Chopper-Stabilized Op Amps

10

______________________________________________________________________________________

-INPUT

+INPUT

V-

EXT/CLK IN

INT/EXT

INT/

CLK OUT

V+

OUTPUT

CLAMP

0.069"

(1.75mm)

0.090"

(2.29mm)

ICL7660

45

3

8

6

2

10

µF

10

µF

1M

+15V

+7.5V

0V

Chip Topography

Figure 8. Splitting +15V with an ICL7660, 95% Efficiency

(Same for -15V)

ICL7650

OUTPUT

INPUT

C

R

C

CLAMP

0.1

µF 0.1µF

R3

R2

R1

NOTE: R1 || R2 INDICATES THE

PARALLEL COMBINATION OF

R1 || R2.

R3 + (R1 || R2) > 100k

Ω

FOR FULL CLAMP EFFECT

ICL7650

IN

+

-

CLAMP

0.1

µF

-7.5V

-15V

10k

10k

+15V

+7.5V

0.1

µF

741

OUT

Figure 6. Noninverting Amplifier with Optional Clamp

Figure 7. Using an Industry-Standard 741 to Boost Output

Drive Capability