Specifications For The Protection Circuits For The Digital Amplifier - Pioneer XC-Z9 Service Manual

1
5.7 SPECIFICATIONS FOR THE PROTECTION CIRCUITS FOR THE DIGITAL
QQ
AMPLIFIER
3 7 63 1515 0
The protection circuits for the Digital Amplifier are activated, following the specifications shown below. The error indication on
A
the FL display shows the reason a protection circuit was activated.
Upon diagnosis of the Digital Amplifier, refer to the specifications for the protection circuits here and the overview of the Digital
Amplifier circuitry.
1. Overview
The system microcomputer monitors the ports for shutdown requests (Pin 5 : /SD) and the ports for abnormal-temperature
detection (Pin 2 : /OTW) of the Power Stage ICs (IC3201/IC3301). As soon as any abnormality is detected, it shuts the unit
down.
To notify the user of the possibility of a too high a volume, when the unit is turned on the next time, the volume level will be set
to 0, and an error message will be displayed on the FL display.
B
2. Ports on the system microcomputer to be used for detection
Pin 75: SHUTDOWN
Low voltage at this pin means overcurrent at the Power Stage ICs or that the power supply voltage for the gate
drive for the Power Stage ICs, i.e., VS+12 is less than 10V.
Pin 69: XOTW
Low voltage at this pin means the temperature at the Power Stage ICs exceeded 125°C.
3. Detection timing
C
Start : 500 ms after transmission of reset data to the TAS5504 begins (to compensate for the reset data transmission
time of 500 ms).
Finish : When the STANDBY/ON key is pressed again (when the power-off process starts).
TE
L 13942296513
4. Operation of the protection circuits
The following three protection circuits are activated when the conditions shown below are met:
Overcurrent detection:
Conditions: If the SHUTDOWN ports, which are monitored every 10 ms, become low 7 times in succession.
D
Abnormal temperature detection 1:
Conditions: If the XOTW ports, which are monitored every 10 ms, become low in succession for one minute.
Abnormal temperature detection 2:
(Prerequisite: The XOTW ports, which are monitored every 10 ms, become low three times in succession.)
Conditions: The above prerequisite is upheld, and the conditions for an overcurrent detection are met.
5. Process when the protection circuits are activated
The unit is shut down within 30 ms after abnormality detection then the volume level is set to 0. The unit can be turned on
E
immediately after the shutdown.
www
F
34
1
http://www.xiaoyu163.com
2
x ao
y
. i
2
http://www.xiaoyu163.com
3
8
Q Q
3 6 7 1 3
u163
.
XC-Z9
3
4
2 9 9 4 2 8
1 5 0 5 8 2 9 9 4
m
co
4
9 9
2 8 9 9