TC911A/TC911B

DS21481C-page 2

© 2005 Microchip Technology Inc.

General Description

The TC911 CMOS auto-zeroed operational amplifier is

the first complete monolithic chopper stabilized ampli-

fier. Chopper operational amplifiers like the ICL7650/

7652 and LTC1052 require user supplied, external off-

set compensation storage capacitors. External capac-

itors are not required with the TC911. Just as easy

to use as the conventional OP07 type amplifier, the

TC911 significantly reduces offset voltage errors.

Pinout matches the OP07/741/7650 8-pin mini-DIP

configuration.

Several system benefits arise by eliminating the exter-

nal chopper capacitors: lower system parts count,

reduced assembly time and cost, greater system reli-

ability, reduced PC board layout effort and greater

board area utilization. Space savings can be significant

in multiple amplifier designs.

Electrical specifications include 15

μV maximum offset

voltage and 0.15

μV/°C maximum offset voltage tem-

perature co-efficient. Offset voltage error is five times

lower than the premium OP07E bipolar device. The

TC911 improves offset drift performance by eight

times.

The TC911 operates from dual or single power sup-

plies. Supply current is typically 350

μA. Single 4.5V to

16V supply operation is possible, making single 9V bat-

tery operation possible. The TC911 is available in 2

package types: 8-pin plastic DIP and SOIC.

Functional Block Diagram

+

–

+

–

V

SS

TC911A

TC911B

-Input

+Input

A

2

3

47

B

*

*

A

B

6

Main Amplifier

Low Impedance

Output Buffer

Internal Oscillator

200HZ)

Correction Amplifier

+

–

Output

Note: Internal capacitors. No external capacitors required.