NCP1396B ON Semiconductor, NCP1396B Datasheet - Page 23

• Manufacturer Part Number: NCP1396B
• Description: High Performance Resonant Mode Controller featuring High-voltage Drivers
• Manufacturer: ON Semiconductor

Figure 49 depicts an auto-recovery situation, where the
timer has triggered the end of output pulses. In that case,
the Vcc level was given by an auxiliary power supply,
hence 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
VCC(min) comparator stops the output pulses whenever it
Figure 49. At power on, output A is first activated and the frequency slowly decreases via the soft-start capacitor
NCP1396A, NCP1396B
http://onsemi.com
23
is activated, that is to say, when Vcc falls below 10V
typical. At this time, the Vcc pin still receives its bias
current from the startup resistor and heads toward VCC
via the Vcc capacitor. When the voltage reaches VCC
a standard sequence takes place, involving a soft-start.
Figure 50 portrays this behavior.
ON
ON
,