RFRXD0920_技术文档

rfRXD0420/0920

UHF ASK/FSK/FM Receiver

Features:

Pin Diagram:

• Low cost single conversion superheterodyne

receiver architecture

LQFP

• Compatible with rfPIC™ and rfHCS series of RF

transmitters

®

• Easy interface to PICmicro microcontroller

®

(MCU) and KEELOQ decoders

V

SS

1

2

3

4

5

6

7

8

24

23

22

21

20

19

18

17

DEMOUT

SS

-

• VCO phase locked to quartz crystal reference:

- Narrow receiver bandwidth

+

LNAGAIN

LNAOUT

1IFIN

V

rfRXD0420

rfRXD0920

RSSI

OPA+

OPA-

OPA

- Maximizes range and interference immunity

VSS

1IF+

1IF-

• Selectable LNA gain control for improved dynamic

range

VDD

• Selectable IF bandwidth via external ceramic IF

filter

• Received Signal Strength Indicator (RSSI) for

signal strength indication (FSK, FM) and ASK

demodulation

• FSK/FM quadrature (phase coincidence) detector

demodulator

• 32-Lead LQFP package

Applications:

UHF ASK/FSK Receiver:

• Wireless remote command and control

• Wireless security systems

• Remote Keyless Entry (RKE)

• Low power telemetry

• Single frequency receiver set by crystal frequency

• Receive frequency range:

Device

rfRXD0420

Frequency Range

300 MHz to 450 MHz

800 MHz to 930 MHz

• Low power FM receiver

• Home automation

rfRXD0920

• Remote sensing

• Maximum data rate:

- ASK: 80 Kbps NRZ

- FSK: 40 Kbps NRZ

Bi-CMOS Technology:

• Wide operating voltage range

• IF frequency range: 455 kHz to 21.4 MHz

• RSSI range: 70 dB

• Low current consumption in Active and Standby

modes

• Frequency deviation range: 5 kHz to 120 kHz

• Maximum FM modulation frequency: 15 kHz

- rfRXD0420

- 8.2 mA (typical, LNA High Gain mode)

- <100 nA standby

- rfRXD0920

- 9.2 mA (typical, LNA High Gain mode)

- <100 nA standby

• Wide temperature range:

- Industrial: -40°C to +85°C

 2003 Microchip Technology Inc.

Preliminary

DS70090A-page 1

rfRXD0420/0920

The rfRXD0420/0920 is a single conversion superhet-

erodyne architecture. A block diagram is illustrated in

Figure 1-1. The rfRXD0420/0920 consists of:

1.0

DEVICE OVERVIEW

The rfRXD0420/0920 are low cost, compact single

frequency short-range radio receivers requiring only a

minimum number of external components for a

complete receiver system. The rfRXD0420 covers the

receive frequency range of 300 MHz to 450 MHz and

the rfRXD0920 covers 800 MHz to 930 MHz. The

rfRXD0420 and rfRXD0920 share a common architec-

ture. They can be configured for Amplitude Shift Keying

(ASK), Frequency Shift Keying (FSK), or FM modula-

tion. The rfRXD0420/0920 are compatible with rfPIC™

and rfHCS series of RF transmitters.

• Low-noise amplifier (LNA) - Gain selectable

• Mixer for down-conversion of the RF signal to the

Intermediate Frequency (IF) followed by an IF

preamplifier

• Fully integrated Phase-Locked Loop (PLL)

frequency synthesizer for generation of the Local

Oscillator (LO) signal. The frequency synthesizer

consists of:

- Crystal oscillator

- Phase-frequency detector and charge pump

• High frequency stability over temperature and

power supply variations

- High-frequency Voltage Controlled Oscillator

(VCO)

• Low spurious signal emission

- Fixed feedback divider

- rfRXD0420 = divide by 16

- rfRXD0920 = divide by 32

• High large-signal handling capability with

selectable LNA gain control for improved dynamic

range

• Selectable IF bandwidth via external low cost

ceramic IF filter. The IF Frequency range is

selectable between 455 kHz to 21.4 MHz. This

facilitates the use of readily available low cost

10.7 MHz ceramic IF filters in a variety of

bandwidths.

• IF limiting amplifier to amplify and limit the IF

signal and for Received Signal Strength Indication

(RSSI) generation

• Demodulator (DEMOD) section consists of a

phase detector (MIXER2) and amplifier creating a

quadrature detector (also known as a phase

coincidence detector) to demodulate the IF signal

in FSK and FM modulation applications

• ASK or FSK for digital data reception

• FM modulation for analog signal reception

• FSK/FM demodulation using quadrature detector

(phase coincidence detector)

• Operational amplifier (OPA) that can be config-

ured as a comparator for ASK or FSK data

decision or as a filter for FM modulation.

• Received Signal Strength Indication (RSSI) for

signal strength indication and ASK detection

• Bias circuitry for bandgap biasing and circuit

shutdown

• Wide supply voltage range

• Low active current consumption

• Very low standby current

DS70090A-page 2

Preliminary

 2003 Microchip Technology Inc.

rfRXD0420/0920

FIGURE 1-1: rfRXD0420/0920 BLOCK DIAGRAM

O P A

S S V

D D V

M I X E R 2

O U T + D E M

I N

D E M

O U T -

O U T 2 I F

D D V

F B C 2

F B C 1

S S V

X T A L

I N 2 I F

S S V

D D V

O U T 1 I F

E N R X

L F

D D V

1 I F -

1 I F +

S S V

1 I F

I N

O U T L N A

G A I N L N A

S S V

 2003 Microchip Technology Inc.

Preliminary

DS70090A-page 3

rfRXD0420/0920

TABLE 1-1:

rfRXD0420/0920 PINOUT I/O DESCRIPTION

Pin Name

Pin Number

Pin Type

Buffer Type

Description

LNAGAIN

LNAOUT

1IFIN

2

I

O

I

CMOS

Analog

CMOS

Analog

LNA gain control (with hysteresis)

LNA output (open collector)

1st IF stage input

3

4

1IF+

6

--

O

I

MIXER1 bias (open collector)

1st IF stage output

1IF-

7

1IFOUT

2IFIN

9

11

12

13

15

16

18

19

20

21

23

24

26

28

29

2nd IF stage input

FBC1

FBC2

2IFOUT

DEMIN

OPA

--

O

I

Limiter IF Amplifier external feedback capacitor

2nd IF stage output

Demodulator input

O

I

Operational amplifier output

Operational amplifier input (negative)

Operational amplifier input (positive)

Received signal strength indicator output

Demodulator output (positive)

Demodulator output (negative)

Crystal oscillator input

OPA-

OPA+

RSSI

I

O

I

DEMOUT+

DEMOUT-

XTAL

ENRX

LF

I

Receiver enable input

I

External loop filter connection. Common node of

charge pump output and VCO tuning input.

LNAIN

VDD

31

I

Analog

LNA input

8, 14, 17, 27, 32

1, 5, 10, 25, 30

P

Positive supply

Ground reference

VSS

Legend: I = Input, O = Output, I/O = Input/Output, P = Power, CMOS = CMOS compatible input or output

DS70090A-page 4

Preliminary

 2003 Microchip Technology Inc.

rfRXD0420/0920

The PLL consists of a phase-frequency detector,

charge pump, voltage-controlled oscillator (VCO), and

fixed divide-by-16 (rfRXD0420) or divide-by-32

(rfRXD0920) divider. The rfRXD0420/0920 employs a

charge pump PLL that offers many advantages over

the classical voltage phase detector PLL: infinite pull-in

range and zero steady state phase error. The charge

pump PLL allows the use of passive loop filters that are

lower cost and minimize noise. Charge pump PLLs

have reduced flicker noise thus limiting phase noise.

2.0

CIRCUIT DESCRIPTION

This section gives a circuit description of the internal

circuitry of the rfRXD0420/0920 receiver. External

connections and components are given in the

APPLICATION CIRCUITS section.

2.1

Bias Circuitry

Bias circuitry provides bandgap biasing and circuit

shutdown capabilities. The ENRX (Pin 28) modes are

summarized in Table 2-1. The ENRX pin is a CMOS

compatible input and is internally pulled down to Vss.

