LX3301AQPW [MICROSEMI]
Inductive Sensor Interface IC with Embedded MCU;
| 型号： | LX3301AQPW |
| 厂家： | 
Microsemi |
| 描述： | Inductive Sensor Interface IC with Embedded MCU |
| 文件： | 总21页 (文件大小：996K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
Preliminary Datasheet
LX3301A
Inductive Sensor Interface IC with Embedded MCU
Features
. Built-in Oscillator for Driving Primary Coil
Description
The LX3301A is a highly integrated programmable data
conversion IC designed for interfacing to and managing of
inductive sensors. The device includes an integrated
oscillator circuit for driving the primary coil of an inductive
sensor, along with two independent analog conversion
paths for conditioning, converting, and processing of sine
and cosine analog signals from the secondary coils of the
sensor. Each path includes an EMI filter, demodulator,
anti-alias filter, programmable amplifier, and a 13-bit
sigma-delta analog-to-digital converter.
. Two Independent Analog Channels With
Demodulation
. 32-Bit RISC MCU with 12k Bytes of
Program Memory
. 128 Bytes SRAM
. 32 Bytes EEPROM
. Two Programmable Gain Amplifiers
. Two Anti-alias Filters
. Two 13-bit ADCs
. Selection of SINC and FIR Digital Filters
. One 12-bit DAC
Each analog signal path includes digital calibration
capability which allows the complete analog path (including
the external sensors) to be calibrated during the system
manufacturing process. The calibration information is
written to internal EEPROM resulting in improved
production yields, and in-line system upgrades.
. One 16-bit PWM
. Multiple Faults Detection and Protection
. Reverse Power Protection
. Digital Calibration with Non-volatile
Configuration Storage (EEPROM)
The LX3301A integrates a 32-bit RISC processor which
provides programmable digital filtering and signal
processing functions. The MCU resources include 12 kilo
bytes of program memory, 128 bytes of SRAM, and 32
bytes of user programmable EEPROM. The program
memory is available as mask-programmed ROM.
. Protected Watchdog Timer
. Low Temperature Drift
. -40°C to 125°C Operation
. TD, PWM(push-pull), PWM (OD) Output
. Excellent Long Term Stability
. AEC-Q100 Certification
System interfaces include programmable PWM output and
a 12-bit digital-to-analog converter analog buffed output.
. ISO26262 Compliant
The LX3301A is offered in TSSOP14, the device is
specified over a temperature range of -40°C to +125°C
making it suitable for a wide range of commercial,
industrial, medical, and/or automotive sensor applications.
Applications
. Automotive Control
. Medical Equipment
. ATE Equipment
. Industrial Process Control
. Smart Energy Saving Control
July 2015 Rev. 0.1
www.microsemi.com
© 2015 Microsemi Corporation- Analog Mixed Signal
1
LX3301A Inductive Sensor Interface IC with Embedded MCU
Typical Application
Power from Host
System
VIN
OSC1
OSC2
CL1
DOUT
AOUT
Host
System
LX3301A
GNDCL
CL2
EEWR
VDD
GND
Figure 1 · Typical Application System Diagram: LX3301AQPW
Block Diagram
Clock/
Watchdog
LDO
EEPROM
ROM
OSC1
OSC
OSC2
TD or PWM
(OD)
DOUT
AOUT
TD or PWM
(PP)
EMI
Filter
CL1
Demod
AAF
AAF
ADC
ADC
Filter
Filter
32-Bit
MCU
GNDCL
DAC
EMI
Filter
Demod
CL2
SUB
SRAM
Figure 2 · LX3301A Block Diagram
2
LX3301A Rev. 0.1
Pin Configuration
Pin Configuration
1
2
3
14
13
12
GND
SUB
DOUT
OSC1
OSC2
AOUT
VIN
VDD
NC
4
5
6
11
10
9
EEWR
CL2
GNDCL
CL1
8
7
NC
14-Pin TSSOP
Figure 3 · Pinout (Top View)
Matte Tin Lead Finish / MSL 1
YYWWA = Year/ Week/Lot Code
Ordering Information
Ambient
Type
Package
Part Number
Packaging Type
Temperature
LX3301AQPW
Bulk / Tube
RoHS2 compliant,
-40°C to 125°C
Pb-free
14-TSSOP
LX3301AQPW-TR
Tape and Reel
Thermal Data
Parameter
Value
103.7
Units
Thermal Resistance-Junction to Ambient, θJA
°C/W
Note: The JA numbers assume no forced airflow. Junction Temperature is calculated using TJ = TA + (PD x JA). In
particular, θJA is a function of the PCB construction. The stated number above is for a four-layer board in
accordance with JESD-51 (JEDEC).
LX3301A Rev. 0.1
3
LX3301A Inductive Sensor Interface IC with Embedded MCU
Pin Description
PIN#
Pin Designator
Description
Analog and digital power ground
1
GND
Digital Out. This pin can be programmed to Open-drain PWM with current
limit, or the threshold detector output.
2
3
DOUT
AOUT
Analog Out. This pin can be programmed to provide an analog output
(DAC), TD or a PWM output. PWM will be push-pull operation. This pin
can be used as address pin for EEMODE
Power supply and internal EEPROM program pin. DC input power is
applied to this pin for normal operation. Also used for EEPROM
programming (refer to application information). Bypass this pin to GND pin
with a low ESR capacitor of 100nF. Note that larger capacitance will affect
the EEPROM programming.
