GENERAL DESCRIPTION

OB2560P 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 at large load

condition and it operates in PWM with frequency

reduction at light/medium load. The chip

consumes very low operation current. It achieves

less than 100mW standby power to meet strict

standby power standard.

OB2560P offers comprehensive protection

coverage with auto-recovery feature including

Cycle-by-Cycle current limiting, VDD over voltage

protection, feedback loop open protection, short

circuit protection, built-in leading edge blanking,

VDD under voltage lockout (UVLO), OTP etc.

OB2560P is offered in DIP8 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

 Integrated 2A 620V MOSFET

 Good dynamic response

 Programmable CV and CC regulation

 Built-in primary winding inductance

compensation

 Programmable cable drop compensation

 No need for control loop compensation

 Audio noise free operation

 Built-in leading edge blanking (LEB)

 Ultra low start-up current (typ. 1uA) and low

operating current (typ. 650uA)

 Comprehensive protection coverage with

auto-recovery

 Precise on-chip OTP

 VDD over voltage protection

 VDD under voltage lockout with

hysteresis (UVLO)

 Cycle-by-Cycle current limiting

 Feedback loop open protection

 Output short circuit protection

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