AN1376 datasheet(11/35 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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AN1376 APPLICATION NOTE

Figure 8.

The low frequency residual ripple compared with the ripple across C10 (input Elcap) shows an

excellent rejection of the circuit (>80 dB).

MEASUREMENT OF THE RMS CAPACITOR CURRENTS

The tables show the rms currents flowing in the output capacitors at 115Vac and 220Vac, full

load. All the rms currents are within the rating of the capacitor type indicated (Rubycon, YXF

series). This avoids the component overstress that should affect the reliability and/or the ex-

pected lifetime of the SMPS

@ 115Vac: ICAP C1 = 1.02 ARMS

@ 115Vac: ICAP C3 = 1.78 ARMS

@ 115Vac: ICAP C19 = 1.15 ARMS

@ 115Vac: ICAP C18 = 140 mARMS

@ 220Vac: ICAP C1 = 0.7 ARMS

@ 220Vac: ICAP C1 = 1.4 ARMS

@ 220Vac: ICAP C19 = 0.92 ARMS

@ 220Vac: ICAP C18 = 130 mARMS

@115 VAC - 50Hz - LINE FREQUENCY RIPPLE

CH1:

VC10

CH2:

+30 Vout

CH2:

+7 Vout

CH3:

+5 Vout

CH3:

+3.3 Vout

CH4:

+12 Vout

AN1376 Datasheet(PDF) 11 Page - STMicroelectronics