TA8122AF Radio Chip

The Sony WM-BF22 has a radio tuner, which uses the 24-pin TA8122AF integrated circuit (IC) manufactured by the Toshiba Corporation. This was a widely used IC for portable radio applications due to its extremely low power consumption and external component count. It has an operating voltage range of 1.8 V to 7.0 V.

Circuit Diagram

This is a single chip radio circuit for the TA8122AF. As you can see, very few external components are required in this design. This IC has a built-in AM/FM IF blocks, and FM stereo detection circuitry. In addition, the AM detector coil, and IF coupling capacitors are not required thus further simplifying the circuit. For adopting the ceramic discriminator and ceramic resonator, it is not necessary to adjust the FM quad detector circuit and FM VCO circuit. This IC also provides S curve characteristics of FM detection output, which is remarkable for a Walkman radio.

Ferrite Rod

This is the ferrite rod and coil, which is part of the AM antenna circuit connecting to pin 24 on the chip as shown in the circuit above.

Tuning Capacitor

This neat little tuning capacitor is multi-ganged, which is necessary when tuning for AM and FM reception. I love those neat looking little tuning coil cans. This is an inspiring neat build, and many radio engineers and students find great insight from it.

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