CA3280 Transconductance Amplifier

Contents hide

1 Operational Transconductance Amplifier (OTA)

The CA3280 IC consists of two op-amps, configured to substantially reduce the initial offset voltage variation while keeping in check the offset voltage variation with respect to the changes in coded current. The IC has offers a wide variety of features such as high noise immunity and ESD protection, etc. CA3280 is widely accepted as the base standard for instrumentation and audio applications, such as linearization of transducer outputs.

Operational Transconductance Amplifier (OTA)

Operational transconductance amplifier is basically an amplifier, that produces an output current, when a differential input voltage is applied. It is also known as a voltage to current converter. OTA amplifiers are similar to general amplifier, with the only difference being that an OTA has a high impedance differential input stage, that may be used with negative feedback.

CA3280 Pinout

CA3280 Pin Configuration

Pin No	Pin Name	Description
1	ID, A1	Input Current A1
2	EMITTER, A1	Emitter Current A1
3	IABC, A1	Amplifier Bias Current A1
4	V-	Negative Power Supply
5	NC	No Connection
6	IABC, A2	Amplifier Bias Current A2
7	EMITTER, A2	Emitter Current A2
8	ID, A2	Input Current A2
9	+IN, A2	Non Inverting Amplifier A2
10	-IN, A2	Inverting Amplifier A2
11	V+, A2	Positive Power Supply A2
12	OUT, A2	Output Pin A2
13	OUT, A1	Output Pin A1
14	V+, A1	Positive Power Supply A1
15	-IN, A1	Inverting Amplifier A1
16	+IN, A1	Non Inverting Amplifier A1

How To Use CA3280

The above circuit represents the function of the CA3280 in a channel separation test. For this, provide a non – inverting input (op-amp 1) on pin 16 of the IC, while keeping the inverting input at GND. Provide an appropriate Vcc and Vss on pins 14 and 4 of the IC. The amplifier output of the circuit can be taken to an oscilloscope through pin 13 of the IC.

CA3280 Features and Specifications

Low Initial Input Offset Voltage: 500µV (Max) (CA3280A)
Low Offset Voltage Change vs IABC: <500µV (Typ) for All Types
Low Offset Voltage Drift: 5µV/oC (Max) (CA3280A)
Excellent Matching of the Two Amplifiers for All Characteristics
Internal Current-Driven Linearizing Diodes Reduce the External Input Current to an Offset Component