AN7220 Radio Chip & Circuit

The AN7220 is a single chip radio solution, which provides AM and FM radio bands. The radio chip requires a few external components, however as you can see, in today's terms this can amount to many components.

AN7220 Pinout

This IC has a built-in IF amplifier, and therefore the circuit operation and sensitivity are excellent, however this chip requires 6.6 V at 10 mA to operate, hence the need for four AA size dry cells. The power consumption is 66 mW, which made this unit expensive to run in the 80s. However, on the positive side, the radio sensitivity is excellent, and with modern rechargeable Ni-MH batteries, cost is not an issue.

Circuit Diagram

Interesting to note that pin 6 and pin 7 are for the IF-bypass. Pin 14 drives an LED for the tuning indicator, and pin 9 connects to the FM detector coil. Pin 1 is for the AM RF-input. When I was younger I could have hours of fun modifying the circuit to increase the frequency range. This is quite a simple circuit for radio electronics enthusiasts who like building vintage radios.

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