STC6105 Datasheet, PDF (10/10 Pages) Suntac Electronic Corp. – Power Supply Supervisor + Regulator + PWM

Product Specification
STC6105 Power Supply Supervisor + Regulator + PWM
PWM switching signal in the secondary power
transformer is proportional to the AC line voltage. Adjust
the ratio of resistor divider to decide the threshold of
power-down warning. A small capacitor is connected
from UVAC to ground for filtering the switching noise.
VS
Vo
Vin
R1
R2
C1
+
0.7V
UVAC
Negative Voltage Protection
The NVP provides an UVP (under voltage protection)
for negative voltage outputs. An under-voltage represents
the phenomenal of the overload condition in negative
voltage output. For example, the –12V output may drop
to –10V during the overload situation. A resistor
determining the threshold of the protection is connected
from pin NVP to the negative voltage output. Via this
resistor, NVP outputs a 64uA constant current to the
negative voltage output. When the NVP voltage is over
2.1V and the situation kept for longer than 7 msec,
STC6105 will lock the power outputs off.
VNVP = 64 uA u (R1 + R2) – V-12V
Over Power Protection (OPP)
The OPP (over power protection) is used for
detecting over power and/or short-circuit conditions.
When OPPS voltage (p.4, Note-1) is higher than 2.1V and
this situation existed for longer than 7 msec,STC6105 will
pull the PG low and lock off the power outputs.
The power outputs will be locked off when VNVP t
2.1V.
64uA
R1
R2
-12V
OP1
2.1V
-5V
Vdd
R1
R2
OP2
OPP
C1
R3
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