4
VIN
Regulator output. This is the output of the internal voltage regulator
providing power to the analog and digital blocks. Bypass this pin to GND
pin with a low ESR capacitor of not less than 1µF.
5
6
VDD
NC
NC
Reserved for factory testing. Connect it to GND
Reserved for factory testing. Connect it to GND
Sensor signal from secondary coil 1 of inductive sensor.
7
8
CL1
Reference ground for CL1 and CL2. Connect CL1 & CL2 coil to GNDCL
and connect the GNDCL to GND directly.
9
GNDCL
CL2
10
11
12
Sensor signal from secondary coil 2 of inductive sensor.
EEWR is active low. When EEWR is low, it prohibits change to the internal
EEPROM contents.
EEWR
OSC2
Oscillator pin 2. Connects to the second side of the primary inductor coil.
An external capacitor is connected between this pin and GND as part of
the LC tank circuit.
13
14
OSC1
SUB
Oscillator pin 1. Connects to the first side of the primary inductor coil. An
external capacitor is connected between this pin and GND to as part of the
LC tank circuit.
Substrate pin it is used for ground failure protection. It should not be
connected to GND, for normal application, leave this pin open
4
LX3301A Rev. 0.1
Absolute Maximum Ratings
Absolute Maximum Ratings
Parameter
Value
-7 to 20
-1 to 15
-0.3 to 16
-0.5 to 3.6
-0.5 to 16
0 to 95
-40 to 125
-40 to 150
300
Units
Supply Input Voltage (VIN)
V
mA
V
Load Current on VDD
Voltage on OSC1, OSC2
Voltage on CL1, CL2, EEWR
V
Voltage on AOUT, DOUT
V
Operating Humidity (non-condensing)
Operating Temperature
%
C
C
C
°C
kV
V
Storage Temperature
Lead Temperature (Soldering 10 seconds)
Package Peak Temp. for Solder Reflow (40 seconds exposure)
ESD, Human Body Model (HBM) AEC-Q100-002D
ESD, Charge Device Model (CDM) AEC-Q100-011
260
±2
750
Note: Stresses in excess of these absolute ratings may cause permanent damage. The device is not implied to be
functional under these conditions. All voltages are with respect to GND.
Recommended Operating Range
Parameter
Symbol
Test Condition
Min
Typ
Max
5.6
17
Units
Supply Voltage
VIN
For normal operating
4.4
5
V
V
EEPROM Program High VIN_PH
For normal operating, excluding
oscillator tail current
Supply Current
I_IN
10
mA
Output Current
Output Current
Output Current
IAOUT0
IAOUT5
IDOUT0
AOUT = 0V
AOUT = 5V
DOUT = 0V
-15
6
-8
15
mA
mA
mA
MHz
°C
28
Internal Clock Frequency FOSC
8.0
-40
8.2
8.4
125
Operating Temperature
TOP
LX3301A Rev. 0.1
5
LX3301A Inductive Sensor Interface IC with Embedded MCU
Electrical Characteristics
Unless otherwise defined, the following specifications apply over the operating temperature range of -40C ≤ TA ≤ 125°C,
and the following test conditions: VIN = 5V, VDD=3.5V, IDD=5mA, II/O=0mA – Typical values are at 25 °C.
Parameter
POWER
Symbol
Test Condition
Min
Typ
Max
Units
Supply Voltage
VIN
IIN
For normal operating
4.4
5
8
5.6
10
V
For normal operating , excluding
oscillator tail current ,IDD = 0mA,
II/O = 0mA, f = 8.2MHz
Supply Current
mA
VIN UVLO High Threshold VIN_UVLO_HI
4.1
3.6
4.3
4.1
V
V
VIN UVLO Low Threshold VIN_UVLO_LO AOUT goes low
3.75
3.5
VOLTAGE REFERENCE
Output Voltage
VDD UVLO
VDD
IDD = 10mA, Trimmed
Rising edge
3.45
2.9
3.55
3.4
V
V
VDD_UVLO
Additional current sourced to
external load(s)
Output Current
IDD
10
mA
OSCILLATOR
Middle Tap Voltage
VTAP
ITK
5
V
mA
Vpp
MHz
%
Total Tank DC Driving
Current
VTAP = 5V
VTAP = 5V
VTAP = 5V
VTAP = 5V
0
3
10
9.5
5
Swing Voltage of OSC1&2 VOSC
Reference Frequency
FOSC
1
Range
Frequency Variation
Reference Inductance
FOSCTOL
LOSC
-5
5
VTAP= 5V, Inductor connected to
OSC1,2 pins
6
µH
Tank Circuit Quality Factor QOSC
VTAP = 5V
15
25
Harmonics
HOSC
VTAP = 5V, GBNT
2
%
Resistance between OSC1
& VIN
VIN = 5V, OSC1 = GND, Measure
Current from OSC1 to GND
ROSC1_VIN