An external loop filter is connected to pin LF (Pin 29).

The loop filter controls the dynamic behavior of the

PLL, primarily lock time and spur levels. The applica-

tion determines the loop filter requirements.

TABLE 2-1: BIAS CIRCUITRY CONTROL

(1)

ENRX

Description

The VCO gain for the rfRXD0420/0920 receivers are

listed in Table 2-2.

0

1

Standby mode

Receiver enabled

TABLE 2-2: PLL PARAMETERS

Note 1: ENRX has internal pull-down to Vss

(1)

KVCO

(1)

Device

Divider

ICP

rfRXD0420 250 MHz/V at

433 MHz

60 µA

16

2.2

Frequency Synthesizer

rfRXD0920 300 MHz/V at

868 MHz

32

The Phase-locked Loop (PLL) frequency synthesizer

generates the Local Oscillator (LO) signal. It consists

of:

Note 1: Typical value

• Crystal oscillator

The LF pin is illustrated in Figure 2-2.

• Phase-frequency detector and charge pump

• Voltage Controlled Oscillator (VCO)

• Fixed feedback divider:

FIGURE 2-2: BLOCK DIAGRAM OF LOOP

FILTER PIN

- rfRXD0420 = divide by 16

- rfRXD0920 = divide by 32

200 Ω

2.2.1 CRYSTAL OSCILLATOR

VDD

The internal crystal oscillator is a Colpitts type oscilla-

tor. It provides the reference frequency to the PLL. A

crystal is normally connected to the XTAL (Pin 26) and

ground. The internal capacitance of the crystal oscilla-

tor is 15 pF. Alternatively, a signal can be injected into

the XTAL pin from a signal source. The signal should

be AC coupled via a series capacitor at a level of

LF

29

400 Ω

VSS

4 pF

VSS

approximately 600 mV

.

pp

2.3

Low Noise Amplifier

The XTAL pin is illustrated in Figure 2-1.

The Low-Noise Amplifier (LNA) is a high-gain amplifier

whose primary purpose is to lower the overall noise

figure of the entire receiver thus enhancing the receiver

sensitivity. The LNA is an open-collector cascode

design. The benefits of a cascode design are:

FIGURE 2-1:

BLOCK DIAGRAM OF

XTAL PIN

VDD

• high gain with low noise

• high-frequency

VDD

50 kΩ

XTAL

26

• wide bandwidth

30 pF

• low effective input capacitance with stable input

impedance

VSS

40 µA

• high output resistance

VSS

• high reverse isolation that provides improved

stability and reduces LO leakage

 2003 Microchip Technology Inc.

Preliminary

DS70090A-page 5

rfRXD0420/0920

Approximate LNA noise figures are listed in Table 2-3.

The 1IF+ (Pin 6) and 1IF- (Pin 7) are bias connections

to the MIXER1 balanced collectors. Both pins are

open-collector outputs and are individually pulled up to

VDD by a load resistor. The MIXER1 bias pins are illus-

trated in Figure 2-5.

TABLE 2-3: LNA NOISE FIGURES

(1)

Device

Noise Figure

rfRXD0420

TBD

1IFOUT (Pin 9) has an approximately 330 Ω single-

ended output impedance. The 330 Ω impedance

provides a direct match to low cost ceramic IF filters.

The 1IFOUT pins is illustrated in Figure 2-6.

rfRXD0920

Note 1: Approximate value

LNAIN (Pin 31) has an input impedance of approxi-

mately 26 Ω || 2 pF single-ended.

FIGURE 2-4: BLOCK DIAGRAM OF MIXER1

LNAOUT (Pin 3) has an open-collector output and is

pulled up to VDD via a tuned circuit.

VDD

Important: To ensure LNA stability the VSS pin (Pin 1)

13 Ω

must be connected to a low impedance ground.

1IFIN

The LNA pins are illustrated in Figure 2-3.

4

13 Ω

500 µA

VSS

FIGURE 2-3: BLOCK DIAGRAM OF LNA

PINS

VSS

LNAOUT

3

1.6V

FIGURE 2-5: BLOCK DIAGRAM OF MIXER1

BIAS PINS

0.8V

VDD

VSS

VDD

5 kΩ

VDD

LNAIN

31

20 pF

1IF-

1IF+

6

VSS

1

7

VSS

500 µA

VSS

500 µA

VSS

The gain of the LNA can be selected between High and

Low Gain modes by the LNAGAIN pin (Pin 2). LNAGAIN

is a CMOS input with hysteresis. Table 2-4 summarizes

the voltage levels and modes for LNA gain.

VSS

FIGURE 2-6: BLOCK DIAGRAM OF IF

PREAMP PIN

In the High Gain mode the LNA operates normally. In

Low Gain mode the gain of the LNA is reduced approx-

imately 25 dB, reduces total supply current, and

increases maximum input signal levels (see Electrical

Characteristics section for values).

VDD

6.8 kΩ

130 Ω

1IFOUT

9

TABLE 2-4: LNA GAIN CONTROL

230 µA

VSS

LNAGAIN

Description

VSS

< 0.8 V

> 1.4 V

High Gain mode

Low Gain mode

2.5

IF Limiting Amplifier with RSSI

The IF Limiting Amplifier amplifies and limits the IF

signal at the 2IFIN pin (Pin 11). It also generates the

Received Signal Strength Indicator (RSSI) signal

(Pin 21).

2.4

MIXER1 and IF Preamp

MIXER1 performs down-conversion of the RF signal to

the Intermediate Frequency (IF) and is followed by an

IF preamplifier.

2.5.1 IF LIMITING AMPLIFIER

1IFIN (Pin 4) has an approximately 33 Ω single-ended

Magnitude control circuitry is used in the last stage of

the receiver to keep the signal constant for demodula-

tion. It can consist of a limiting or Automatic Gain

input impedance. The 1IFIN pin is illustrated in Figure 2-

4.

Control (AGC) amplifier.

A limiting amplifier is

DS70090A-page 6

Preliminary

 2003 Microchip Technology Inc.

rfRXD0420/0920

employed in this design because it can handle a larger

dynamic range while consuming less power with simple

circuitry than AGC circuitry.

For FSK and FM demodulation, the RSSI represents

the received signal strength of the incoming RF signal.

The RSSI pin is illustrated in Figure 2-9.

The internal resistance of the 2IFIN pin is approximately

2.2 kΩ. In order to terminate ceramic IF filters whose

output impedance is 330 Ω, a 390 Ω resistor can be

paralleled to the 2IFIN and FBC2 pins.

FIGURE 2-9: BLOCK DIAGRAM OF RSSI

VDD

FBC1 (Pin 12) and FBC2 (Pin 13) are connected to

external feedback capacitors.

I (Pi)

50 Ω

RSSI

The IF Limiting Amplifier pins are illustrated in

Figures 2-7 and 2-8.

21

36 kΩ

VSS

FIGURE 2-7: BLOCK DIAGRAM OF IF

LIMITING AMPLIFIER INPUT

PINS

2.6

Demodulator

The demodulator (DEMOD) section consists of a phase

detector (MIXER2) and amplifier creating a quadrature

detector (also known as a phase coincidence detector)

to demodulate the IF signal in FSK and FM modulation

applications. The quadrature detector provides all the

IF functions required for FSK and FM demodulation

with only a few external parts.

VDD

FBC1

12

2IFIN

11

VSS

VDD

VSS

2.2 kΩ

200 µA

2.2 kΩ

The in-phase signal comes directly from the output of

the IF limiting amplifier to MIXER2. The quadrature

signal is created by an external tuned circuit from the

output of the IF limiting amplifier (2IFOUT, Pin 15) AC-

coupled to the MIXER2 DEMIN (Pin 16) input. The input

impedance of the DEMIN pin is approximately 47 kΩ.

FBC2

13

Vss

VSS

FIGURE 2-8: BLOCK DIAGRAM OF IF

LIMITING AMPLIFIER OUTPUT

The external tuned circuit can be constructed from sim-

ple inductor-capacitor (LC) components but will require

one of the elements to be tunable. A no-tune solution

can be constructed with a ceramic discriminator.

