specific sections of the “Electrical Characteristics”  
No. Parameters  
Test Conditions  
Pin  
Symbol  
Min.  
Typ.  
Max.  
Unit  
Type*  
VS = VVS3V_AVCC  
=
VVS5V = 2.7V to 3.3V  
DATA_OUT output  
- Saturation voltage  
low  
VS = VVS5V  
=
24  
Vol  
0.15  
0.4  
V
B
4.5V to 5.5V  
IDATA_OUT = 250µA  
11.12  
VS = VVS3V_AVCC  
=
VVS5V = 2.7V to 3.3V  
- Saturation voltage  
high  
VVS –  
0.15  
VS = VVS5V  
=
24  
Voh  
VVS – 0.4  
V
V
V
B
B
B
4.5V to 5.5V  
IDATA_OUT = –250µA  
VS = VVS3V_AVCC  
=
VVS5V = 2.7V to 3.3V  
CLK_OUT output  
- Saturation voltage  
low  
VS = VVS5V  
=
3
Vol  
0.15  
0.4  
4.5V to 5.5V  
IDATA_OUT = 100µA  
11.13  
VS = VVS3V_AVCC  
=
VVS5V = 2.7V to 3.3V  
- Saturation voltage  
high  
VVS –  
0.15  
VS = VVS5V  
=
3
Voh  
VVS – 0.4  
4.5V to 5.5V  
IDATA_OUT = –100µA  
*) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter  
ATA5745C/ATA5746C [DATASHEET]  
39  
9249B–RKE–08/12  
18. Ordering Information  
Extended Type Number  
ATA5745C-PXPW  
Package  
QFN24  
QFN24  
QFN24  
QFN24  
MOQ  
Remarks  
1500pcs  
1500pcs  
6000pcs  
6000pcs  
5mm × 5mm, Pb-free, 433.92MHz  
5mm × 5mm, Pb-free, 315MHz  
5mm × 5mm, Pb-free, 433.92MHz  
5mm × 5mm, Pb-free, 315MHz  
ATA5746C-PXPW  
ATA5745C-PXQW  
ATA5746C-PXQW  
19. Package Information  
Package: QFN 24 - 5 x 5  
Exposed pad 3.6 x 3.6  
(acc. JEDEC OUTLINE No. MO-220)  
Dimensions in mm  
Not indicated tolerances ±0.05  
5
0.9±0.1  
+0  
0.05-0.05  
3.6  
24  
19  
24  
1
6
18  
13  
1
6
technical drawings  
according to DIN  
specifications  
12  
0.65 nom.  
7
Drawing-No.: 6.543-5122.01-4  
Issue: 1; 15.11.05  
3.25  
20. Revision History  
Please note that the following page numbers referred to in this section refer to the specific revision mentioned, not to this  
document.  
Revision No.  
History  
Section 13 “Electrical Characteristics: General” on pages 27 to 33 changed  
Section 14 “Electrical Characteristic: 3V Application” on page 34 changed  
Section 15 “Electrical Characteristic: 5V Application” on page 35 changed  
9249B-RKE-08/12  
40  
ATA5745C/ATA5746C [DATASHEET]  
9249B–RKE–08/12  
X
X X X X  
X
Atmel Corporation  
1600 Technology Drive, San Jose, CA 95110 USA  
T: (+1)(408) 441.0311  
F: (+1)(408) 436.4200  
|
www.atmel.com  
© 2014 Atmel Corporation. / Rev.: Rev.: 9249B–RKE–08/12  
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