1
1
MΩ
Resistance between OSC2
& VIN
VIN = 5V, OSC2 = GND, Measure
Current from OSC2 to GND
ROSC2_VIN
ROSC1_GND
ROSC2_GND
MΩ
MΩ
MΩ
kΩ
Resistance between OSC1
& GND
VIN = 0V, OSC1 = 5V, Measure
Current from OSC1 to 5V
1
Resistance between OSC2
& GND
VIN = 0V, OSC2 = 5V, Measure
Current from OSC2 to 5V
1
Resistance Between
OSC1&OSC2
ROSC1&2_HI OSC1 = 1Vpp, OSC2 = GND
500
CL1 & CL2
Peak to Peak Sensor Signal Vpp_CL
VTAP = 5V,
GBNT
50
100
150
mV
EMI FILTER 1 & 2
Cut-off Frequency
EF01
13.5
MHz
DEMODULATOR AND FRONT-END AMPLIFIER 1, 2
Demodulator Gain
DAA01
DAA02
DAA03
GBNT
7
3.125
3
V/V
V/V
%
GBNT, Front End = 0000b to
1111b
Front-End Gain Range
2.375
3.781
Front End Gain Step
ANTI ALIAS FILTER 1 & 2
6
LX3301A Rev. 0.1
Electrical Characteristics
Parameter
Cut-off Frequency
Attenuation
ADC1 & 2
Symbol
AAF01
AAF02
Test Condition
GBNT
Min
Typ
24
Max
Units
kHz
GBNT
-60
dB/dec
ADC Resolution
Offset Drift
ADC01
ADC02
ADC03
ADC04
13
-5
-1
bits
mV
GBNT
GBNT
GBNT
0
5
1
8
Integral Non-Linearity
Absolute Offset Error
SINC, SINC+FIR Filter 1 & 2
Pass band
LSB
mV
PB00
REFRESH=00,(SINC,SINC+FIR)
REFRESH=01, (SINC,SINC+FIR)
REFRESH=10, (SINC,SINC+FIR)
REFRESH=11, (SINC,SINC+FIR)
REFRESH=00, FILTER=0
REFRESH=01, FILTER=0
REFRESH=10, FILTER=0
REFRESH=11, FILTER=0
REFRESH=00, FILTER=1
REFRESH=01, FILTER=1
REFRESH=10, FILTER=1
REFRESH=11, FILTER=1
Stop band
1
kHz
Hz
Pass band
PB01
500
250
125
2
Pass band
PB03
Hz
Pass band
PB04
Hz
Stop band
SB000
kHz
kHz
Hz
Stop band
SB001
1
Stop band
SB002
500
250
1.4
700
350
175
Stop band
SB003
Hz
Stop band
SB100
kHz
Hz
Stop band
SB101
Stop band
SB102
Hz
Stop band
SB103
Hz
Stop Band Attenuation
Delay
SBA
1
%
Delay000
Delay001
Delay002
Delay003
Delay100
Delay101
Delay102
Delay103
DUR00
DUR01
DUR02
DUR03
REFRESH=00, FILTER=0
REFRESH=01, FILTER=0
REFRESH=10, FILTER=0
REFRESH=11, FILTER=0
REFRESH=00, FILTER=1
REFRESH=01, FILTER=1
REFRESH=10, FILTER=1
REFRESH=11, FILTER=1
REFRESH=00,(SINC,SINC+FIR)
REFRESH=01, (SINC,SINC+FIR)
REFRESH=10, (SINC,SINC+FIR)
REFRESH=11, (SINC,SINC+FIR)
GBNT
0.25
0.5
1
ms
ms
ms
ms
ms
ms
ms
ms
kHz
kHz
Hz
Delay
Delay
Delay
2
Delay
0.5
1
Delay
Delay
2
Delay
4
Data Update Rate
Data Update Rate
Data Update Rate
Data Update Rate
2
1
500
250
-86
-44
-86
Hz
Filter SNR
FLTRSNR
CTR
-73
dB
Cross Talk Rejection
GBNT
dB
Power supply rejection ratio PSRR
GNBT
dB
Internal Clock
Clock Frequency
Processing Resources
MCU Data bus
FCLK
After Trimming
8
8.2
32
8.4
32
MHz
MCU01
MCU02
MCU03
MCU04
bit
bit
MCU Instruction size
ROM Size
16
32-bit words
12
KB
byte
SRAM Size
Application data, 32-bit words
128
LX3301A Rev. 0.1
7
LX3301A Inductive Sensor Interface IC with Embedded MCU
Parameter
Symbol
Test Condition
Min
Typ
Max
Units
cycles
words
EEPROM Write Endurance MCU05
10000
EEPROM Size
MCU06
(16-bit words)
16
Watchdog Timer
Timer for Power Up Self- test
(PUST)
Watchdog time, PUST
Watch dog time,
TPUST
TOP
16.3
10
ms
ms
Timer after completion PUST
Timer for EE Mode, after receiving
command and matching address
bits
Watchdog time, EEMode
TEE
100
ms
DOUT (PWM, OPEN DRAIN)
Refresh= 2kHz, after trimming,
25°C
Frequency
DOUT01
DOUT02
1.945
2
2.055
kHz
%
HCLMP=1023, LCLMP=0,
ORIGIN=0, frequency = 2kHz
Minimum PWM duty
0.125
Maximum PWM duty
PWM Jitter
DOUT03
DOUT04
DOUT05
No Clamped Output
100
28
%
0.2
%D
mA
Max Sink Current
DOUT = OD PWM, or TD
-27
2.0
AOUT ( AS ADDRESS SELECTION )
Hi-level Input Voltage
Low-level Input Voltage
AOUT ( ANALOG OUTPUT )
AOUT Analog Range
AOUT Low Voltage
AOUT_VIH
V
V
AOUT_VLO
0.3
AOUT_R
VAOUT_LO
VAOUT_HI
RL_AOUT
IAOUT0
0
VIN
4
V
RL_AOUT = 10kΩ to VIN
RL_AOUT = 10kΩ to GND
%VIN
%VIN
kΩ
AOUT High Voltage
AOUT Output load
96
1
10
AOUT Sink current
AOUT = 0V
AOUT = 5V
CLOAD = 22nF
CLOAD = 100nF
-15
6
-10
