July 1994
4
Philips Semiconductors
Product specification
2 x 6 W hi-fi audio power amplifier
TDA1521A
PINNING
FUNCTIONAL DESCRIPTION
This hi-fi stereo power amplifier is designed for mains fed applications. The circuit is designed for both symmetrical and
asymmetrical power supply systems. An output power of 2
×
6 watts (THD = 0,5%) can be delivered into an 8
Ω
load with
a symmetrical power supply of
±
12 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 device is a mute circuit which suppresses unwanted input signals during switching on and off.
Referring to Fig.12, the 100
µ
F 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 circuits activate at 150
°
C allowing safe operation to
a maximum junction temperature of 150
°
C without added distortion.
RATINGS
Limiting values in accordance with the Absolute Maximum System (IEC 134)
Note
1. For asymmetrical power supplies (at short circuiting of the load) the maximum supply voltage is limited to V
P
= 28 V.
1
−
INV1
non-inverting input 1
5
−
V
P
negative supply (symmetrical)
2
INV1
inverting input 1
ground (asymmetrical)
3
GND
ground (symmetrical)
6
OUT2
output 2
1
⁄
2
V
P
(asymmetrical)
7
+ V
P
positive supply
4
OUT1
output 1
8
INV2
inverting input 2
9
−
INV2
non-inverting input 2
PARAMETER
CONDITIONS
SYMBOL
MIN.
MAX.
UNIT
Supply voltage
pin 7
V
P
= V
7-3
−
+21
V
pin 5
−
V
P
= V
5-3
−
−
21
V
Non-repetitive peak
output current
pins 4 and 6
I
OSM
−
4
A
Total power dissipation
see Fig.2
P
tot
Storage temperature range
T
stg
−
55
+ 150
°
C
Junction temperature
T
j
−
150
°
C
Short-circuit time:
see note 1
outputs short-circuited
to ground
symmetrical
(full signal drive)
power supply
t
sc
−
1
hour
asymmetrical
power supply
t
sc
−
1
hour