VDD

The output voltage of the DEMOD amplifier (DEMout+

and DEMout-, Pins 23 and 24) depends on the peak

deviation of the FSK or FM signal and the Q of the

external tuned circuit. DEMout+ and DEMout- are high

impedance outputs with only a 20 µA current capability.

2IFOUT

15

40 µA

VSS

The Demodulator pins are illustrated in Figures 2-10

and 2-11.

2.5.2

RECEIVED SIGNAL STRENGTH

INDICATOR (RSSI)

FIGURE 2-10: BLOCK DIAGRAM OF

DEMODULATOR INPUT PIN

The RSSI signal is proportional to the log of the signal

at 2IFIN. The 2IFIN input RSSI range is approximately

40 µV to 160 mV. The slope of the RSSI output is

approximately 26 mV/dB of RF signal.

VDD

47 kΩ

DEMIN

16

The RSSI output has an internal 36 kΩ resister to Vss

fed by a current source. This resistor converts the

RSSI current to voltage.

VSS

For Amplitude Shift Keying (ASK) demodulation, RSSI

is compared to a reference voltage (static or dynamic).

Post detector filtering is easily implemented by

connecting a capacitor to ground from the RSSI pin

effectively creating an RC filter with the internal 36 kΩ

resistor.

 2003 Microchip Technology Inc.

Preliminary

DS70090A-page 7

rfRXD0420/0920

FIGURE 2-11: BLOCK DIAGRAM OF

DEMODULATOR OUTPTUT

PINS

VDD

50 Ω

DEMOUT+

23

20 µA

VSS

20 µA

VSS

VDD

50 Ω

20 µA

VSS

DEMOUT-

24

20 µA

VSS

2.7

Operational Amplifier

The internal operational amplifier (OPA) can be

configured as a comparator for ASK or FSK or as a filter

for FM modulation applications.

The Op Amp pins are illustrated in Figures 2-12 and

2-13.

FIGURE 2-12: BLOCK DIAGRAM OF OP AMP

INPUT PINS

VDD

20 µA

50 Ω

OPA-

19

OPA+

20

VSS

FIGURE 2-13: BLOCK DIAGRAM OF OP AMP

OUTPUT PIN

VDD

50 Ω

OPA

18

VSS

DS70090A-page 8

Preliminary

 2003 Microchip Technology Inc.

rfRXD0420/0920

effect the trim capacitor has on the receive frequency

for the rfRXD0420 at 433.92 MHz. Keep in mind that

this graph represents one example circuit and the

actual results depends on the crystal and PCB layout.

3.0

APPLICATION CIRCUITS

This section provides general information on applica-

tion circuits for the rfRXD0420/0920 receiver. The

following connections and external components

provide starting points for designs and list the minimum

FIGURE 3-2: RECEIVE FREQUENCY VS.

TRIM CAPACITANCE

circuitry

recommended

for

general

purpose

applications.

434.10

434.05

434.00

433.95

433.90

433.85

433.80

433.75

Performance of the radio system (transmitter and

receiver) is affected by component selection and the

environment in which it operates. Each system design

has its own unique requirements. Specifications for a

particular design requires careful analysis of the appli-

cation and compromises for a practical implementation.

3.1

General

This subsection lists connections and components that

are common between applications. The following

subsections give specific circuit connections and

components for ASK, FSK and FM applications.

Trim Capacitor (pF)

Note that a 0 Ω resistor, in the lower left of the graph,

represents an infinite capacitance. This will be the

lowest frequency obtainable for the crystal and PCB

combination.

3.1.1 BYPASS CAPACITORS

Bypass capacitors should be placed as physically close

as possible to VDD pins 8, 14, 17, 27 and 32

respectively. Additional bypassing and board level low-

pass filtering of the power supply may be required

depending on the application.

Calculation of the crystal frequency requires knowl-

edge of the receive frequency (f ) and intermediate

rf

frequency (f ). Figure 3-3 is a worksheet to assist the

if

designer in calculating the crystal frequency. Table 3-1

lists crystal frequencies for popular receive frequen-

cies. Table 3-2 lists crystal parameters required for

ordering crystals. For background information on

crystal selection see Application Note AN826, Crystal

3.1.2 FREQUENCY PLANNING

The rfRXD0420/0920 receivers are single-conversion

TM

Oscillator Basics and Crystal Selection for rfPIC and

superheterodyne architecture with

frequency. The receive frequency is set by the crystal

frequency (f ) and intermediate frequency (f ). For

a

single IF

®

PICmicro Devices.

XTAL

if

TABLE 3-1: CRYSTAL FREQUENCIES FOR

POPULAR RECEIVE

a majority of applications an external crystal is

connected to XTAL (Pin 26). Figure 3-1 illustrates an

example circuit with an optional trim capacitor.

FREQUENCIES

Receive

Crystal

Frequency

FIGURE 3-1: XTAL EXAMPLE CIRCUIT

WITH OPTIONAL TRIM

Frequency

rfRXD0420

CAPACITOR

(2)

(1)

315 MHz

20.35625 MHz

26.45125 MHz

433.92 MHz

26

rfRXD0920

(1)

868.3 MHz

915 MHz

26.8 MHz

C TRIM

(1)

(OPTIONAL)

28.259375 MHz

(1) Low-side injection (2) High-side injection

X1

TABLE 3-2: CRYSTAL PARAMETERS

Parameter

Value

The crystal load capacitance should be specified to

include the internal load capacitance of the XTAL pin of

15 pF plus PCB stray capacitance (approximately 2 to

3 pF). A trim capacitor can be used to trim the crystal

on frequency within the limitations of the crystal’s trim

sensitivity and pullability. Figure 3-2 illustrates the

Frequency:

Mode:

(see Figure 3-1)

Fundamental

15-20 pF

Load Capacitance:

ESR:

60 Ω Maximum

These values are for design guidance only.

 2003 Microchip Technology Inc.

Preliminary

DS70090A-page 9

rfRXD0420/0920

FIGURE 3-3: FREQUENCY PLANNING WORKSHEET

Step 1: Identify receive (f ) and IF frequency (f ).

rf if

f

if

f

rf

f =

rf

____________________

f

lo

f

=

____________________

if

Step 2: Calculate crystal frequencies for high- and low-side injection:

f

x PLL divide ratio

XTAL

High-side Injection

(

f

rf

+

f

if

)

(

_________ + _________

)

f

=

= _______________

XTAL-HIGH

PLL divide ratio

16 if rfRXD0420

32 if rfRXD0920

Low-side Injection

(

f

rf

-

f

)

if

(

_________ - _________

)

f

=

= _______________

XTAL-LOW

PLL divide ratio

16 if rfRXD0420

32 if rfRXD0920

Step 3: Calculate Local Oscillator (LO) frequencies (f ) using f

lo

and f

:

XTAL-LOW

XTAL-HIGH

High-side Injection

16 if rfRXD0420

32 if rfRXD0920

f

=

f x PLL Divide Ratio

=

XTAL-HIGH

_________ x

= _____________

lo-HIGH

Low-side Injection

16 if rfRXD0420

32 if rfRXD0920

f

=

f

x PLL Divide Ratio

=

XTAL-LOW

_________ x

= _____________

lo-LOW

Step 4: Select high-side injection (f

) or low-side injection (f

lo-HIGH

) that corresponds to the LO frequency

lo-LOW

that is between the ranges of:

Device

LO Frequency Range

300 to 430 MHz

rfRXD0420

rfRXD0920

800 to 915 MHz

Step 5: From the chosen injection mode in Step 4, write the selected crystal frequency (f

) and circle

XTAL

injection mode.

(circle one)

f

=

____________________

High-side Injection

Low-side Injection

XTAL

Step 6: Calculate image frequency (f

) for the Injection mode chosen:

rf-image

if High-side Injection

f

=

f + (2 x f )

rf if

=

___________ + ( 2 x ___________ ) = ______________

rf-image

if Low-side Injection

f

=

f - (2 x f )

rf if

=

___________ - ( 2 x ___________ ) = ______________

rf-image

Note: Image frequency should be sufficiently filtered by the preselector for the application.

DS70090A-page 10

Preliminary

 2003 Microchip Technology Inc.

rfRXD0420/0920

The SAW filter has the added advantage of filtering

wide-band noise and improving the signal-to-noise

ratio (SNR) of the receiver.

