Philips TDA8560Q Datasheet page 5

Philips Semiconductors
2 40 W/2 stereo BTL car radio
power amplifier with diagnostic facility
S -
HORT CIRCUIT PROTECTION
When a short-circuit occurs at one or more outputs to
ground or to the supply voltage, the output stages are
switched off until the short-circuit is removed and the
device is switched on again, with a delay of approximately
20 ms, after removal of the short-circuit. During this
short-circuit condition, pin 12 is continuously low.
When a short-circuit across the load of one or both
channels occurs the output stages are switched off during
approximately 20 ms. After that time it is checked during
approximately 50 s to see whether the short-circuit is still
present. Due to this duty cycle of 50 s/20 ms the average
current consumption during this short-circuit condition is
very low (approximately 40 mA).
current
handbook, full pagewidth
in
output
stage
V 12
V P
1996 Jan 08
short-circuit over the load
50 s
Fig.4 Short-circuit waveform.
During this short-circuit condition, pin 12 is low for 20 ms
and high for 50 s (see Fig.4).
The power dissipation in any short-circuit condition is
very low.
T
EMPERATURE DETECTION
When the virtual junction temperature T
pin 12 will become continuously low.
O
PEN COLLECTOR OUTPUT
Pin 12 is an open collector output, which allows pin 12 of
more devices being tied together.
20 ms
5
Product specification
TDA8560Q
reaches 150 C,
vj
MGA722
t
t