July 1994 4
Philips Semiconductors Product specification
2 x 22 W stereo BTL differential amplifier
with speaker protection and dynamic TDA1556Q
PINNING
SYMBOL PIN DESCRIPTION
IN1A 1 input signal 1A
IN1B 2 input signal 1B
n.c. 3 not connected
DDD 4 dynamic distortion detector
Vp1 5 positive supply voltage 1
OUT1A 6 output signal 1A
GND1 7 power ground 1
OUT1B 8 output signal 1B
n.c. 9 not connected
OUT2A 10 output signal 2A
GND2 11 power ground 2
OUT2B 12 output signal 2B
VP2 13 positive supply voltage 2
M/SB 14 mute/stand-by switch
LSP 15 loudspeaker protection
IN2A 16 input signal 2B
IN2B 17 input signal 2A
Fig.2 Pin configuration.
handbook, halfpage
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
IN 1A
IN 1B
n.c.
DDD
OUT 1A
GND 1
OUT 1B
n.c.
GND 2
OUT 2B
M/SB
LSP
IN 2A
IN 2B
MLA381 - 1
TDA1556Q
OUT 2A
VP2
VP1
THERMAL RESISTANCE
SYMBOL PARAMETER THERMAL
RESISTANCE
Rth j-a from junction to ambient
in free air 40 K/W
Rth j-c from junction to case
(see Figs 3 and 4) 1.5 K/W
Fig.3 Thermal resistance.
handbook, halfpage
2.8 
K/W
0.1 
K/W
2.8 
K/W
virtual 
junction
output 1 output 2
case
MLA382