15
mA
AOUT Source Current
AOUT Slew Rate
IAOUT5
mA
AOUTSR1
AOUTSR2
VRatioErr
0.2
0.1
0
V/µs
V/µs
%VIN
%VIN
%VIN
%VIN
%VIN
AOUT Slew Rate
Ratiometric Error
-0.2
0.2
1
FAULT Output Low Level
FAULT Output Low Level
FAULT Output High Level
FAULT Output High Level
VAOUT_FL10K RL_AOUT = 10kΩ to VIN
VAOUT_FL1K RL_AOUT = 1kΩ to VIN
VAOUT_FH10K RL_AOUT = 10kΩ to GND
VAOUT_FH1K RL_AOUT = 1kΩ to GND
1.5
98
97
Ground Off Output low
Level
Broken GND, RL_AOUT ≤ 10kΩ
VAOUT_GF10K
to GND
4
1
%VIN
%VIN
%VIN
Ground Off Output High
Level
Broken GND, RL_AOUT ≥ 1kΩ to
VAOUT_GF1K
VIN
99
100
0
Broken VIN, RL_AOUT ≥ 1kΩ to
GND
VIN Open output Low Level VAO_VIN1K
AOUT (PWM Output)
Duty =50%, 10kΩ Pull-down to
GND
High level output voltage
VOH
95
0
100
200
%VIN
Low level output voltage
Rise time
VOL
Duty=50%, 10kΩ Pull Up to VIN
Duty=50%
mV
µs
AOUT_TR
AOUT_TF
10
10
Fall time
Duty=50%
µs
8
LX3301A Rev. 0.1
Electrical Characteristics
Parameter
Symbol
Test Condition
PWM(PP)
Min
Typ
Max
Units
%
Min Duty
Dmin_Aout
Dmax_Aout
IAOUTP
4
Max Duty
PWM(PP)
94
%
Max Drive/Sink Current
Output CLAMP
AOUT=PWM
-25
25
mA
Clamp High Output Level HCLMP
Clamp High Output Level LCLMP
EEPROM Programming
Pull Output up to VIN
Pull Output up to VIN
0
0
100
100
%VIN
%VIN
Program Low
Program Idle
Program High
Duration time
VIN_PL
VIN_PI
VIN_PH
td
For EEPROM programming mode
9.5
10
13
16
10.5
13.5
17
V
V
For EEPROM programming mode 11.75
For EEPROM programming mode 14.75
V
Duration time each voltage state
10
µs
LX3301A Rev. 0.1
9
LX3301A Inductive Sensor Interface IC with Embedded MCU
Configuration EEPROM
The LX3301A integrates a 16 Words X 16bits (256bits), user programmable EEPROM for storing calibration and
configuration parameters. The calibration parameters enable the production sensor assembly to be customer-factory
calibrated assuring consistent unit to unit performance. The following FIG1 shows LX3301AQPW EEPROM
configuration map and table 1 itemizes the LX3301A configuration EEPROM contents:
Name
Description
Size
(bit)
Word & Bits
(MSB:LSB)
Sign
Min
Value
Max
Value
Default
Value
ID
Customer Part ID
18
2
W0[15:0]W1[15:14]
W1[13:12]
No
No
No
0
0
3FFFF
3
REFRESH Refresh rate
0
FACTORY Microsemi Factory
programming
12
W1[11:0]
CHKSUM
S5
4bit checksum value
Slope of 6th segment
Output Set up
4
W2[15:12]
W2[11:0]
W3[15:12]
W3[11:0]
No
No
No
No
No
0
0
12
4
4095
511
1011B
511
OUTSEL
S0
Slope of 1st segment
12
12
0
0
4095
4095
ORIGIN
Origin
W4[15:12]W5[15:12]
W6[15:12]
0
Y5
X5
12
12
12
8
W4[11:0]
No
No
No
No
0
0
0
0
4095
4095
4095
255
3413
3413
2047
255
W5[11:0]
Y3
W6[11:0]
OSCOMP
OSC voltage
W7[15:12]W8[15:12]
Compensation
X3
Y1
12
12
1
W7[11:0]
W8[11:0]
W9[15]
No
No
No
No
0
0
0
0
4095
4095
1
2047
683
1
FILTER
TDHYST
Select digital filter
Threshold Detect
hysteresis
3
W9[14:12]
112
111B
X1
TD
12
12
W9[11:0]
No
No
0
0
4095
4095
683
Threshold Detect
W10[15:10]W11[15:
10]
3685
LCLMP
HCLMP
Y2
Low Clamp
10
10
6
W10[9:0]
W11[9:0]
W12[15:10]
W12[9:0]
W13[15:10]
W13[9:0]
W14[15:14]
W14[13]
No
No
0
0
1023
1023
31
511
31
511
3
0
High Clamp
1023
Y2 with Sign
Yes
Yes
Yes
Yes
No
-31
-511
-31
-511
0
0
0
0
0
0
0
0
0
0
DSIN
Dynamic Sine Offset
Y4 with Sign
10
6
Y4
SSIN
Static Sine Offset
Osc current Source
Debug
10
2
IOSC
DEBUG
TDPOL
CLSEL
EELOCK
1
No
0
1
TD Polarity
1
W14[12]
No
0
1
CL1,2 input select
1
W14[11]
No
0
1
EEPROM Write
Protection
1
W14[10]
No
0
1
DCOS
Dynamic Cosine
Offset correction
10
W14[9:0]
Yes
-511
511
0
GMTCH
SCOS
Gain Match
6
W15[15:10]
W15[9:0]
Yes
Yes
-12.09%
-511
12.09%
511
0
0
Static Cosine offset
Correction
10
Table 1 - LX3301AQPW Configuration EEPROM
10
LX3301A Rev. 0.1
Configuration EEPROM
MSB
LSB
LSB
MSB
15
15
14
14
13
13
12
12
11
11
10
10
9
9
8
8
7
7
6
6
5
5
4
4
3
3
2
2
1
1
0
0
