AN3233 datasheet(14/35 Pages) STMICROELECTRONICS

Part #	AN3233

Description	This application note describes the characteristics

PDF	35 Pages

Scroll/Zoom	100%

Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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14 / 35 page

Functional check

AN3233

14/35

Doc ID 17595 Rev 1

Functional check

Steady-state operation

In Figure 7 some waveforms relevant to the resonant stage during steady-state operation

are given. The selected switching frequency is about 120 kHz, in order to have a good trade

off between transformer losses and dimensions. The converter operates slightly above the

resonance frequency.

Figure 8

shows the key signals of SRK2000: each rectifier MOSFET is switched on and off

according to its drain-source voltage which, during conduction time, is the voltage image of

the current flowing through the MOSFET.

Figure 7.

Resonant stage waveforms

at 115 V – 60 Hz – full load

Figure 8.

SRK2000 key signals

at 115 V – 60 Hz – full load

CH1: HB voltage

CH2: CF pin voltage

CH1: GD1 pin voltage

CH2: DVS1 pin

CH4: Res. tank current

CH3: GD2 pin voltage

CH4: DVS2 pin

AN3233 Datasheet(PDF) 14 Page - STMicroelectronics