VIPER35 datasheet(37/44 Pages) STMICROELECTRONICS

Part #	VIPER35

Description	Quasi-resonant high performance off line high voltage converter

PDF	44 Pages

Scroll/Zoom	100%

Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

Logo

37 / 44 page

DocID026980 Rev 4

37/44

VIPer35

Operation description

Figure 43. Brown

-out: external setting and timing diagram

VINon must be less than the peak voltage at minimum mains and VINoff voltage has to be

less than the minimum voltage on the input bulk capacitor at minimum mains and maximum

load.

BR pin is a high impedance input connected to high value resistors, thus it is ready to pick

up noise, which might alter the VINoff threshold when the converter operates or causes the

undesired switch-off of the device during ESD tests.

The pin ca be bypassed to ground with a small film capacitor (1-10 nF) to prevent any

malfunctioning.

If the brown-out function is not used, BR pin has to be connected to GND, ensuring that the

voltage is lower than the minimum VDIS threshold (50 mV, see Table 7). In order to enable

the brown-out function, BR pin voltage has to be higher than the maximum VDIS threshold

(150 mV, see Table 7).

VIPER35 Datasheet(PDF) 37 Page - STMicroelectronics