3.1.3 PLL LOOP FILTER

An external PLL loop filter is connected to pin LF

(Pin 29). The loop filter controls the dynamic behavior

of the PLL, primarily lock time and spur levels. Gener-

ally, the PLL lock time is a small fraction of the overall

receiver start-up time (see Electrical Characteristics

Section). The crystal oscillator is the largest contributor

to start-up time. Thus, for the majority of applications,

design loop filter values for a wide loop bandwidth to

suppress noise. Figure 3-4 illustrates an example filter

circuit for a wide frequency range suitable for a majority

of applications.

SAW filters require impedance matching. Refer to the

manufacturers' data sheet and application notes for

SAW filter pinouts, specified impedances and recom-

mended matching circuits. Figure 3-5 shows a SAW

filter example circuit.

A secondary purpose of the preselector is to provide

impedance matching between the antenna and LNAIN

(Pin 31).

3.1.5 ANTENNA

FIGURE 3-4: PLL LOOP FILTER EXAMPLE

CIRCUIT

Receiver performance and device packaging influence

antenna selection. There are many third-party anten-

nas to choose from. Third-party antennas typically

have an impedance of 50 Ω. The preselector compo-

nents should be chosen to match the impedance of the

antenna to the LNAIN (Pin 31) impedance of

26 Ω || 2 pF.

29

C2

OPTIONAL

C1

1000 pF

The designer can chose to use a simple wire antenna.

The length of the wire should be one-quarter the wave-

length (λ) of the receive frequency. For example, the

wavelength of 433.92 MHz is:

R1

10 kΩ

8

λ = c / f where c = 3 x 10 m/s

rf

8 6

λ = 3 x 10 m/s / 433.92 x 10 Hz

3.1.4 PRESELECTOR

λ = 0.69 m

therefore

Receiver performance is heavily influenced by the

preselector (also known as the front-end filter). The

purpose of the preselector is to filter unwanted signals

and noise from entering the receiver.

0.25λ = 17.3 cm or 6.8 inches

Finally, the wire antenna should be impedance

matched to the preselector. The typical impedance of a

one-quarter wavelength wire antenna is 36 Ω.

The most important unwanted signal is the image

frequency (f

). Pay particular attention to the

rf-image

image frequency calculated in Figure 3-3 as this will be

the frequency that needs to be filtered out by the

preselector.

3.1.6 LNA GAIN

For a majority of applications, LNAGAIN can be tied to

Vss (ground) enabling High Gain mode. If the applica-

tion requires short range communications, LNAGAIN

can be tied to VDD (pulled up) enabling Low Gain mode.

The preselector can be designed using a simple LC

filter or a Surface Acoustic Wave (SAW) filter. A simple

LC filter provides a low cost solution but will have the

least effect filtering the image frequency. A SAW filter

can effectively filter the image frequency with a

minimum of 40 dB attenuation.

More Information on LNAGAIN operation can be found

in the Circuit Description section.

FIGURE 3-5: SAW FILTER EXAMPLE CIRCUIT

F1

Input

SAW Filter

Output

L1

L2

2

5

6

Antenna

LNAIN

1

Input Gnd Output Gnd

Case Gnd

C1

C2

3

4

7

8

Note: Refer to SAW filter manufacturer’s data sheet for pin outs

and values for impedance matching components.

 2003 Microchip Technology Inc.

Preliminary

DS70090A-page 11

rfRXD0420/0920

3.1.7 LNA TUNED CIRCUIT

3.1.8 MIXER1 BIAS

The LNAOUT (Pin 3) has an open-collector output. It is

pulled up to VDD via a tuned circuit. It is also connected

to 1IFIN (Pin 4) via a series decoupling capacitor. The

1IFIN input impedance is approximately 33 Ω || 1.5 pF.

The 1IF+ (Pin 6) and 1IF- (Pin 7) are bias connections

to the MIXER1 balanced collectors. Both pins are

open-collector outputs and are individually pulled up to

VDD by a load resistor. Figure 3-7 shows a MIXER1

bias example circuit.

Important: To ensure LNA stability the VSS pin (Pin 1)

must be connected to a low impedance ground.

FIGURE 3-7: MIXER1 BIAS EXAMPLE

CIRCUIT

As shown in Figure 3-6, components C1 and L1 make

up the tuned circuit and provide collector current via

pull-up. Together with decoupling capacitor C2, they

provided impedance matching between the LNA and

MIXER1. To a lesser extent, C1, L1, and C2 provide

VDD

band-pass filtering at the receive frequency (f ).

rf

R1

470 Ω

R2

470 Ω

Component values depend on the selected receive

frequency. The challenge is to design the circuit with

the fewest components setting Q as high as possible

as limited by component tolerances. For a majority of

applications it is best to design a wide bandwidth tuned

circuit to account for manufacturing and component

tolerances. The best approach is to design the tuned

circuit using a filter simulation program. Table 3-3 lists

example component values for popular receive

frequencies.

6

7

3.1.9 INTERMEDIATE FREQUENCY (IF)

FILTER

The IF filter defines the overall adjacent signal selectiv-

ity of the receiver. For a majority of applications, low-

cost 10.7 MHz ceramic IF filters are used. These are

available in a variety of bandwidths and packages.

FIGURE 3-6: LNA OUTPUT TO MIXER1

EXAMPLE CIRCUIT.

IF filter bandwidth selection is a function of:

• modulation (ASK, FSK or FM)

• signal bandwidth

VDD

• frequency and temperature tolerances of the

transmitter and receiver components

C Bypass

The typical input and output impedance of ceramic

filters is 330 Ω. 1IFOUT (Pin 9) has an approximately

330 Ω single-ended output impedance and provides a

direct match to the ceramic IF filter. The internal resis-

tance of the 2IFIN (Pin 11) is approximately 2.2 kΩ. In

order to terminate ceramic IF filters a 390 Ω resistor

can be paralleled to the 2IFIN and FBC2 (Pin 13).

Figure 3-8 shows an example circuit schematic using a

10.7 MHz ceramic IF filter.

C1

L1

C2

3

4

3.1.10 IF LIMITING AMPLIFIER EXTERNAL

FEEDBACK CAPACITORS

TABLE 3-3: LNA TUNED CIRCUIT EXAMPLE

COMPONENT VALUES

FBC1 (Pin 12) and FBC2 (Pin 13) are connected to

external feedback capacitors. Figure 3-8 shows

component values and connections for these

capacitors.

f

rf

C1

L1

C2

315 MHz

433.92 MHz

868.3 MHz

915 MHz

7.0 pF

3.0 pF

2.0 pF

22 nH

15 nH

7.6 nH

6.8 nH

6.0 pF

3.0 pF

These values are for design guidance only.

DS70090A-page 12

Preliminary

 2003 Microchip Technology Inc.

rfRXD0420/0920

FIGURE 3-8: IF FILTER, LIMITING AMPLIFIER AND DEMODULATOR BLOCK DIAGRAM

I N

D E M

2 I F

O U T

 2003 Microchip Technology Inc.

Preliminary

DS70090A-page 13

rfRXD0420/0920

FIGURE 3-9: ASK APPLICATION CIRCUIT

O P A

D D V

S S V

M I X E R 2

O U T + D E M

O U T - D E M

I N

D E M

O U T 2 I F

D D V

1 0 0 0 p F

C 1 3

F B C 2

S S V

F B C 1

X T A L

I N 2 I F

S S V

D D V

O U T 1 I F

E N R X

L F

D D V

1 I F -

1 I F +

S S V

1 I F

I N

O U T L N A

G A I N L N A

S S V

DS70090A-page 14

Preliminary

 2003 Microchip Technology Inc.

rfRXD0420/0920

If the bit decision occurs near the end of the signal

period, then the time constant should be set at less

than or equal to the signal period. Figure 3-11

illustrates this method.

3.2

Amplitude Shift Keying (ASK)

Figure 3-9 illustrates an example ASK applications cir-

cuit.

The IF Limiting Amplifier with RSSI is used as an ASK

detector. The RSSI signal is post detector filtered and

then compared to a reference voltage to determine if

the incoming RF signal is a logical one or zero. The

reference voltage can be configured as a dynamic

voltage level determined by the incoming RF signal

strength or by a predetermined fixed level.

