®

REF200

10

FIGURE 12. Precision Triangle Waveform Generator.

FIGURE 11. RTD Excitation With Three Wire Lead Resistance Compensation.

1N4148

1N4148

1N4148

1N4148

Bidirectional

Current Source

1/2

REF200

OPA602

R

C

Triangle Output

Square Output

2Vp-p

2Vp-p

10k

Ω

Frequency = 1/4RC (Hz)

Frequency = 25/C (Hz)

(C is in µF and R = 10k

Ω)

7

V

= Gain • 200µA •

∆ RTD

OUT

AB

O

C

I

–V

S

+V

S

RTD

Cable Shield

200µA

Reference

Current

200µA

Compensation

Current

REF200

1

R

OFFSET

INA110

Instrumentation Amplifier

23

4

86

5