Low-Cost Precision Sensor

Signal Conditioner

______________________________________________________________________________________

23

∑

∑

∑

∆

EEPROM

(LOOKUP PLUS CONFIGURATION DATA)

FSO

DAC

UNLOCK

16-BIT

16-BIT

8-BIT

LOOKUP

ADDRESS

BANDGAP

TEMP

SENSOR

PGA

MUX

MUX

FSOTC REGISTER

ISRC

75k

Ω

75k

Ω

BDR

FSOTC

INP

INM

FSOTC

DAC

EEPROM ADDRESS

15EH + 15FH

000H + 001H

:

OFFSET DAC LOOKUP TABLE

CONFIGURATION REGISTER SHADOW

USAGE

19EH + 19FH

16CH + 16DH

:

USER STORAGE (52 BYTES)

2FEH + 2FFH

1A0H + 1A1H

:

FSO DAC LOOKUP TABLE

160H + 161H

RESERVED

162H + 163H

OFFSET TC REGISTER SHADOW

164H + 165H

RESERVED

166H + 167H

FSOTC REGISTER SHADOW

168H + 169H

CONTROL LOCATION REGISTER

16AH + 16BH

OFFSET

DAC

±1

±1

✕

26

PHASE

REVERSAL

MUX

OUT

AMP-

AMPOUT

AMP+

PGA GAIN

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

7.0

7.5

8.0

9.0

8.5

PGA (3:0)

0000

0001

0010

0011

0100

0101

0110

0111

1000

1001

1010

1011

1100

1101

1111

1110

TOTAL GAIN

39

52

65

78

91

104

117

130

143

156

169

182

195

208

234

221

IRO (3, 2:0)

OFFSET mV

63

54

45

36

27

18

9

0

0

-9

-18

-27

-36

-45

-63

-54

1,111

1,110

1,101

1,100

1,011

1,010

1,001

1,000

0,000

0,001

0,010

0,011

0,100

0,101

0,111

0,110

16-BIT

OFFSET

TC DAC

OTC REGISTER

INPUT REFERRED OFFSET

(COARSE OFFSET)

PROGRAMMABLE GAIN STAGE

UNCOMMITTED OP AMP

VALUE

±20mV

±0.01V

±0.25V

10MHz TYPICAL

PARAMETER

I/P RANGE

I/P OFFSET

O/P RANGE

NO LOAD

1mA LOAD

UNITY GBW

PGA BANDWIDTH

≈ 3kHz ± 10%

16-BIT

*INPUT REFERRED

OFFSET VALUE IS

VALUES GIVEN ARE FOR

PGA BANDWIDTH

≈

3kHz

± 10%

TEST

CLK1M

DIO

DIGITAL

INTERFACE

Detailed Block Diagram