HFC0100—QUASI RESONANT CONTROLLER
Start
Y
Internal High Voltage
Current Source ON
Vcc Decrease
to 5.5V
N
Vcc<3V?
Shut off the
Switching Pulse
Y
Latch off the
Y
Switching Pulse
Shut Down
Internal High Voltage
Current Source
Y
N
Vcc>11.8V
OTP=
Logic
High?
N
Y
N
Vcc<8V
OVP=
Logic
High?
Y
N
Soft Start
Thermal
Monitor
Monitor Vcc
Pin VSD
Monitor
Monitor VFB
Vcc<8.5V?
and
Y
Y
OLP=Logic
High
VFB<0.5V
0.5V<VFB<3.7V
VFB>3.7V
N
Continuous
Fault Monitor
Burst Mode
Operation
QR mode Operation
OLP=Logic High
N
N
Y
Toff<7.8uS
UVLO, OTP & OLP are auto restart, OVP
is latch
VFB>0.7V
Y
Release from the latch condition, need to
unplug from the main input .
Constraint
Toff_min≥7.8uS
Figure 12—Control Flow Chart
HFC0100 Rev. 1.01
9/23/2011
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13
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