NCP1339

www.onsemi.com

3

PIN FUNCTION DESCRIPTION

Pin

Number

Pin

Name

Function

1

X2

When the voltage on this pin disappears, the controller ensures the X2−capacitors discharge.

2

REM

The part operates when the REM pin is forced lower than a certain level and enters the Power Savings

Mode (PSM) otherwise.

3

OPP

A resistive divider from the auxiliary winding to this pin sets the OPP compensation level.

4

ZCD

Input to the demagnetization detection comparator for the QR Flyback controller.

5

Fault

The controller enters fault mode if the voltage of this pin is pulled above or below the fault thresholds. A pre-

cise pull up current source allows direct interface with an NTC thermistor. Fault detection triggers a latch.

6

FB

Feedback input for the QR Flyback controller. Allows direct connection to an optocoupler.

7

CS

Input to the cycle−by−cycle current limit comparator for the QR Flyback section.

8

GND

Ground reference.

9

DRV

This is the drive pin of the circuit. The DRV high−current capability (−0.5 /+0.8 A) makes it suitable to effec-

tively drive high gate charge power MOSFETs.

10

VCC

comparator monitors this pin and offers a means to latch the converter in fault conditions.

11

NC

12

NC

13

Removed for creepage distance.

14

HV

This pin provides a charging current during start−up and auto−recovery faults but also a means to efficiently

discharge the input X2 capacitors.