Pin

number

Name

Function

8

COMP

Compensation. This is the output of the internal E/A. A compensation network is placed between

this pin and GND to achieve stability and good dynamic performance of the control loop. In case of

secondary feedback, the internal E/A must be disabled and the COMP directly driven by the optocoupler

to control the DRAIN peak current setpoint.

9 to 12

N.C.

Not connected. These pins must be left floating in order to get a safe clearance distance.

13 to 16

DRAIN

MOSFET drain. The internal high-voltage current source sources current from these pins to charge

the VCC capacitor at startup. The pins are mechanically connected to the internal metal PAD of the

MOSFET in order to facilitate heat dissipation. On the PCB, some copper areas under these pins

decreases the total junction-to-ambient thermal resistance thus facilitating the power dissipation.

VIPER31

Pin setting

DS13285 - Rev 3

page 3/40