Philips Semiconductors
Product specification
2 x 22 W BTL stereo car radio power
amplifier with speaker protection
TDA1557Q
PINNING
FUNCTIONAL DESCRIPTION
The TDA1557Q contains two identical amplifiers with
differential input stages, and can be used for bridge
applications. The gain of each amplifier is fixed at 46 dB.
Special features of this device are:
SYMBOL
PIN
DESCRIPTION
INP1
1
2
input 1
GND1
VP1
ground (signal)
supply voltage 1
output 1A
3
a. mute/stand-by switch
low stand-by current
OUT1A
GND
4
5
power ground 1
output 1B
low mute/stand-by switching current (low cost supply
switch)
OUT1B
OUT2A
GND
6
7
output 2A
mute facility
8
power ground 2
output 2B
b. loudspeaker protection
OUT2B
VP2
9
when a short circuit to ground is made, which forces a
DC voltage of ≥ 1 V across the loudspeaker, a built-in
protection circuit becomes active and limits the DC
voltage across the loudspeaker to ≤ 1 V
10
11
12
13
supply voltage 2
mute/stand-by switch
input reference voltage
input 2
M/SS
Vref
INP2
c. the harmonic distortion at low frequencies can be
decreased by connecting two diodes to ground at pin 12.
handbook, halfpage
INP1
1
2
GND1
V
3
P1
OUT1A
GND
4
5
OUT1B
OUT2A
GND
6
7
TDA1557Q
8
OUT2B
9
V
10
P2
M / SS 11
V
12
ref
INP2 13
MCD322 - 1
Fig.2 Pin configuration.
May 1992
4
NXP [ NXP ]
