DATASHEET CA3280, CA3280A FN1174 Dual, 9MHz, Operational Transconductance Amplifier (OTA) Rev 6.00 May 2002 The CA3280 and CA3280A types consist of two variable Features operational amplifiers that are designed to substantially reduce the initial input offset voltage and the offset voltage variation • Low Initial Input Offset Voltage: 500V (Max) (CA3280A) with respect to changes in programming current. This design • Low Offset Voltage Change vs IABC: <500V (Typ) results in reduced “AGC thump,” an objectionable characteristic for All Types of many AGC systems. Interdigitation, or crosscoupling, of • Low Offset Voltage Drift: 5V/oC (Max) (CA3280A) critical portions of the circuit reduces the amplifier dependence upon thermal and processing variables. • Excellent Matching of the Two Amplifiers for All Characteristics The CA3280 has all the generic characteristics of an operational voltage amplifier except that the forward transfer • Internal Current-Driven Linearizing Diodes Reduce the characteristics is best described by transconductance rather External Input Current to an Offset Component than voltage gain, and the output is current, not voltage. The • Flexible Supply Voltage Range . 2V to 15V magnitude of the output current is equal to the product of transconductance and the input voltage. This type of Applications operational transconductance amplifier was first introduced in 1969, and it has since gained wide acceptance as a gateable, • Voltage Controlled Amplifiers gain controlled building block for instrumentation and audio • Voltage Controlled Oscillators applications, such as linearization of transducer outputs, standardization of widely changing signals for data processing, • Multipliers multiplexing, instrumentation amplifiers operating from the • Demodulators nanopower range to high current and high speed comparators. • Sample and Hold For additional application information on this device and on OTAs in general, please refer to Application Notes: AN6818, • Instrumentation Amplifiers AN6668, and AN6077. • Function Generators Pinout • Triangle Wave-to-Sine Wave Converters • Comparators CA3280 (PDIP) TOP VIEW • Audio Preamplifier I1A116D, A1+IN, A1+Functional DiagramEMITTER, A1 2-15 -IN, A1I314ABC, A1V+, A1V- 413 OUT, A1141/2 CA3280NC 512 OUT, A211I611ABC, A2V+, A2EMITTER, A2 7A210 -IN, A2-I8+9D, A2+IN, A2- 15107 2+Ordering Information161392K2K12TEMP.PKG.18PART NUMBERRANGE (oC)PACKAGENO.4 CA3280AE -55 to 125 16 Ld PDIP E16.3 36 CA3280E 0 to 70 16 Ld PDIP E16.3 FN1174 Rev 6.00 Page 1 of 10 May 2002