VIPER38HE datasheet(19/31 Pages) STMICROELECTRONICS

Part #	VIPER38HE

Description	VIPerPlus family: peak power high-voltage converter

PDF	31 Pages

Scroll/Zoom	100%

Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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19 / 31 page

DocID025703 Rev 2

19/31

VIPER38

Operation

Where:

•

VOVP is the OVP threshold (see Table 8: Controller section)

•

VOUT OVP is the converter output voltage value to activate the OVP set by the designer

•

NAUX is the number of the auxiliary winding turns

•

NSEC is the number of the secondary winding turns

•

VDSEC is the secondary diode forward voltage

•

VDAUX is the auxiliary diode forward voltage

•

ROVP together with RLIM constitute the output voltage divider

Then, fixing RLIM according to the desired IDlim, the ROVP can be calculated by:

Equation 4

The resistor values will be such that the current sourced and sunk by the CONT pin are

within the rated capability of the internal clamp.

Figure 21. OVP timing diagram

OVP

LIM

OVP

–

OVP

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VIPER38HE Datasheet(PDF) 19 Page - STMicroelectronics