WORD0
WORD0
ID[17..2
WORD1
WORD1
ID[1..0]
REFRESH
FACTORY[11..0]
S5[11..0]
S0[11..0]
Y5[11..0]
X5[11..0]
Y3[11..0]
X3[11..0]
Y1[11..0]
X1[11..0]
WORD2
WORD2
CHKSUM[3..0]
OUTSEL[3..0]
ORIGIN[11..8]
ORIGIN[7..4]
ORIGIN[3..0]
OSCOMP[7..4]
OSCOMP[3..0]
TDHYST[2..0]
TD[11..6
WORD3
WORD3
WORD4
WORD4
WORD5
WORD5
WORD6
WORD6
WORD7
WORD7
WORD8
WORD8
FILTER
WORD9
WORD9
WORD10
WORD10
LCLMP[9..0]
HCLMP[9..0]
DSIN[9..0]
SSIN[9..0]
WORD11
WORD11
TD[5..0]
WORD12
WORD12
Y2[5..0]
WORD13
WORD13
Y4[5..0]
EELOCK
TDPOL
WORD14
WORD14
IOSC[1..0] FMSK
CLSEL
DCOS[9..0]
SCOS[9:0]
WORD15
WORD15
GMTCH[5..0]
FIG. 1 - LX3301AQPW Configuration EEPROM MAP
ID
This is ID field. The Customer Part ID is a 18-bit field containing customer part identification information.
CHKSUM
This 4bit value is a 4bit CRC(cyclic redundancy check) to check the rest of content reliability through lifetime. The
CRC calculation is based on the following code:
#define GENPOLY 0x0013U /* x^4 + x + 1 */
uint32_t makecrc4(uint32_t b);
uint32_t makecrc4(uint32_t b)
/*
* Takes b as input, which should be the information vector
* already multiplied by x^4 (ie. shifted over 4 bits), and
* returns the crc for this input based on the defined generator
* polynomial GENPOLY
*/
{
uint32_t i;
i=1U;
while (b>=16U) { /* >= 2^4, so degree(b) >= degree(genpoly) */
if ((((b >> (20U-i))) & 0x1U) == 1U)
{
b ^= GENPOLY << (16U-i); /* reduce with GENPOLY */
}
LX3301A Rev. 0.1
11
LX3301A Inductive Sensor Interface IC with Embedded MCU
i++;
}
return b;
}
/* Cacluate EEPROM checksum */
sum1=0U;
for(counter=1U; counter<=16U; counter++)
{
if (counter!=3U)
{
sum1+=*EEPROM_address;
}
else
{
sum1+=*EEPROM_address&0x0FFFU;
}
current_address+=4U;
EEPROM_address=current_address;
}
sum2 = makecrc4(((sum1 >> 16)^(sum1&0xFFFFU)) << 4);
FACTORY
This parameter is used to trim the VDD, internal clock frequency and analog front-end amplifier gain. The FACTORY
bits contain factory trimmed information. Recommend not to change. Always read first and preserve these factory
values for future reuse.
Oscillator Trim
The Bit W1[11:7] of the EEPROM is used to set internal clock frequency. This is factory trimmed. Please keep
this value as original value before writing the EEPROM.
VDD Trim
The Bit W1[2:0] of the EEPROM is used to set VDD voltage. This is factory trimmed. Please keep this value as
original value before writing the EEPROM.
Front-End Gain AMPLIFIER
The Bit W1[6:3] of the EEPROM is used to adjust the FRONT-END GAIN AMPLIFIER gain. The bit W1 [6] is
polarity bit, rest three bits(5:3) adjust gains. Default gain [00000b] is 3.125. Each step changes approximately 3%
gain. Smallest number is 1000, largest number is 0111.
TD ,TDHYST and TDPOL
The TD output is enabled using “OUTSEL”. Output polarity of TD is set by “TDPOL”. When TDPOL is set to 1, then
the output pin goes low when the input signal exceeds the 2*TD value, and output pin goes high when the input signal
exceeds the (2*TD-16*TDHYST) value. If TDPOL is set to 0, then the output pin goes high when the input signal
exceeds the 2*TD value and output pin goes low when the input signal lower than the (2*TD-16*TDHYST) value.
TDHYST is used to set the hysteresis value of TD level.
OUTPUT
OUTPUT
TDPOL(W1[12])=0
TDPOL(W1[12])=1
Calculated
Input data
Calculated
Input data
2*TD - 16*TDHYST 2*TD
2*TD -16*TDHYST
2*TD
12
LX3301A Rev. 0.1
Configuration EEPROM
FILTER
This bit selects the digital filter type. If the bit =0, then SINC and if the bit =1 then SINC+FIR.
Filter Bit
Filter Type
SINC
SINC+FIR
0
1
Table 2 - Filter Configuration
REFRESH
This parameter sets the value of the refresh rate of ADC update. If the PWM output is selected the PWM frequency is
always equal to the ADC update rate.