Once the signal decision time and time period of the

signal period are known, then capacitor C1 can be

selected. Once C1 is selected, the designer should

observe the RSSI signal with an oscilloscope and

perform operational and/or bit error rate testing to

confirm receiver performance.

FIGURE 3-11: NEAR END OF THE SIGNAL

PERIOD DECISION RSSI LOW-

PASS FILTERED

3.2.1 RSSI POST DETECTOR FILTERING

The RSSI signal is low-passed filtered to remove high

frequency and pulse noise to aid the decision making

process of the comparator and increase the sensitivity

of the receiver. The RSSI signal low-pass filter is a RC

filter created by the RSSI output impedance of 36 kΩ

and capacitor C1. Setting the time constant (RC = τ) of

the RC filter depends on the signal period and when the

signal decision will be made.

Signal Decision

OOK Signal

Signal Period

3.2.1.1

Signal Period

Optimum sensitivity of the receiver with reasonable

pulse distortion occurs when the RC filter time constant

is between 1 and 2 times the signal period. If the time

constant of the RC filter is set too short, there is little

noise filtering benefit. However, if the time constant of

the RC filter is set too long, the data pulses will become

elongated causing inter-symbol interference.

RSSI Signal

1τ to 2τ

3.2.2 COMPARATOR

3.2.1.2 Signal Decision

The internal operational amplifier is configured as a

comparator. The RSSI signal is applied to OPA+ (Pin

20) and compared with a reference voltage on OPA-

(Pin 19) to determine the logic level of the received

signal. The reference voltage can be dynamic or static.

If the bit decision occurs in the center of the signal

period (such as KEELOQ decoders), then one or two

times the RC filter time constant should be set at less

than or equal to half the signal period. Figure 3-10 illus-

trates this method. The top trace represents the

received on-off keying (OOK) signal. The bottom trace

shows the RSSI signal after the RC low-pass filter.

The choice of dynamic versus static reference voltage

depends in part on the ratio of logical ones versus

zeros of the data (this can also be thought of as the AC

content of the data). Provided the ratio has an even

number of logical ones versus zeros, a dynamic refer-

ence voltage can be generated with a simple low-pass

filter. The advantage of the dynamic reference voltage

is the increased receiver sensitivity compared to a fixed

reference voltage. However, the comparator will output

random data. The decoder (for example, a pro-

grammed PICmicro MCU or KEELOQ decoder) must

distinguish between random noise and valid data.

FIGURE 3-10: CENTER SIGNAL PERIOD

DECISION RSSI LOW-PASS

FILTERED

Signal Decision

OOK Signal

The choice of a static reference voltage depends in part

on the DC content of the data. That is, the data has an

uneven number of logical ones versus zeros. The

disadvantage of the static reference voltage is

decreased receiver sensitivity compared to a dynamic

reference voltage. In this case, the comparator will

output data without random noise.

Signal Period

RSSI Signal

1τ to 2τ

 2003 Microchip Technology Inc.

Preliminary

DS70090A-page 15

rfRXD0420/0920

Selection of component values for R1 and C2 is an

iterative process. First start with a time constant

between 10 to 100 times the signal rate. Second, view

the reference voltage against the RSSI signal to

determine if the values are suitable. Figure 3-12 is an

oscilloscope screen capture of an incoming RF square

wave modulated signal (ASK on-off keying). The top

trace is the data output of OPA (Pin 18). The two

bottom traces are the RSSI signal (Pin 21, bottom

square wave) and generated reference voltage (Pin 19,

bottom trace centered in the RSSI square wave). The

goal is to select values for R1 and C2 such that the

reference voltage is in the middle of the RSSI signal.

This reference voltage level provides the optimum data

comparison of the incoming data signal.

3.2.2.1 DYNAMIC REFERENCE VOLTAGE

A dynamic reference voltage can be derived by averag-

ing the received signal with a low-pass filter. The exam-

ple ASK application circuit shown in Figure 3-9, the

low-pass filter is formed by R1 and C2. The output of

the low-pass filter is then fed to OPA-.

The setting of the R1-C2 time constant depends on the

ratio of logical ones versus zeros and a trade off in

stability versus receiver reaction time. If the received

signal has an even number of logical ones versus

zeros, the time constant can be set relatively short.

Thus the reference voltage can react quickly to

changes in the received signal amplitude and differ-

ences in transmitters. However, it may not be as stable

and can fluctuate with the ratio of logical ones and

zeros. If the time constant is set long, the reference

voltage will be more stable. However, the receiver

cannot react as quickly upon the reception of a

received signal.

3.2.2.2 STATIC REFERENCE VOLTAGE

A static reference voltage can be derived by a voltage

divider network.

FIGURE 3-12:

RSSI AND REFERENCE VOLTAGE COMPARISON

OPA

(Pin 18)

RSSI

(Pin 21)

OPA-

(Pin 19)

DS70090A-page 16

Preliminary

 2003 Microchip Technology Inc.

rfRXD0420/0920

FIGURE 3-13: FSK APPLICATION CIRCUIT

O P A

D D V

S S V

M I X E R 2

O U T + D E M

O U T - D E M

I N

D E M

O U T 2 I F

D D V

1 0 0 0 p F

C 1 3

F B C 2

S S V

F B C 1

X T A L

I N 2 I F

S S V

D D V

O U T 1 I F

E N R X

L F

D D V

1 I F -

1 I F +

S S V

1 I F

I N

O U T L N A

G A I N L N A

S S V

 2003 Microchip Technology Inc.

Preliminary

DS70090A-page 17

rfRXD0420/0920

FIGURE 3-14: LC DISCRIMINATOR

EXAMPLE CIRCUIT

3.3

Frequency Shift Keying (FSK)

Figure 3-13 illustrates an example FSK application

circuit.

R1

4.7 kΩ

3.3.1 IF FILTER CONSIDERATIONS

C3

0-56 pF

As mentioned in the Section 3.1 above, IF filter band-

width selection is a function of:

• modulation (ASK, FSK or FM)

• signal bandwidth

C1

L1

1.0 pF

3.3 µH

• frequency and temperature tolerances of the

transmitter and receiver components

C2

680 pF

The occupied bandwidth of binary FSK signals is 2

times the peak frequency deviation plus 2 times the

signal bandwidth. For example, if the data rate is 2400

bits per second Manchester encoded, the signal band-

width is 4800 baud or 1200 Hz, and if the peak

frequency deviation is 24 kHz, the minimum bandwidth

of the IF filter is:

15

16

3.3.2.2 Ceramic Discriminator

A no-tune solution can be constructed with a ceramic

discriminator. Figure 3-15 illustrates an example

ceramic discriminator circuit.

IF BW

= (2 x 2400) + (2 x 24000)

= 52800 Hz

min

The ceramic discriminator acts as a parallel tuned

circuit at the IF frequency (for example, 10.7 MHz). The

parallel capacitor C3 tunes the ceramic resonator. The

high Q of this circuit enables higher output of the detec-

tor for small frequency deviations. However, smaller

frequency deviations require better frequency

tolerances at the transmitter and receiver.

Add to this value the frequency and temperature

tolerances of the transmitter and receiver components.

FSK signals are more sensitive to group delay varia-

tions of the IF filter. Therefore, a filter with a low group

delay variation should be used. As an alternative, a

filter with wider than required bandwidth can be used

because the group delay variation in the center of the

bandpass will be relatively constant.

In order to detect wider deviation or off-frequency

signals, the detector bandwidth has to be increased.

This can be accomplished by reducing the Q of the

tuned circuit. One method is to parallel a resistor

across the ceramic discriminator. A second is to

increase the value of the coupling capacitor C1

increasing the load on the detector. The result of

reducing the Q of the discriminator will be that the

detector output will be smaller.

3.3.2 FSK DETECTOR

The demodulator (DEMOD) section consists of a phase

detector (MIXER2) and amplifier creating a quadrature

detector (also known as a phase coincidence detector)

to demodulate the IF signal in FSK and FM modulation

applications. The in-phase signal comes directly from

the output of the IF limiting amplifier to MIXER2. The

quadrature signal is created by an external tuned circuit

from the output of the IF limiting amplifier (2IFOUT, Pin

15) AC-coupled to the MIXER2 DEMIN (Pin 16) input.

