AN4346 datasheet(23/33 Pages) STMICROELECTRONICS

No. de pieza	AN4346

Descripción Electrónicos	10 W wide range - high power factor - isolated LED driver using HVLED815PF

PDF	33 Pages

Scroll/Zoom	100%

Fabricante Electrónico	STMICROELECTRONICS [STMicroelectronics]

Página de inicio	http://www.st.com

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DocID025107 Rev 1

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AN4346

Electrical waveform

3.2

Transition mode operation

During ON-time, the peak drain current is modulated by a signal proportional to the ILED pin.

This reference sets the turn-off of the MOSFET.

The MOSFET turn-on depends on the DMG signal that senses demagnetization of the drain

current realizing a transition mode operation.

A primary inductance of 1.5 mH has been selected in order to obtain the converter switching

frequency into the interval [45 - 90] kHz.

Figure 26. ILED pin operation at 100 Vac - 50 Hz Figure 27. Transition mode operation at 100 Vac

- 50 Hz - zoom on the peak - fsw = 51 kHz

CH1: DRAIN pin

CH2: CS pin

CH3: ILED pin

CH4: DMG pin

CH1: DRAIN pin

CH2: CS pin

CH3: ILED pin

CH4: DMG pin

Figure 28. ILED pin operation at 230 Vac - 50 Hz Figure 29. Transition mode operation at 230 Vac

- 50 Hz - zoom on the peak - fsw = 83 kHz

CH1: DRAIN pin

CH2: CS pin

CH3: ILED pin

CH4: DMG pin

CH1: DRAIN pin

CH2: CS pin

CH3: ILED pin

CH4: DMG pin

AN4346 Datasheet(PDF) 23 Page - STMicroelectronics