1

Pin connections and function

Figure 2. Connection diagram (top view)

Table 1. Pin function

Pin N.

Name

Function

1,2,3,4,

GND

Device ground for current return.

5

BR

Input brown-in and brown-out protection. A 10 nF capacitor between this pin and GND is required. If

the feature is not used, the pin must be connected to GND.

6

iOVP

Input OVP protection. If the feature is not required, the pin must be connected to GND.

7

N.A.

Not available for user. This pin is mechanically connected to the controller die pad of the frame. In order

to improve noise immunity it must be connected to GND.

8

HV

Start-up pin. Connect to the main through a resistor to provide the bias to the HV start-up generator. It

is also used as upper resistor to set the BR and iOVP functions. Select a value in the range 10-30 MΩ to

minimize the residual consumptions.

A 220 pF ceramic capacitor must be connected between this pin and GND for proper functionality of high

voltage start-up control logic.

9

TB

Blanking time adjustment and valley synchronization. During on-time, a resistor connected between

TB and the auxiliary winding increases the blanking time proportionally to the input voltage, to reduce the

switching losses at high line.

During off-time, a voltage divider connected among auxiliary winding, TB and GND allows adjusting the

turn-on delay time after demagnetization, to precisely synchronize the GaN turn-on with the valley of the

resonance.

Connect the pin to GND if both functions are not used.

10

FB

Feedback. This pin is used to set the peak current value required by the control loop for a given output

load.

The pin is the input for the optocoupler. A level 100 mV below the threshold VFBB activates the burst-

mode operation. A level close to the threshold VFBH approaches the cycle-by-cycle overcurrent set point.

11

ZCD

ZCD. Transformer's demagnetization sensing for quasi-resonant operation.

A voltage divider must be connected among auxiliary winding, ZCD and GND. A negative-going edge

across the pin triggers GAN turn-on.

VIPERGAN65

Pin connections and function

DS14005 - Rev 2

page 2/35