FIGURE 3-15: CERAMIC DISCRIMINATOR

EXAMPLE CIRCUIT

F1

3.3.2.1 LC Discriminator

CERAMIC DISCRIMINATOR

The external tuned circuit can be constructed from

simple inductor-capacitor (LC) components. This type

circuit produces and excellent output. However, one of

the elements (L or C) must be tunable. Figure 3-14

illustrates an example LC discriminator circuit using a

tunable capacitor. A similar circuit with a tunable induc-

tor is also possible. Resistor R1 = 4.7 kΩ reduces the

Q of the circuit so that frequency deviations of up to 75

kHz can be demodulated.

C1

1.0 pF

C3

10-12 pF

C2

680 pF

15

16

DS70090A-page 18

Preliminary

 2003 Microchip Technology Inc.

rfRXD0420/0920

3.3.3 POST DETECTOR FILTERING

Care should be taken in selecting the values of capac-

itors C1 and C2 (Figure 3-13) so that the output of the

detector is not distorted and receiver sensitivity

improved. These values are chosen depending on the

data signal rate.

Generally, if the data signal rate is fast then the filter

time constant can be set short. Conversely, if the signal

rate is slow, the filter time constant can be set long. The

designer should observe the output of the detector with

an oscilloscope and perform operational and/or bit

error rate testing to confirm receiver performance.

3.3.4 COMPARATOR

The output of the DEMOD amplifier (DEMOUT+ and

DEMOUT-, Pins 23 and 24) depends on the peak

deviation of the FSK or FM signal and the Q of the

external tuned circuit. DEMout+ and DEMout- are high

impedance outputs with only a 20 µA current capability.

The capacitance on these pins limit the maximum data

signal rate. The nominal output voltage of these pins is

1.23V.

 2003 Microchip Technology Inc.

Preliminary

DS70090A-page 19

rfRXD0420/0920

FIGURE 3-16: FM APPLICATION CIRCUIT

O P A

D D V

S S V

M I X E R 2

O U T + D E M

D E M

I N

-

O U T

D E M

O U T 2 I F

D D V

1 0 0 0 p F

C 1 3

F B C 2

F B C 1

S S V

X T A L

I N 2 I F

S S V

D D V

O U T 1 I F

E N R X

L F

D D V

1 I F -

1 I F +

S S V

1 I F

I N

O U T L N A

G A I N L N A

S S V

DS70090A-page 20

Preliminary

 2003 Microchip Technology Inc.

rfRXD0420/0920

3.4

Frequency Modulation (FM)

Figure 3-16 illustrates an example FM application

circuit.

3.4.1 FSK DETECTOR

FM demodulation is performed in the same manner as

described in the FSK section above.

3.4.2 OPERATIONAL AMPLIFIER

The internal operational amplifier is configured as an

active low-pass filter.

FM audio is typically de-emphasized. It is recom-

mended that de-emphasis circuitry be connected at the

output of the operational amplifier rather than the

output of the detector.

 2003 Microchip Technology Inc.

Preliminary

DS70090A-page 21

rfRXD0420/0920

4.0

ELECTRICAL CHARACTERISTICS

Absolute Maximum Ratings

Supply voltage...................................................................................................................................................0 to +7.0V

Input voltage...........................................................................................................................................-0.3 to VCC+0.3V

Input RF level.........................................................................................................................................................10dBm

Storage temperature .................................................................................................................................... -40 to +125C

† NOTICE: Stresses above 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 those or any other conditions above those

indicated in the operation listings of this specification is not implied. Exposure to maximum rating conditions for

extended periods may affect device reliability.

DS70090A-page 22

Preliminary

 2003 Microchip Technology Inc.

rfRXD0420/0920

4.1

DC Characteristics: rfRXD0420

(Industrial)

Standard Operating Conditions (unless otherwise stated)

DC CHARACTERISTICS

Operating Temperature -40°C ≤ TA ≤ +85°C

Param

Sym

No.

†

Characteristic

Supply Voltage

Min

Typ

Max

Units

Conditions

VCC

2.5

2.7

—

5.5

100

8.0

V

f < 400 MHz

rf

f > 400 MHz

rf

ISTBY

ICC

Standby Current

nA

mA

mV

nA

V

ENRX = 0

Supply Current

5.0

6.5

8.2

—

LNAGAIN = 1

LNAGAIN = 0

10.0

20

VOPA

IOPA

Op Amp input voltage offset

Op Amp input current offset

Op Amp input bias current

RSSI voltage

-20

-50

—

50

IBIAS

VRSSI

-100

0.5

100

1.5

1.0

1.9

LNAGAIN = 1

LNAGAIN = 0

1.25

2.45

V

*

These parameters are characterized but not tested.

†

Data in “Typ” column is at 3V, 23°C unless otherwise stated. These parameters are for design guidance only and

are not tested.

4.2

AC Characteristics: rfRXD0420

(Industrial)

Standard Operating Conditions (unless otherwise stated)

AC CHARACTERISTICS

Operating Temperature -40°C ≤ TA ≤ +85°C

Param

Sym

No.

†

Characteristic

Min

Typ

Max

Units

Conditions

TFSK

TASK

Start-up time - FSK/FM

Start-up time - ASK

0.9

ms

ENRX = 0 to 1

R1xC1

Note 1

+TFSK

Sensitivity - Narrowband FSK

Sensitivity - Wideband FSK

Sensitivity - Narrowband ASK

Sensitivity - Wideband ASK

-111

-104

-109

-106

0

dBm

Note 2

Note 3

Note 4

Note 5

Input RF level maximum FSK/

FM

LNAGAIN = 1

Input RF level maximum ASK

-10

dBm

LNAGAIN = 1

*

These parameters are characterized but not tested.

†

Data in “Typ” column is at 3V, 23°C, f = 433.6 MHz, IF = 10.7 MHz unless otherwise stated. These parameters

rf

are for design guidance only and are not tested.

Note 1: Dependant on ASK detector time constant.

-3

2: IF bandwidth = 40 kHz, ∆f = +/- 15 kHz, BER <= 3 x 10

-3

3: IF bandwidth = 150 kHz, ∆f = +/- 50 kHz, BER <= 3 x 10

-3

4: IF bandwidth = 40 kHz, BER <= 3 x 10

-3

5: IF bandwidth = 150 kHz, BER <= 3 x 10

 2003 Microchip Technology Inc.

Preliminary

DS70090A-page 23

rfRXD0420/0920

4.3

DC Characteristics: rfRXD0920

(Industrial)

Standard Operating Conditions (unless otherwise stated)

DC CHARACTERISTICS

Operating Temperature -40°C ≤ TA ≤ +85°C

Param

Sym

No.

†

Characteristic

Supply Voltage

Min

Typ

Max

Units

Conditions

VCC

2.5

3.3

—

5.5

100

9.0

11.0

20

V

f < 900 MHz

rf

f > 900 MHz

rf

ISTBY

ICC

Standby Current

nA

mA

mV

nA

V

ENRX = 0

Supply Current

6.0

7.5

9.2

—

LNAGAIN = 1

LNAGAIN = 0

VOPA

IOPA

Op Amp input voltage offset

Op Amp input current offset

Op Amp input bias current

RSSI voltage

-20

-50

—

50

IBIAS

VRSSI

-100

0.5

100

1.5

2.45

1.0

1.9

LNAGAIN = 1

LNAGAIN = 0

1.25

V

*

These parameters are characterized but not tested.

†

Data in “Typ” column is at 3V, 23°C unless otherwise stated. These parameters are for design guidance only and

are not tested.

4.4

AC Characteristics: rfRXD0920

(Industrial)

Standard Operating Conditions (unless otherwise stated)

AC CHARACTERISTICS

Operating Temperature -40°C ≤ TA ≤ +85°C

Param

Sym

No.