Bit Value
Refresh Rate
2kHz
0
1
2
3
1kHz
500Hz
250Hz
Table 3 - Refresh Bits Configuration
IOSC
These two bits set the Oscillator Tail Current value.
IOSC Bits
Tail Current
Full Range
1/2
Feedback
Enabled
Enabled
Enabled
Enabled
0
1
2
3
1/4
1/8
Table 4 - IOSC Bits Configuration
EELOCK
There are two control signals, one is from the EEWR pin (Active Low – disable to Write EEPROM at EEMODE), and
other is the EELOCK bits on the configuration EEPROM( W14[10]). If the EELOCK bit is set to 1 and EEWR pin is
pulled to low, then EEPROM cannot be written. Default value of W14[10] is 0.
OUTSEL
The OUTSEL bits provide the various output selection option. Table 5 shows the OUTSEL bits versus output option.
Output Configuration
Remarks
Bit 1, Bit 0
AOUT
TD
PWMB(PP)
PWM(PP)
Analog
Bit 3, Bit 2
DOUT
TD
OD_PWMB
OD_PWM
Reserved
00
01
10
11
00
01
10
11
Inverted PWM
PP=Push Pull, OD=Open Drain
Table 5 - OUTSEL Bits Configuration
SCOS
Static Offset Correction of CL1 input channel used in inputs correction calculation.
DCOS
Dynamic Offset Correction of CL1 input channel used in inputs correction calculation.
SSIN
Offset Correction of CL2 input channel used in inputs correction calculation.
DSIN
Dynamic Offset Correction of CL2 input channel used in inputs correction calculation.
GMTCH
Value of the input channel gain mismatch correction gain used in inputs correction calculation.
LX3301A Rev. 0.1
13
LX3301A Inductive Sensor Interface IC with Embedded MCU
OSCOMP
Maximum amplitude of the oscillator swing used in the inputs correction calculation. The maximum value of the
OSCOMP is 255, step 1. Multiplied by 4 to convert as internal OSCOMP data.
ORIGIN
Offset value of the system origin relative to fore-and-after position. This is not a DC output offset adjustment. Verify
LCLMP and HCLMP parameters are not limiting the output range. Multiplied by 2 to convert as internal ORIGIN data.
HCLMP
This parameter is set to high clamp level of output. Output will be clamped at this value if output swing can go above
this level. The HCLMP value used in calculation is 8*value on W11[9:0]. It reduces the maximum output swing.
Maximum level is achieved with HP = 1023.
LCLMP
This parameter sets the low clamp level of output. The output is clamped at this level if output swing can go below this
level. The LCLMP value raises the minimum output value from zero. The LCLMP value used in calculation is 8*value
on W10[9:0]. An output value of “zero” is achieved with LCLMP = 0. LCLMP setting value will overrides the HCLMP
setting if both setting are crossed over.
S0
Slope of first linearization segment.
X1 and Y1
Value of the X and Y coordinates for the first linearization point. Multiplied by 2 to convert as internal data.
X3 and Y3
Value of the X and Y coordinates for the third linearization point. Multiplied by 2 to convert as internal data.
X5 and Y5
Value of the X and Y coordinates for the fifth (and last) linearization point. Multiplied by 2 to convert as internal data.
S5
Slope of the last linearization segment.
Y2
Value of the X2 is calculated by X1, X3 parameters as X2= (X1+X3)/2. Y2 value is the value that can adjust the
coordinates for the second linearization point. Y2 value has polarity and calculated value of second coordinate (y) at
X2 is y= ( Y1+Y3)/2 + Y2. Multiplied by 2 to convert as internal data.
Y4
Value of the X4 is calculated by X3, X5 parameters as X4= (X3+X5)/2. Y4 value is the value that can adjust the
coordinates for the fourth linearization point. Y4 value has polarity and calculated value of fourth coordinate (y) at X4 is
y= ( Y3+Y5)/2 + Y4. Multiplied by 2 to convert as internal data.
CLSEL
CLSEL bit selects CL1 or CL2 inputs as sine or cosine input. When CLSEL set to 1, then CL1 input is selected as sine
value and CL2 input is selected as cosine input. When CLSEL=0, then CL1 input is selected as cosine value and CL2
input is selected as sine value.
14
LX3301A Rev. 0.1
Theory of Operation
Theory of Operation
Oscillator
The on-chip oscillator provides a carrier signal for driving the primary coil of the inductive sensor via pins OSC1
and OSC2. The carrier signal is generated by an internal current source which resonates with the primary inductors
and external capacitors (which forms a tank circuit). The oscillator operates over a frequency range from 1MHz to
5MHz according to the following equation:
ꢁ
ꢀ
ꢆꢇꢇꢇꢇꢈꢉꢊꢋꢊꢇꢄꢇ ꢀ ꢇꢌꢍꢎꢏꢐꢑꢒꢍꢐꢊꢇꢓꢔꢇꢐꢓꢕꢖꢆ ꢅꢇ ꢀ ꢇꢗꢒꢍꢘꢕꢍꢙꢇꢐꢒꢚꢒꢐꢕꢑꢒꢍꢐꢊ
ꢂꢃ ꢄꢅ
√
The value of the inductor L is the most critical element in cross-coupled LC tank oscillator. Because the
inductance is relatively small, the parasitic resistance of L can dominate and impact the ability to maintain oscillation.
As such, the value of inductor L should be as large as possible and with a high Q factor.
