VIPER38LE datasheet(15/31 Pages) STMICROELECTRONICS

Teilenummer	VIPER38LE

Bauteilbeschribung	VIPerPlus family: peak power high-voltage converter

PDF	31 Pages

Scroll/Zoom	100%

Hersteller	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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15 / 31 page

DocID025703 Rev 2

15/31

VIPER38

Operation

The following formula can be used for the CVDD capacitor calculation:

Equation 1

The parameter tSSaux is the time needed for the steady state of the auxiliary voltage. This

time represents an estimate of the user’s application according to the output stage

configurations (transformer, output capacitances, etc.).

During the converter startup time, the drain current limitation is progressively increased to

the maximum value. In this way the stress on the secondary diode is considerably reduced.

It also helps to prevent transformer saturation. The soft-start time lasts 8.5 ms and the

feature is implemented for every attempt of the startup converter or after a fault.

Figure 17. IDD current during startup and burst mode

VDD

DDch1

SSaux

DDon

DDoff

–

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VIPER38LE Datenblatt(PDF) 15 Page - STMicroelectronics