VIPER115XSTR datasheet(4/37 Pages) STMICROELECTRONICS

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Pin setting

VIPer11

4/37

DS11873 Rev 5

Pin setting

Figure 2. Connection diagram

Table 1. Pin description

SSOP10

Name

Function

GND

Ground and MOSFET source. Connection of source of the internal MOSFET

and the return of the bias current of the device. All groundings of bias

components must be tied to a trace going to this pin and kept separate from the

pulsed current return.

VCC

Controller supply. An external storage capacitor has to be connected across

this pin and GND. The pin, internally connected to the high voltage current

source, provides the VCC capacitor charging current at startup. A small bypass

capacitor (0.1

F typ.) in parallel, placed as close as possible to the IC, is also

recommended, for noise filtering purpose.

DIS

Disable. If its voltage exceeds the internal threshold VDIS_th (1.2 V typ.) for

more than tDEB time (1 ms, typ.), the PWM is disabled for tDIS_RESTART

(500msec, typ.) in auto-restart mode, resuming normal operation as soon as

VDIS falls below VDIS_th. An input overvoltage protection can be built by

connecting a voltage divider between the DIS pin and the rectified mains. In

case of non-isolated topologies, with the same principle an output overvoltage

protection can be implemented. If the disable function is not required, the DIS

pin must be soldered to GND, which excludes the function.

4FB

Direct feedback. It is the inverting input of the internal transconductance E/A,

which is internally referenced to 1.2 V with respect to GND. In case of non-

isolated converter, the output voltage information is directly fed into the pin

through a voltage divider. In case of primary regulation, the FB voltage divider is

connected to the VCC. The E/A is disabled soldering FB to GND.

VIPER115XSTR Datasheet(PDF) 4 Page - STMicroelectronics