In most applications, the inductor L is implemented as traces on a printed circuit board. Depending upon the
processing of the PCB, the height and width of the trace will vary, resulting in a variation of the inductance L and the
parasitic resistance. Because these variations will change from PCB to PCB, it is necessary to calibrate each sensor
PCB independently. Care should be taken to select a PCB source which can achieve manufacturing tolerances
required by a given set of system requirements.
The amplitude of the carrier signal is a function of the primary coil tank circuit configuration and feedback of the
secondary coil signals from the CL1 and CL2 inputs. The shoulder signals of the tank circuit are detected by an
internal circuit. It will distort the sinusoidal waveform if the tank circuit and secondary coil feedback signal is not
within design limits.
In order to detect system faults, the IC monitors the amplitude of the carrier signal on pin OSC1. When the
amplitude is above, or below the specified amplitude (reference electrical spec ‘OSCILLATOR: VOS, Swing Voltage of
OSC1&2’) the AOUT output pin will be forced to 0V. This output level indicates a system fault. When initially
calibrating a sensor, the voltage on OSC1 should be monitored in order to verify that the amplitude is within the
specified range. If the OSC1 voltage is too high, this indicates that the signal levels at CL1 and CL2 may be too low.
If the OSC1 voltage is too low, this indicates that the signal levels at CL1 and CL2 may be too high.
An internal feedback circuit adjusts the current drive of the oscillator in order to maintain the signal relationship
a2 sin2 b2 cos2 k2
; wherein 'k' is the function of the current source amplitude and coefficients 'a' and 'b' are
a2 sin2
b2 cos2
the relative areas of the two secondary coils whose signals are applied to CL1 and CL2. The
and
are obtained by squaring the two input signals CL1 and CL2. In order to reduce the computation complexity, a and b
are typically designed to be matched/equal. When the secondary coils are designed to be equal, the equation
becomes a2 sin2 a2 cos2 a2
. The letter 'a' in the equation is the fixed amplitude of the sensor signals. In
another words, the oscillator circuit adjusts that carrier amplitude such that the input signals into CL1 and CL2 are
maximized. This effectively cancels out non-linearity and variations in the sensor design.
Input Amplifier and Signal Conditioning
Pins CL1 and CL2 are the inputs to two analog signal processing paths. The initial block in each path is a first-
order EMI filter which has a low pass cut-off frequency of 13.5MHz. Following the EMI filter is a demodulator circuit
which removes the carrier such that the relative amplitudes of the CL1 and CL2 signals may be measured. In
addition to demodulation, the circuit includes a phase detector which determines the phase of the input signal relative
to the oscillator signal. This phase detection effectively generates a sign bit which allows for full 360° resolution in
angular measurement applications.
LX3301A Rev. 0.1
15
LX3301A Inductive Sensor Interface IC with Embedded MCU
The output of demodulator is fed to the programmable front-end gain amplifier that can be controlled by “Front-End
Gain AMPLIFIER Gain” in the configuration EEPROM. The amplifier can be programmable with 4 bits, where the
0000b is default gain value that is 3.125. Bit value percentage changes can be done as shown:
Bit
Function
BIT0
BIT1
BIT2
BIT3
Amplification: +3%
Amplification: +6%
Amplification: +12%
Amplification: -24%
The output of the FRONT-END GAIN AMPLIFIER is then passed through an anti-aliasing filter prior to input to the
sigma-delta ADC.
Sigma-Delta ADC with Digital Filters
Each analog path includes a 4th-order 13-bit sigma-delta analog-to-digital converter (ADC) with precision internal
voltage reference which produces true 12-bit measurement results. The sampling frequency for the ADC is derived
from the main clock and selected by “Refresh” in the configuration EEPROM. The sampling clock for the ADC is
derived from the main clock and selected as following table:
Refresh
00
Function
ADC clock=Main clock /8
ADC clock=Main clock /16
ADC clock=Main clock /32
ADC clock=Main clock /64
01
10
11
The ADC decimation filter includes a SINC filter and a half-band FIR filter. The SINC filter provides -40dB of stop-
band attenuation. Because the SINC filter does not provide the same sharp response as a finite/infinite filter
response, a half-band FIR filter is also provided. The drawback of the FIR filter is that it adds delay to the input signal
and this delay depends upon the number of coefficients and the output data rate. The filter can be selected by “Filter”
in the configuration EEPROM.
Embedded MCU
The LX3301 includes an embedded 32-bit microcontroller core which is used to perform filtering and math
functions on the digitized samples from the ADC. The device includes a set of pre-programmed filtering and math
functions which can be selected by setting the appropriate bits in the on-chip configuration EEPROM. Also included
in the on-chip configuration EEPROM are system calibration and linearization coefficient bits.
Configuration EEPROM
The LX3301A includes a user programmable 16 x 16bits EEPROM for storing configuration parameters into non-
volatile memory. The device is placed into EEPROM programming mode (EEMode) by increasing the voltage on the
VIN pin to 13V. Note that a delay of 10ms from power-on must be observed before EEPROM programming mode
can be entered. Data is represented by one of two voltage levels on the VIN pin: a '1' is represented by increasing
the VIN voltage to 16V, while a '0' is represented by decreasing the VIN voltage to 10V. The voltage for a given bit
must be held for a minimum duration of 10µsec and between each bit the voltage must return to 13V for a minimum
of 20µsec (see diagram below):
16
LX3301A Rev. 0.1
Theory of Operation
16V
13V
10V
> 20µsec
1
0
> 20µsec
The first 3bits sent in EEMode are the command followed by the address bit which is corresponds to the logic level
of AOUT. The programming commands are only executed if the address bit and the AOUT logic level match.
