AN2929 datasheet(11/32 Pages) STMICROELECTRONICS

Nome de Peças	AN2929

Descrição Electrónicos	In consumer applications such as LCD or plasma TVs

PDF	32 Pages

Scroll/Zoom	100%

Fabricante Electrônico	STMICROELECTRONICS [STMicroelectronics]

Página de início	http://www.st.com

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11 / 32 page

AN2929

Testing the board

Doc ID 15333 Rev 2

11/32

The waveforms of the two voltages (VOUT and VOUT_FLY) are shown in the figures below.

Figure 9.

Output voltage ripple 115 VINAC full load

Figure 10.

Output voltage ripple 230 VINAC full load

When the device is working in burst mode, a lower frequency ripple is present. In this mode

of operation the converter does not supply continuous power to its output. It alternates

periods when the power MOSFET is kept off and no power is processed by the converter,

and periods when the power MOSFET is switching and power flows towards the converter

output. Even if no load is present at the output of the converter, during no switching periods,

the output capacitors are discharged by their leakage currents and by the currents needed

to supply the circuitry of the feedback loop present at the secondary side. During the

Ch3: VOUT

Ch4: VDRAIN

Ch2: VOUT_FLY

Ch3: VOUT

Ch4: VDRAIN

Ch2: VOUT_FLY

AN2929 Folha de dados(PDF) 11 Page - STMicroelectronics