LTC1043

14

1043fa

Frequency-Controlled Gain Amplifier

LTC1043 • A21

5V

–5V

–5V

2

3

4

6

7

–

+

LT1056

3

10k

33k

22M

SENSOR

* = 1% FILM RESISTOR

LT1004

1.2V

500

90%

RH TRIM

10k

5% RH TRIM

2

1

100pF

9k*

1k*

SENSOR = PANAMETRICS # RHS

≈ 500pF AT RH = 76%

1.7 pF/%RH

6

8

–

+

LM301A

OUTPUT

0V TO 1V = 0% TO 100%

1µF

100pF

0.01µF

1µF

1/4 LTC1043

12

1/4 LTC1043

11

8

7

16

17

14

13

1k*

470k

Relative Humidity Sensor Signal Conditioner

GAIN CONTROL

0kHz TO 10kHz = GAIN 0 TO 1000

0.01µF

1/2 LTC1043A

FOR DIFFERENTIAL INPUT, GROUND PIN 8A AND USE PINS 13A AND 7A FOR INPUTS

FOR SINGLE-ENDED INPUT AND POSITIVE GAIN, GROUND PIN 8A AND USE PIN 7A FOR INPUT

USE ± 5V SUPPLIES FOR LTC1043

5V

2

7

6

4

3

–5V

LTC1043 • A20

100pF

1/2 LTC1043B

1kHz • 100pF

–

+

LT1056

11A

11B

12B

12A

0.01µF

13A

14A

8A

7A

16A

13B

8B

7B

16B

14B

GAIN =

; GAIN IS NEGATIVE AS SHOWN

TYPICAL APPLICATIO S