1

CA3280, CA3280A

Dual, 9MHz, Operational

Transconductance Amplifier (OTA)

The CA3280 and CA3280A types consist of two variable

operational amplifiers that are designed to substantially reduce

the initial input offset voltage and the offset voltage variation

with respect to changes in programming current. This design

results in reduced “AGC thump,” an objectionable characteristic

of many AGC systems. Interdigitation, or crosscoupling, of

critical portions of the circuit reduces the amplifier dependence

upon thermal and processing variables.

The CA3280 has all the generic characteristics of an

operational voltage amplifier except that the forward transfer

characteristics is best described by transconductance rather

than voltage gain, and the output is current, not voltage. The

magnitude of the output current is equal to the product of

transconductance and the input voltage. This type of

operational transconductance amplifier was first introduced in

1969, and it has since gained wide acceptance as a gateable,

gain controlled building block for instrumentation and audio

applications, such as linearization of transducer outputs,

standardization of widely changing signals for data processing,

multiplexing, instrumentation amplifiers operating from the

nanopower range to high current and high speed comparators.

For additional application information on this device and on

OTAs in general, please refer to Application Notes: AN6818,

AN6668, and AN6077.

Pinout

CA3280

(PDIP, CERDIP)

TOP VIEW

Features

• Low Initial Input Offset Voltage: 500

µV (Max) (CA3280A)

for All Types

• Low Offset Voltage Drift: 5

• Excellent Matching of the Two Amplifiers for All

Characteristics

• Internal Current-Driven Linearizing Diodes Reduce the

External Input Current to an Offset Component

• Flexible Supply Voltage Range. . . . . . . . . . .

±2V to ±15V

Applications

• Voltage Controlled Amplifiers

• Voltage Controlled Oscillators

• Multipliers

• Demodulators

• Sample and Hold

• Instrumentation Amplifiers

• Function Generators

• Triangle Wave-to-Sine Wave Converters

• Comparators

• Audio Preamplifier

14

15

16

9

13

12

11

10

1

2

3

4

5

7

6

8

EMITTER, A1

V-

NC

EMITTER, A2

+IN, A1

V+, A1

OUT, A1

OUT, A2

V+, A2

-IN, A2

+IN, A2

-IN, A1

-

+

A1

-

+

A2

Ordering Information

PART NUMBER

TEMP.

PACKAGE

PKG.

NO.

CA3280AE

-55 to 125

16 Ld PDIP

E16.3

CA3280E

0 to 70

16 Ld PDIP

E16.3

CA3280AF3

-55 to 125

16 Ld CERDIP

F16.3

Data Sheet

September 1998

File Number

1174.4

CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.

1-888-INTERSIL or 321-724-7143