Voltage Synthesized Electronic Tuning System LSI for AM/FM Radio

The AM/FM radio adopting electronic tuning systems are increasing in number spreading from car radios to home stereos. The electronic tuning system electronically controls the DC tuning-voltage to the varactor diodes in the receiver circuits, instead of mechanically controlling the variable capacitor or a variable inductance coil, tuning the receiver to the desired channel. The electronic control system fits the demand toward smaller size and increasing functions of a radio, also cost reduction by LSI prompts the tendency to use the electronic tuning system in radios.