TDA1521Q

These products are not designed for use in life support appliances, devices, or systems where malfunction of these products can reasonably be expected to result in personal injury. Philips customers using or selling these products for use in such applications do so at their own risk and agree to fully indemnify Philips for any damages resulting from such improper use or sale.

This hi-fi stereo power amplifier is designed for mains fed applications. The TDA1521Q is designed for both symmetrical and asymmetrical power supply systems. An output power of 2  ×´ 12 watts (THD = 0,5%) can be delivered into an 8 W load with a symmetrical power supply of ± 16 V.

The gain is fixed internally at 30 dB. Internal gain fixing gives low gain spread and very good balance between the
amplifiers (0,2 dB).
A special feature of this TDA1521Q is a mute circuit which suppresses unwanted input signals during switching on and off. Referring to Fig.13, the 100 mF capacitor creates a time delay when the voltage at pin 3 is lower than an internally fixed reference voltage. During the delay the amplifiers remain in their DC operating mode but are isolated from the non-inverting inputs on pins 1 and 9.
Two thermal protection circuits are provided, one monitors the average junction temperature and the other the
instantaneous temperature of the power transistors. Both protection TDA1521Q circuits activate at 150 °C allowing safe operation to a maximum junction temperature of 150°C without added distortion.