The AS3280 is Alfa’s version of the CA3280 IC. The AS3280 consists 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. Careful design of critical places of the circuit reduces the amplifier dependence upon thermal and processing variables.

The AS3280 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 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.

The AS3280 is available in a 16-pin DIP package.

Features

• Low Initial Input Offset Voltage: 1.8mV (Max)
• Low Offset Voltage Change vs IABC: <500 µV (Typ)
• Low Offset Voltage Drift: 5µV/°C
• 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
• Oscillators
• Multipliers
• Demodulators
• Sample and Hold
• Instrumentation Amplifiers
• Function Generators
• Triangle Wave-to-Sine Wave Converters
• Comparators
• Audio Preamplifier