Datasheet Intersil CA3280

DATASHEET
CA3280, CA3280A FN1174
Rev 6.00
May 2002 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, …