OP77

Rev. E | Page 12 of 16

PRECISION CURRENT SINKS

V+

200

Ω

R1

1

Ω

1W

IRF520

OP77

FULL SCALE OF 1V.

R1

Figure 31. Positive Current Sink

200

Ω

R1

IRF520

V–

OP77

R1

Figure 32. Positive Current Source

The simple high-current sinks, shown Figure 31 and Figure 32,

require the load to float between the power supply and the sink.

the OP77 ensure high accuracy.

inputs from microvolts to volts. In Figure 33, the signal always

appears as a common-mode signal to the op amps. The

OP77EZ CMRR of 1 μV/V ensures errors of less than 2 ppm.

+15V

–15V

1k

Ω

1k

Ω

R3

2k

Ω

C1

30pF

D1

1N4148

7

6

4

2

3

0.1µF

0.1µF

2N4393

+15V

D2

–15V

7

6

4

2

3

0.1µF

0.1µF

OP77E

OP77E

Figure 33. Precision Absolute Value Amplifier

100

Ω

15V

0.1µF

OP77

100

Ω

100

Ω

10µF

6

4

REF-01

2

6

4

REF-01

2

6

4

REF-01

2

+

Figure 34. Low Noise Precision Reference