RS2122A

High Precision CC/CV PSR PWM Switch

Tel: 886-2-66296288

‧Fax: 886-2-29174598‧ http://www.princeton.com.tw‧2F, No. 233-1, Baociao Rd., Sindian Dist., New Taipei City 23145, Taiwan

DESCRIPTION

RS2122A is a high performance offline PSR controller

for

low

power

AC/DC

charger

and

adapter

applications. It operates in primary-side sensing and

regulation, so opto-coupler and TL431 could be

eliminated. In CC control, the current and output

power setting can be adjusted externally by the sense

are utilized to achieve high performance and high

efficiency. In addition, good load regulation is

achieved by the built-in cable drop compensation.

The chip consumes very low operation current (typical

650μA), it can achieve less than 30mW standby

power to meet strict standby power standard.

RS2122A offers comprehensive protection coverage

with auto-recovery features including Cycle-by-Cycle

current

limiting,

VDD

over

voltage

protection,

feedback loop open protection, CS open protection,

Output short circuit protection, built-in leading edge

blanking, VDD under voltage lockout (UVLO), Over

temperature protection, etc. RS2122A is offered in

SOP-7L package.

APPLICATIONS

 Switching AC/DC Small Power Adaptor

 Cell Phone or Digital Cameras Charger

 Auxiliary Power for PC, TV etc

 Linear Regulator/RCC Replacement

FEATURES

 Low startup current

 ±4% CC and ±5% CV Precision

 Primary-side Sensing and Regulation Without TL431

and Opto-coupler

 High precision constant voltage and current regulation

at universal AC input

 Programmable CV and CC Regulation

 Built-in Primary winding inductance compensation

 Programmable Cable Drop Compensation

 Built-in Feedback Loop Open Protection

 Built-in CS Open Protection

 VDD Over Voltage Protection

 Built-in Output Short Circuit Protection

 Built-in Leading Edge Blanking (LEB)

 Over temperature protection(OTP)

 Cycle-by-Cycle Current Limiting

 VDD Under Voltage Lockout with Hysteresis (UVLO)

 SOP-7L green Packaging

BLOCK DIAGRAM

VDD

VDD OVP

Output OVP

CC Control

DEM

Drop comp

FB

FB Short

Protection

Output Short

Protection

Sample

Compensation

Network

CV Control

PWM Model

PFM Model

2V

Soft Start

LEB

CS

0.5V

CS Floating

Protection

R

S

Q

BJT Base

Driver

LD

LOGIC

POR

GND