Philips Semiconductors
Product specification
2 × 25 W BTL stereo car radio power amplifier
with differential inputs and diagnostic outputs
TDA8566Q
PINNING
SYMBOL
PIN
DESCRIPTION
handbook, halfpage
IN1+
1
2
3
4
5
6
7
channel 1 input positive
channel 1 input negative
small signal ground
1
2
3
4
5
6
7
8
9
IN1+
IN1−
IN1−
SGND
CLIP
SGND
CLIP
clip-detection
VP1
supply voltage 1
V
P1
OUT1+
PGND1
channel 1 speaker output positive
OUT1+
PGND1
OUT1−
n.c.
channel 1 negative power supply
(ground)
OUT1−
n.c.
8
9
channel 1 speaker output negative
not connected
TDA8566Q
OUT2+
PGND2
10
11
channel 2 speaker output positive
OUT2+ 10
channel 2 negative power supply
(ground)
PGND2 11
OUT2−
VP2
12
13
14
channel 2 speaker output negative
supply voltage 2
12
13
OUT2−
V
P2
MODE
mode select switch
(stand-by/mute/operating)
MODE 14
15
16
DIAG
DIAG
15
short-circuit and temperature
pre-warning diagnostic
IN2+
IN2+
16
17
channel 2 input positive
channel 2 input negative
IN2− 17
IN2−
MGD101
Fig.2 Pin configuration.
Since this pin has a very low input current (< 40 µA), a low
cost supply switch can be applied. To avoid switch-on
plops, it is advisable to keep the amplifier in the mute mode
for a period of ≥150 ms (charging the input capacitors at
pins 1, 2, 16 and 17). This can be realized by
microcontroller control or by an external timing circuit
(see Fig.7).
FUNCTIONAL DESCRIPTION
The TDA8566Q contains two identical amplifiers and can
be used for BTL applications. The gain of each amplifier is
fixed at 26 dB. Special features of this device are:
1. Mode select switch
2. Clip detection
3. Short-circuit diagnostic
4. Temperature pre-warning
5. Open-collector outputs
6. Differential inputs.
Clip detection (pin 4)
When clipping occurs at one or more output stages, the
dynamic distortion detector becomes active and pin 4
goes low. This information can be used to drive a sound
processor or DC volume control to attenuate the input
signal and so limit the level of distortion. The output level
of pin 4 is independent of the number of channels that are
being clipped. The clip detection circuit is disabled in a
short-circuit condition, so if a fault condition occurs at the
outputs, pin 4 will remain at a high level. The clip detection
waveforms are illustrated in Fig.3.
Mode select switch (pin 14)
• Standby: low supply current (< 100 µA)
• Mute: input signal suppressed
• Operating: normal on condition.
1998 Sep 23
4
NXP [ NXP ]
