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Philips Semiconductors
User Manual of High-End RDS/EON
Car Radio System CCR612 (V0.3)
Application Note
96029
The following events must bring the voltage stabilizer in reset state:
Main power supplied
Ignition or static on/off switch closed
Power key pressed
Power voltage is OK again after an engine start
The reset pulse for the microcontroller must be at least 20 msec. wide, measured at the threshold level
(max. 3.5 V).
After the end of the reset pulse the power key is sensed and the "KEYB0" output is pulled low to keep the
stabilizer into the reset mode.
When the radio should stay on, (see switching on and off, paragraph 6.1), the "ON" output is pulled low
after the check of the option diodes and when the power key is released.
After approximately 400 msec., the microcontroller tests the HOLD input. If it is low, something is wrong
and the set is switched off, but internally a reset will be generated and the set will try to switch on again.
Else it is continuously monitored for supply voltage failure e.g. starting the cars engine.
KEYB0
CCR612S
HOLD
Vdd
25
18
HOLD
Vreg3
RESET
ON
RESET
IGN
Vss
TDA3602
Power
Stabilizer
State
Control
GND
Vreg2
Vreg1
Vbu
Vp
VS1 +8.5V
VS2 +5V
1
4
7
5
8
2
9
3
6
36
4
30
BATTERY
Ignition Contact or
static on/off
switch
VS3 +5V
standby
POWER
key
33k
47µ
680µ
47µ
47µ
7.5A
160µ H
2200µ
100k
100k
120k
120k
47k
4V7
100n/
for static
on/off swiitch 10µ
470n
10k
T1
T2
22k
D1
Vsc
C1
47n
C2
1µ
47n
1k
470n
47k
47k
47n
4k7
Figure 8 Interface with TDA3602 Power stabilizer
Note,
The power key is a momentary push-button, closed only as long as it is pressed down.
43