AN1376 datasheet(18/35 Pages) STMICROELECTRONICS

Part #	AN1376

Description	25W QUASI-RESONANT FLYBACK CONVERTER FOR

PDF	35 Pages

Scroll/Zoom	100%

Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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18 / 35 page

AN1376 APPLICATION NOTE

18/35

As expected the circuit protects itself as well. The secondary peak current is obviously lower,

due to the higher circuit impedance.

Figure 18. 3V3 OUTPUT: SHORT C1

Like the previous output voltage the controller keeps under control the circuit preventing in all

conditions the circuit from catastrophic failures. This happens even shorting the output by the

active load.

Figure 19. 12V OUTPUT: SHORT C19

Even the 12V output is well protected against shorts, either by a power switch or by the active

load

@85 VAC

@265 VAC

CH1:

DRAIN VOLTAGE

CH1:

DRAIN VOLTAGE

CH2:

VC11 (Vaux)

CH2:

VC11 (Vaux)

CH4:

ISHORT CIRCUIT

CH4:

ISHORT CIRCUIT

@85 VAC

@265 VAC

CH1:

DRAIN VOLTAGE

CH1:

DRAIN VOLTAGE

CH2:

VC11 (Vaux)

CH2:

VC11 (Vaux)

CH4:

ISHORT CIRCUIT

CH4:

ISHORT CIRCUIT

AN1376 Datasheet(PDF) 18 Page - STMicroelectronics