Diagnostic output, Mode select switch – NXP Semiconductors TDA8560Q User Manual
Page 11
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 k
Ω
MGA708
47
µ
F
10 k
Ω
10 k
Ω
mode
select
switch
VP
Diagnostic output
Special care must be taken in the printed-circuit board
layout to separate pin 12 from pin 1 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
>
100 ms (charging of the input
capacitors at pin 1 and pin 13).
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; V
P
= 14.4 V; R
L
= 2
Ω
.
10
2
MGA904
10
1
10
1
10
2
10
1
10
P (W)
o
10
2
1
10
2
THD
(%)
(1)
(2)
(3)