NCP1205DR2G View Datasheet(PDF) - ON Semiconductor

Part Name

Description

Manufacturer

NCP1205DR2G

Single Ended PWM Controller Featuring QR Operation and Soft Frequency Foldback

ON Semiconductor 

HV 1

Demag 2

FB 3

Ct 4

8 VCC

7 Drive

6 Isense

5 GND

PDIP−8

NCP1205

PIN CONNECTIONS

HV 1

14 NC

NC 2

Demag 3

13 VCC

12 Drive

FB 4

Ct 5

OVP 6

NC 7

11 Isense

10 GND

9 NC

8 NC

PDIP−14

HV 1

NC 2

NC 3

Demag 4

FB 5

Ct 6

OVP 7

NC 8

16 NC

15 NC

14 VCC

13 Drive

12 Isense

11 GND

10 NC

9 NC

SOIC−16

PIN FUNCTION DESCRIPTION

Pin No.

PDIP−8 PDIP−14 SOIC−16 Pin Name

1

1

1

HV

Function

Startup rail

2

3

3

4

4

5

4

Demag

Zero primary−current

detection

5

FB

Feedback signal to

control the PWM

6

Ct

Timing capacitor

5

10

11

GND

The IC’s ground

NA

6

7

OVP

Overvoltage input

6

11

12

Isense

The primary−current

sensing pin

7

12

13

Drv

This pin drives the

external switcher

8

13

14

VCC

Powers the IC

1. PDIP−14 has different pinouts. Please see Pin Connections.

2. Pin 2, 7, 8, 9 and 14 are nonconnected on PDIP−14.

3. Pin 2, 3, 8, 9, 10, 15 and 16 are nonconnected on SOIC−16.

Description

Connected to the rectified HV rail, this pin provides a

charging path to VCC bulk capacitor.

This pin ensures the restart of the main switcher when

operating in free−run.

This level modulates the peak current level in free−running

operation and modulates the frequency in VFM operation.

By adding a capacitor from Ct to the ground, the user selects

the minimum/maximum operating frequency.

−

By applying a 2.8 V typical level on this pin, the IC is

permanently latched−off until VCC falls below UVLOL.

This pin senses the primary current via an external shunt

resistor.

The IC is able to deliver or absorb 250 mA peak currents

while delivering a clamped driving signal.

A positive voltage up to 30 V maximum can be applied upon

this pin before the IC stops.

http://onsemi.com

2

Share Link: