GENERAL DESCRIPTION

OB2513x is a high performance offline PSR power

switch for low power AC/DC charger and adapter

applications. It operates in primary-side sensing

and regulation. Consequently, opto-coupler and

TL431 could be eliminated. Proprietary Constant

Voltage (CV) and Constant Current (CC) control is

integrated as shown in the figure below.

In CC control, the current and output power setting

can be adjusted externally by the sense resistor

Rs at CS pin. In CV control, multi-mode operations

are utilized to achieve high performance and high

efficiency. In addition, good load regulation is

achieved by the built-in cable drop compensation.

Device operates in PFM in CC mode as well at

large load condition and it operates in PWM with

frequency reduction at light/medium load. The chip

consumes very low operation current, it can

achieve less than 75mW standby power.

OB2513x offers comprehensive protection

coverage with auto-recovery features including

Cycle-by-Cycle current limiting, VDD over voltage

protection, short circuit protection, built-in leading

edge blanking, VDD under voltage lockout (UVLO),

OTP etc.

OB2513x is offered in SOP7 package

FEATURES

Primary-side sensing and regulation without

TL431 and opto-coupler

High precision constant voltage and current

regulation at universal AC input

Multi-mode PWM/PFM operation for efficiency

improving

Good dynamic response

Programmable CV and CC regulation

Built-in line voltage and primary winding

inductance compensation

Programmable cable drop compensation

No need for control loop compensation

Audio noise free operation

Internal BJT switch

Built-in leading edge blanking (LEB)

Comprehensive protection coverage with

auto-recovery

VDD over voltage protection

VDD under voltage lockout with

hysteresis (UVLO)

Cycle-by-cycle current limiting

Feedback loop open protection

Output short circuit protection

Over temperature protection (OTP)

APPLICATIONS

Low Power AC/DC offline SMPS for

Cell Phone Charger

Digital Cameras Charger

Small Power Adapter

Auxiliary Power for PC, TV etc.

Linear Regulator/RCC Replacement