†

Typ

Characteristic

Min

Max

Units

Conditions

TFSK

TASK

Start-up time - FSK/FM

Start-up time - ASK

0.9

ms

ENRX = 0 to 1

R1xC1

Note 1

+ TFSK

Sensitivity - Narrowband FSK

Sensitivity - Wideband FSK

Sensitivity - Narrowband ASK

Sensitivity - Wideband ASK

-109

-102

-108

-104

0

dBm

Note 2

Note 3

Note 4

Note 5

Input RF level maximum FSK/

FM

LNAGAIN = 1

Input RF level maximum ASK

-10

dBm

LNAGAIN = 1

*

These parameters are characterized but not tested.

†

Data in “Typ” column is at 3V, 23°C, f = 433.6 MHz, IF = 10.7 MHz unless otherwise stated. These parameters

rf

are for design guidance only and are not tested.

Note 1: Dependant on ASK detector time constant.

-3

2: IF bandwidth = 40 kHz, ∆f = +/- 15 kHz, BER <= 3 x 10

-3

3: IF bandwidth = 150 kHz, ∆f = +/- 50 kHz, BER <= 3 x 10

-3

4: IF bandwidth = 40 kHz, BER <= 3 x 10

-3

5: IF bandwidth = 150 kHz, BER <= 3 x 10

DS70090A-page 24

Preliminary

 2003 Microchip Technology Inc.

rfRXD0420/0920

5.0 PACKAGING INFORMATION

5.1

Package Marking Information

32-Lead LQFP

Example

XXXXXXXXXXXX

YYWWNNN

rfRXD0420

02123ABC

Legend: XX...X Customer specific information*

Y

Year code (last digit of calendar year)

YY

Year code (last 2 digits of calendar year)

Week code (week of January 1 is week ‘01’)

Alphanumeric traceability code

WW

NNN

Note: In the event the full Microchip part number cannot be marked on one line, it will

be carried over to the next line thus limiting the number of available characters

for customer specific information.

*

Standard PICmicro device marking consists of Microchip part number, year code, week code, and

traceability code. For PICmicro device marking beyond this, certain price adders apply. Please check

with your Microchip Sales Office. For QTP devices, any special marking adders are included in QTP

price.

 2003 Microchip Technology Inc.

Preliminary

DS70090A-page 25

rfRXD0420/0920

5.2

Package Details

The following section gives the technical details of the package.

32-Lead Plastic Low Profile Quad Flat Package (LQ) 7 x 7 x 1.4 mm Body

Not available at this time.

DS70090A-page 26

Preliminary

 2003 Microchip Technology Inc.

rfRXD0420/0920

ON-LINE SUPPORT

SYSTEMS INFORMATION AND

UPGRADE HOT LINE

Microchip provides on-line support on the Microchip

World Wide Web site.

The Systems Information and Upgrade Line provides

system users a listing of the latest versions of all of

Microchip's development systems software products.

Plus, this line provides information on how customers

can receive the most current upgrade kits.The Hot Line

Numbers are:

The web site is used by Microchip as a means to make

files and information easily available to customers. To

view the site, the user must have access to the Internet

®

and a web browser, such as Netscape or Microsoft

®

Internet Explorer. Files are also available for FTP

download from our FTP site.

1-800-755-2345 for U.S. and most of Canada, and

1-480-792-7302 for the rest of the world.

ConnectingtotheMicrochipInternetWebSite

The Microchip web site is available at the following

URL:

092002

www.microchip.com

The file transfer site is available by using an FTP

service to connect to:

ftp://ftp.microchip.com

The web site and file transfer site provide a variety of

services. Users may download files for the latest

Development Tools, Data Sheets, Application Notes,

User's Guides, Articles and Sample Programs. A vari-

ety of Microchip specific business information is also

available, including listings of Microchip sales offices,

distributors and factory representatives. Other data

available for consideration is:

• Latest Microchip Press Releases

• Technical Support Section with Frequently Asked

Questions

• Design Tips

• Device Errata

• Job Postings

• Microchip Consultant Program Member Listing

• Links to other useful web sites related to

Microchip Products

• Conferences for products, Development Systems,

technical information and more

• Listing of seminars and events

 2003 Microchip Technology Inc.

Preliminary

DS70090A-page 27

rfRXD0420/0920

READER RESPONSE

It is our intention to provide you with the best documentation possible to ensure successful use of your Microchip prod-

uct. If you wish to provide your comments on organization, clarity, subject matter, and ways in which our documentation

can better serve you, please FAX your comments to the Technical Publications Manager at (480) 792-4150.

Please list the following information, and use this outline to provide us with your comments about this document.

To:

Technical Publications Manager

Reader Response

Total Pages Sent ________

RE:

From:

Name

Company

Address

City / State / ZIP / Country

Telephone: (_______) _________ - _________

FAX: (______) _________ - _________

Application (optional):

Would you like a reply?

Y

N

Literature Number:

DS70090A

Device:

rfRXD0420/0920

Questions:

1. What are the best features of this document?

2. How does this document meet your hardware and software development needs?

3. Do you find the organization of this document easy to follow? If not, why?

4. What additions to the document do you think would enhance the structure and subject?

5. What deletions from the document could be made without affecting the overall usefulness?

6. Is there any incorrect or misleading information (what and where)?

7. How would you improve this document?

DS70090A-page 28

Preliminary

 2003 Microchip Technology Inc.

rfRXD0420/0920

PRODUCT IDENTIFICATION SYSTEM

To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office.

PART NO.

Device

X

/XX

XXX

Examples:

Temperature Package

Range

Pattern

a)

b)

rfRXD0420-I/LQ = Industrial temp, LQFP

package

rfRXD0920-I/LQ = Industrial temp, LQFP

package

Device

rfRXD0420-I/LQ UHF ASK/FSK/FM Receiver

rfRXD0920-I/LQ UHF ASK/FSK/FM Receiver

rfRXD0420T-I/LQ UHF ASK/FSK/FM Receiver

(Tape & Reel)

rfRXD0920T-I/LQ UHF ASK/FSK/FM Receiver

(Tape & Reel)

Temperature Range

I

=

-40°C to +85°C

Package

LQ

LQFP32

Pattern

Special Requirements

Sales and Support

Data Sheets

Products supported by a preliminary Data Sheet may have an errata sheet describing minor operational differences and recom-

mended workarounds. To determine if an errata sheet exists for a particular device, please contact one of the following:

1. Your local Microchip sales office

2. The Microchip Corporate Literature Center U.S. FAX: (480) 792-7277

3. The Microchip Worldwide Site (www.microchip.com)

Please specify which device, revision of silicon and Data Sheet (include Literature #) you are using.

New Customer Notification System

Register on our web site (www.microchip.com/cn) to receive the most current information on our products.

 2003 Microchip Technology Inc.

Preliminary

DS70090A-page29

rfRXD0420/0920

NOTES:

DS70090A-page30

Preliminary

 2003 Microchip Technology Inc.

Note the following details of the code protection feature on Microchip devices:

•

Microchip products meet the specification contained in their particular Microchip Data Sheet.

Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the

intended manner and under normal conditions.

•

There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our

knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip's Data

Sheets. Most likely, the person doing so is engaged in theft of intellectual property.

•

Microchip is willing to work with the customer who is concerned about the integrity of their code.

Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not

mean that we are guaranteeing the product as “unbreakable.”

Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our

products. Attempts to break microchip’s code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts

allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act.

Information contained in this publication regarding device

applications and the like is intended through suggestion only

and may be superseded by updates. It is your responsibility to

ensure that your application meets with your specifications. No

representation or warranty is given and no liability is assumed by

Microchip Technology Incorporated with respect to the accuracy

or use of such information, or infringement of patents or other

intellectual property rights arising from such use or otherwise.

Use of Microchip’s products as critical components in life

support systems is not authorized except with express written

approval by Microchip. No licenses are conveyed, implicitly or

otherwise, under any intellectual property rights.

Trademarks

The Microchip name and logo, the Microchip logo, K^EELOQ,

MPLAB, PIC, PICmicro, PICSTART, PRO MATE and

PowerSmart are registered trademarks of Microchip Technology

Incorporated in the U.S.A. and other countries.

FilterLab, microID, MXDEV, MXLAB, PICMASTER, SEEVAL

and The Embedded Control Solutions Company are registered

trademarks of Microchip Technology Incorporated in the U.S.A.

