ALFA RPAR AS3340 / AS3340A VCO IC - CEM3340 Replacement

The AS3340 is Alfa’s fantastic clone of the famous CEM3340 voltage-controlled oscillator.

Just like the beloved CEM3340, the AS3340 and AS3345 are completely self contained, precision voltage controlled oscillators, featuring both exponential and linear control scales and up to four buffered output waveforms: triangle, sawtooth, square, and pulse with voltage controllable pulse width. Full temperature compensation makes these VCOs extremely stable, and eliminates the need for a temperature compensation resistor. The highly accurate exponential and linear control inputs are virtual ground summing nodes, allowing multiple control voltages to be mixed within the device itself. Also included is provision for hard and soft synchronization of the frequency, and an output for easy adjustment of high frequency tracking. Special care in the design ensures oscillation start-up under any power-on sequence and supply conditions. An on-chip 7.4 volt Zener diode allows the device to operate off ±15 volt supplies, as well as +12, -5 volt supplies. For voltages greater than -7.5 volts, a series current limiting resistor REE must be added between pin 3 and the negative supply. 

The AS3340 /AS3340A is available in DIP16 thru-hole and SOIC16 SMT configurations. Also available is the AS3340HYB, a DIP16 compatible adapter PCB with the QFN24 SMT IC already soldered in place. 

AS3340 Datasheet

A great article with tons of useful information, beyond the datasheet: AS3340 Article

Here is a wonderful Wikipedia page that lists original CEM and SSM chips in synthesizers to help with replacment decisions: CEM/SSM Wiki