AN4314 datasheet(17/31 Pages) STMICROELECTRONICS

Part #	AN4314

Description	25 W wide-range high power factor buck-boost converter demonstration board using the L6564H

PDF	31 Pages

Scroll/Zoom	100%

Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

Logo

17 / 31 page

DocID024821 Rev 2

17/31

AN4314

PFC waveforms

5.2

Transition mode operation

The ZCD pin, GD and CS pin have also been checked in order to show transition mode

operation

Figure 10 and Figure 11.

An inductor value of 680 μH has been selected in order to get the converter to operate at

very low frequency (35 kHz at 100 V

), minimizing the EMI filter and optimizing the power

factor.

Turn-on of the MOSFET depends on the ZCD triggering signal during its falling edge, turn-

off depends on the CS signal and its comparison with the internal feedback signal (MULT x

COMP).

5.3

Startup

With a 33 μF capacitor on the V

pin, the L6564H turns on typically in less than 600 ms

and the LED light appears 100 ms later. The turn-on time of the device depends on the

value of the V

capacitor and the charging current of the HVS, according to the following

equation (L6564H datasheet [

3]):

Equation 5

Figure 10. TM operation at 100 Vac - 0.35 A -

fsw = 35 kHz

Figure 11. TM operation at 230 Vac - 0.35 A-

fsw = 50 kHz

CH1: DRAIN

CH2: GD

CH3: ZCD

CH4: CS

AM13770V1

CH1: DRAIN

CH2: GD

CH3: ZCD

CH4: CS

AM13771V1

turn

VCC

start

arg

−

⋅

AN4314 Datasheet(PDF) 17 Page - STMicroelectronics

AN4314 Datasheet(HTML) 17 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

Datasheet Download

Link URL