ncp1396 ON Semiconductor, ncp1396 Datasheet - Page 23

• Manufacturer Part Number: ncp1396
• Description: High Performance Resonant Mode Controller With High And Low Sides Drivers
• Manufacturer: ON Semiconductor

timer has triggered the end of output pulses. In that case, the
V
its stability during the hiccup. A similar situation can arise
if the user selects a more traditional startup method, with
an auxiliary winding. In that case, the V
stops the output pulses whenever it is activated, that is to
Figure 50. At power on, output A is first activated and the frequency slowly decreases via the soft-start capacitor
CC
Figure 50 depicts an auto-recovery situation, where the
level was given by an auxiliary power supply, hence
Figure 51. When the Vcc is too low, all pulses are stopped until Vcc goes back to the startup voltage
V
V
V
V
CC(min)
CC(min)
Timer
CC(on)
Timer
CC(on)
A&B
A&B
SS
FB
SS
FB
0.6 V
0.6 V
4 V
4 V
1 V
1 V
A
A
A
A
B
B
B
B
T
T
CC(min)
SS
SS
Startup Resistor
Vcc from a
Slopes are similar
Fault!
NCP1396A, NCP1396B
comparator
http://onsemi.com
Fault!
23
say, when V
V
resistor and heads toward V
When the voltage reaches V
takes place, involving a soft-start. Figure 51 portrays this
behavior.
CC
Vcc from an auxiliary supply
pin still receives its bias current from the startup
CC
A
A
B
B
falls below 10 V typical. At this time, the
T
SS
Fault is
Released
A
A
CC(on)
B
B
CC(on)
T
SS
via the V
, a standard sequence
CC
capacitor.