Dual Output Off-Line Non-isolated Flyback Power Solution
AP3917B 12V/20mA+3.8V20mA EV3 Board User
’s Guide
AP3917B EV3 Page 10 of 17 06-21-2019
Rev 1.0 www.diodes.com
Turn on Waveforms
CH1: Vin; CH2: 3.8V output; CH3:12V output
Fig. 5-5, Start up time is 16.8ms @full load,
85V
/60Hz
Fig 5-6, Start up time is 16.1ms @full load, 115V/60Hz
Fig. 5-7, Start up time is 15.3ms @full load,
230V
/50Hz
Fig 5-8, Start up time is 14.6ms @full load, 265V/50Hz
5.2.2 Voltage Stress
The voltage tested below was between the source and the drain pin of IC. The test need use differential probe. The Vak voltage
is tested between the anode and cathode of flyback diode D2/D3.
Table 5-6, MOSFET drain-source and flyback diodes Vak voltage stress
Input voltage
Voltage stress
figures
Vds(V)
Vak1(V)
Vak2(V)
85V/60Hz
221
17
57
Fig. 19
115V/50Hz
265
21
65
-
230V/50Hz
429
37
119
-
264V/60Hz
484
42
129
Fig. 22