For detailed programming, refer to AN-S1410 Application Note for LX3301AQPW EEPROM Programming Guide.
PWM Controller
A 16-bit digital PWM controller is implemented on chip. It can generate a pulse width modulated signal of varying
period and duty cycle. The PWM module has a 2 bit pre-scalar to divide down the MCU clock signal. PWM frequency
is selected by “Refresh” on configuration EEPROM. PWM mode can be set by “OUTSEL”. When the DOUT PWM is
selected, the pull up resistor between DOUT and VIN or VDD is needed, 10kΩ is recommended. PWM frequency is
trimmed at factory.
AOUT
AOUT has three functions that it can be programmed to provide either an analog output (amplified from DAC
output), TD or a PWM output. PWM will be push pull operation. Also it is used as address pin for EEMODE. For
analog output, a 12-bit digital to analog converter is implemented on the chip. The internal DAC supply voltage is
VDD. The AOUT is amplified from DAC output and its supply voltage is from VIN. Therefore, AOUT output range is
limited by the VIN voltage.
Protection
A versatile set of system diagnostic and protection functions are incorporated on the LX3301A to provide reliable
protection of the device and the system. Key fault conditions and outputs status are shown as below table.
Fault condition
Outputs
Status
Remarks
VIN under voltage
Tristate
UVLO
VDD under voltage
Forced low UVLO
VDD unstable or oscillating
CL1,2 disconnected
Forced low VDD noise or improper decoupling
Forced low
CL1,2 signal over voltage
CL1,2 signal too low
Forced low Re-acquire inputs values at next refresh cycle
Forced low Re-acquire inputs values at next refresh cycle
Forced low
OSC1 connection fail
OSC1 over voltage
Forced low
OSC1 under voltage
Forced low
ROM or RAM test failure at startup
EEPROM reading error or RAM writing failure
Periodic ROM checksum failure
Software does not follow intended execution flow
CPU test vector failure
Forced low Restart by µP
Forced low Restart by µP
Forced low Restart by µP
Forced low Restart by µP
Forced low Restart by µP
Reverse Power & GROUND OFF Protection
The LX3301A implements the reverse power protection feature when VIN and GND connections are reversed.
When the power is connection are reversed, then internal circuits are disconnected from the supply and the outputs
are pulled to ground. Also LX3301A implements the ground off protection feature when the ground is disconnected.
LX3301A Rev. 0.1
17
LX3301A Inductive Sensor Interface IC with Embedded MCU
High Voltage LDO
A high voltage, low temperature drift, low-dropout, precision voltage regulator is implemented on chip. The
regulator provides the internal power to the chip and also provides power for external components such as pull-up
resistors. Decoupling caps is required to ensure high performance analog measurements; recommended value is
1µF. VDD is pre-trimmed at factory.
18
LX3301A Rev. 0.1
Reference Schematics
Reference Schematics
VIN
PCB inductor(coils)
coupled OSC &
Sensor
Coupler Board
(Movable) Air coupled to
Sensor Board
VIN
VIN
Cc
U1
LX3301AQPW
2.2nF *2
R4
10K
R1
10K
25V
1
2
3
4
5
6
7
14
13
12
11
10
9
GND
DOUT
AOUT
VIN
SUB
C1
C2
680pF *1
OSC1
OSC2
EEWR
CL2
DOUT
AOUT
680pF *1
R2
VDD
VIN
NU
VDD
R3
VDD
NC
C3
C6
C4
10K
GNDCL
CL1
1nF 100nF 1uF
25V
50V
50V
8
NC
Note *1: Cap value is reference only. Need to select it to set desired
oscillation frequency.
*2: Cap value is reference only. Need to select it to resonate at
oscillation frequency of sensor board.
Figure 4 · LX3301A 14-Pin Reference Schematic
LX3301A Rev. 0.1
19
LX3301A Inductive Sensor Interface IC with Embedded MCU
Package Outline Dimensions
Controlling dimensions are in millimeters, inches equivalents are shown for general information.
MILLIMETERS
Dim
INCHES
MIN
MIN
–
MAX
1.10
0.15
0.95
0.30
0.20
5.10
MAX
0.043
0.006
0.037
0.012
0.008
0.201
A
A1
A2
b
–
0.05
0.85
0.19
0.09
4.90
0.002
0.033
0.007
0.004
0.193
E
E1
1 2 3
e
c
D
D
E
6.4 BSC
0.252
E1
e
4.30
4.50
0.169
0.177
A2
A
0.65 BSC
0.026 BSC
SEATING PLANE
L
b
c
L
0.45
0°
0.75
8°
0.017
0°
0.030
8°
A1
θ
Θ
*Lead Coplanarity
Note:
1.Dimensions do not include mold flash or protrusions;
these shall not exceed 0.155mm (.006”) on any side.
Lead dimension shall not include solder coverage
Figure 6 · PW 14-Pin TSSOP Package Dimensions
PRELIMINARY DATA – Information contained in this document is pre-production
data and is proprietary to Microsemi. It may not be modified in any way without the
express written consent of Microsemi. Product referred to herein is offered in pre-
production form only and may not have completed Microsemi’s Quality Assurance
process for Release to Production. Microsemi reserves the right to change or
discontinue this proposed product at any time.
20
LX3301A Rev. 0.1
Preliminary Datasheet
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markets. Products include high-performance and radiation-hardened analog mixed-signal
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LX3301A 0.1/07.15
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