1996 Jan 08 11
Philips Semiconductors Product specification
2 × 40 W/2 Ω stereo BTL car radio
power amplifier with diagnostic facility TDA8560Q
Fig.7 Mode select switch circuitry.
handbook, halfpage
100 kΩ
MGA708
47 µF
10 kΩ10 kΩ
mode
select
switch
VP
Diagnostic output
Special care must be taken in the printed-circuit board
layout to separate pin 12 from pin1 and pin 13, to
minimize the crosstalk between the diagnostic output and
the inputs.
Mode select switch
To avoid switch-on plops, it is advised to keep the amplifier
in the mute mode during >100ms (charging of the input
capacitors at pin 1 and pin13).
The circuit in Fig.7 slowly ramps up the voltage at the
mode select switch pin when switching on and results in
fast muting when switching off.
(1) f = 10 kHz.
(2) f = 1 Hz.
(3) f = 100 Hz.
Fig.8 Total harmonic distortion as a function of output power; VP= 14.4V; RL=2Ω.
102
MGA904
10110 1
102
10
1
10
P (W)
o
10 2
1
10 2
THD
(%)
(1)
(2)
(3)