TDA1521 two-channel power amplifier OTL connection and OCL connection

Philips' TDA1521 two-channel audio power amplifier integrated circuit has a good reputation among audiophiles due to its good sound quality and easy production. TDA1521 adopts a nine-pin single-in-line plastic package, with high output power, small gain difference between the two channels, and overheating, overload and short circuit protection.

In actual circuit applications, the internal resistance of the power supply powering TDA1521 should be less than 4 ohms to ensure that its load short-circuit protection circuit can operate reliably. TDA1521 must be equipped with a heat sink plate not less than 200mm×100mm×2mm. During the debugging process, do not try to connect the output terminal of the TDA1521 to the input terminal, otherwise the integrated block will burn out quickly.

TDA1521 characteristic parameters: (Vcc=±16V RL=8Ω f=1KHz Ta=25℃)

In high-fidelity audio, TDA1521 is connected to a dual power supply circuit to work. The purpose is to remove the coupling capacitor of the power output and directly connect it to the speaker to improve the sound quality of the playback.