Accuron, dsPIC, dsPICDEM.net, ECONOMONITOR,

FanSense, FlexROM, fuzzyLAB, In-Circuit Serial Programming,

ICSP, ICEPIC, microPort, Migratable Memory, MPASM, MPLIB,

MPLINK, MPSIM, PICC, PICkit, PICDEM, PICDEM.net,

PowerCal, PowerInfo, PowerTool, rfPIC, Select Mode,

SmartSensor, SmartShunt, SmartTel and Total Endurance are

trademarks of Microchip Technology Incorporated in the U.S.A.

and other countries.

Serialized Quick Turn Programming (SQTP) is a service mark of

Microchip Technology Incorporated in the U.S.A.

All other trademarks mentioned herein are property of their

respective companies.

Printed on recycled paper.

Microchip received QS-9000 quality system

certification for its worldwide headquarters,

design and wafer fabrication facilities in

Chandler and Tempe, Arizona in July 1999

and Mountain View, California in March 2002.

The Company’s quality system processes and

procedures are QS-9000 compliant for its

PICmicro^®8-bit MCUs, KEELOQ^®code hopping

devices, Serial EEPROMs, microperipherals,

non-volatile memory and analog products. In

addition, Microchip’s quality system for the

design and manufacture of development

systems is ISO 9001 certified.

 2003 Microchip Technology Inc.

Preliminary

DS70090A - page 31

WORLDWIDE SALES AND SERVICE

Japan

AMERICAS

ASIA/PACIFIC

Microchip Technology Japan K.K.

Corporate Office

Australia

Benex S-1 6F

2355 West Chandler Blvd.

Microchip Technology Australia Pty Ltd

Suite 22, 41 Rawson Street

Epping 2121, NSW

3-18-20, Shinyokohama

Chandler, AZ 85224-6199

Kohoku-Ku, Yokohama-shi

Kanagawa, 222-0033, Japan

Tel: 81-45-471- 6166 Fax: 81-45-471-6122

Tel: 480-792-7200 Fax: 480-792-7277

Technical Support: 480-792-7627

Web Address: http://www.microchip.com

Australia

Tel: 61-2-9868-6733 Fax: 61-2-9868-6755

Korea

China - Beijing

Rocky Mountain

Microchip Technology Korea

168-1, Youngbo Bldg. 3 Floor

Samsung-Dong, Kangnam-Ku

Seoul, Korea 135-882

Microchip Technology Consulting (Shanghai)

Co., Ltd., Beijing Liaison Office

Unit 915

2355 West Chandler Blvd.

Chandler, AZ 85224-6199

Tel: 480-792-7966 Fax: 480-792-4338

Bei Hai Wan Tai Bldg.

Tel: 82-2-554-7200 Fax: 82-2-558-5934

Atlanta

No. 6 Chaoyangmen Beidajie

Beijing, 100027, No. China

Tel: 86-10-85282100 Fax: 86-10-85282104

Singapore

3780 Mansell Road, Suite 130

Alpharetta, GA 30022

Microchip Technology Singapore Pte Ltd.

200 Middle Road

Tel: 770-640-0034 Fax: 770-640-0307

China - Chengdu

#07-02 Prime Centre

Boston

Microchip Technology Consulting (Shanghai)

Co., Ltd., Chengdu Liaison Office

Rm. 2401-2402, 24th Floor,

Singapore, 188980

2 Lan Drive, Suite 120

Westford, MA 01886

Tel: 978-692-3848 Fax: 978-692-3821

Tel: 65-6334-8870 Fax: 65-6334-8850

Taiwan

Ming Xing Financial Tower

Microchip Technology (Barbados) Inc.,

Taiwan Branch

No. 88 TIDU Street

Chicago

Chengdu 610016, China

333 Pierce Road, Suite 180

Itasca, IL 60143

11F-3, No. 207

Tel: 86-28-86766200 Fax: 86-28-86766599

Tung Hua North Road

Taipei, 105, Taiwan

China - Fuzhou

Tel: 630-285-0071 Fax: 630-285-0075

Microchip Technology Consulting (Shanghai)

Co., Ltd., Fuzhou Liaison Office

Unit 28F, World Trade Plaza

Tel: 886-2-2717-7175 Fax: 886-2-2545-0139

Dallas

4570 Westgrove Drive, Suite 160

Addison, TX 75001

EUROPE

No. 71 Wusi Road

Austria

Tel: 972-818-7423 Fax: 972-818-2924

Fuzhou 350001, China

Microchip Technology Austria GmbH

Durisolstrasse 2

Detroit

Tel: 86-591-7503506 Fax: 86-591-7503521

Tri-Atria Office Building

China - Hong Kong SAR

A-4600 Wels

32255 Northwestern Highway, Suite 190

Farmington Hills, MI 48334

Tel: 248-538-2250 Fax: 248-538-2260

Microchip Technology Hongkong Ltd.

Unit 901-6, Tower 2, Metroplaza

223 Hing Fong Road

Austria

Tel: 43-7242-2244-399

Fax: 43-7242-2244-393

Denmark

Kwai Fong, N.T., Hong Kong

Kokomo

Tel: 852-2401-1200 Fax: 852-2401-3431

2767 S. Albright Road

Kokomo, Indiana 46902

Tel: 765-864-8360 Fax: 765-864-8387

Microchip Technology Nordic ApS

Regus Business Centre

Lautrup hoj 1-3

China - Shanghai

Microchip Technology Consulting (Shanghai)

Co., Ltd.

Ballerup DK-2750 Denmark

Tel: 45 4420 9895 Fax: 45 4420 9910

Los Angeles

Room 701, Bldg. B

18201 Von Karman, Suite 1090

Irvine, CA 92612

Far East International Plaza

No. 317 Xian Xia Road

France

Microchip Technology SARL

Parc d’Activite du Moulin de Massy

43 Rue du Saule Trapu

Tel: 949-263-1888 Fax: 949-263-1338

Shanghai, 200051

San Jose

Tel: 86-21-6275-5700 Fax: 86-21-6275-5060

Microchip Technology Inc.

2107 North First Street, Suite 590

San Jose, CA 95131

China - Shenzhen

Batiment A - ler Etage

Microchip Technology Consulting (Shanghai)

Co., Ltd., Shenzhen Liaison Office

91300 Massy, France

Tel: 33-1-69-53-63-20 Fax: 33-1-69-30-90-79

Tel: 408-436-7950 Fax: 408-436-7955

Rm. 1812, 18/F, Building A, United Plaza

No. 5022 Binhe Road, Futian District

Shenzhen 518033, China

Germany

Toronto

Microchip Technology GmbH

Steinheilstrasse 10

6285 Northam Drive, Suite 108

Mississauga, Ontario L4V 1X5, Canada

Tel: 905-673-0699 Fax: 905-673-6509

Tel: 86-755-82901380 Fax: 86-755-82966626

D-85737 Ismaning, Germany

Tel: 49-89-627-144 0 Fax: 49-89-627-144-44

China - Qingdao

Rm. B503, Fullhope Plaza,

Italy

No. 12 Hong Kong Central Rd.

Qingdao 266071, China

Microchip Technology SRL

Centro Direzionale Colleoni

Palazzo Taurus 1 V. Le Colleoni 1

20041 Agrate Brianza

Tel: 86-532-5027355 Fax: 86-532-5027205

India

Milan, Italy

Microchip Technology Inc.

India Liaison Office

Tel: 39-039-65791-1 Fax: 39-039-6899883

Divyasree Chambers

United Kingdom

1 Floor, Wing A (A3/A4)

No. 11, O’Shaugnessey Road

Bangalore, 560 025, India

Tel: 91-80-2290061 Fax: 91-80-2290062

Microchip Ltd.

505 Eskdale Road

Winnersh Triangle

Wokingham

Berkshire, England RG41 5TU

Tel: 44 118 921 5869 Fax: 44-118 921-5820

12/05/02

DS70090A-page 32

Preliminary

 2003 Microchip Technology Inc.


型号：	RFRXD0920
厂家：	MICROCHIP
描述：	UHF ASK/FSK/FM Receiver 超高频ASK / FSK / FM接收器
文件：	总32页 (文件大小：632K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

RFRXD0920 [MICROCHIP]

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