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 75mW 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.
Figure.1. Typical CC/CV Curve
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