tda1521q NXP Semiconductors, tda1521q Datasheet - Page 8

• Manufacturer Part Number: tda1521q
• Description: 2 X 12 W Hi-fi Audio Power Amplifier
• Manufacturer: NXP Semiconductors

Philips Semiconductors
Product specification
TDA1521
2 x 12 W hi-fi audio power amplifier
TDA1521Q
APPLICATION INFORMATION
Input mute circuit
The input mute circuit operates only during switching on and off of the supply voltage. The circuit compares the 1/2 supply
voltage (at pin 3) with an internally fixed reference voltage (V
), derived directly from the supply voltage. When the
ref
voltage at pin 3 is lower than V
the non-inverting inputs (pins 1 and 9) are disconnected from the amplifier. The voltage
ref
at pin 3 is determined by an internal voltage divider and the external 100 F capacitor.
During switching on, a time delay is created between the reference voltage and the voltage at pin 3, during which the
input terminal is disconnected, (as illustrated in Fig.3).
Fig.3 Input mute circuit; time delay.
July 1994
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