Shivaki STV-24LEDGR7, Service Manual

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D-class power amplifier
R2A15120FA
PRELI
MINAR
Y
some
param
etric lim
its are
subjec
t to ch
ange.
CONFIDENTIAL
(1) Over Current Protection Circuit
This circuit detects the unusual over current of Output Power FETs and protects IC. The detection
current value will be set 7.5A (typ).
(3) Under Voltage Protection Circuit
This circuit detects unusual operation of power supply voltage and protects it.
This function works effective during starting-up or turning-off or temporary decrease in power supply voltage.
It is possible to prevent unusual destruction and to make POP noise minimum.
The detected voltage is the voltage of the terminal DVDD(Typ. 10V).
under voltage detect value : 7.0V typ
under voltage release value: 8.0V typ
(2) Over Temperature Protection Circuit
This circuit detects unusual over temperature of IC(chip) and protects it.
When internal junction temperature reaches to standard temperature (150°C ),
the operation will start. And until temperature falls to the hysteresis condition(30
℃
),
protection circuit will continue to be operated.
Protection Start Temperature: 150°C typ Protection Restore Temperature: 120°C typ
11-9 Protection functions
11-10. ATT function of warning over temperature
This function detects abnormal rising temperature, detects warning before protection action and
makes output amplitude decrease around 3dB.
This ATT would be kept until temperature falls to under 120°C.
Warning over temperature
：
140
℃
typ ATT release temperature
：
120
℃
typ
When above protection circuit(From 1 to 3) is operated, all output FETs be OPEN and output
terminal are connected to GND(VS) by 5k
Ω
pull-down resistor.
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