GENERAL DESCRIPTION

DP2537X is a high performance offline PWM

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. High Precision

Constant Voltage (CV) and Constant Current (CC)

control are 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.

DP2537X offers comprehensive protection

coverage with auto-recovery features including

Cycle-by-Cycle current limiting, VDD Over Voltage

Protection (VDD OVP), short circuit protection,

built-in leading edge blanking, VDD under voltage

lockout (UVLO), OTP, etc.

High precision constant voltage (CV) and constant

current (CC) can be achieved by DP2537X.

DP2537X is offered in SOP7 package.

FEATURES

■ ± 5% Constant Voltage Regulation and

Current Regulation at Universal AC Input

■ Primary Side Regulation (PSR) Without TL431

and Opto-coupler

■ No Need for Control Loop Compensation

■ Programmable CV and CC Regulation

■ Multi-Mode PWM/PFM Operation

■ Output Short Load Protection

■ Less than 75mW Standby Power

■ Built-in Line Voltage and Primary Winding

Inductance Compensation

■ Built-in Adaptive Current Peak Regulation

■ Programmable Cable Drop Compensation

■ Audio Noise Free Operation

■ Built-in Over Temperature Protection (OTP)

■ Soft Gate Driver for Good EMI Performance

■ Built-in Leading Edge Blanking (LEB)

■ Cycle-by-Cycle Current Limiting

■ VDD Under Voltage Lockout with Hysteresis

(UVLO)

■ VDD OVP & Clamp

APPLICATIONS

Low Power AC/DC offline SMPS for

■ Cell Phone Charger

■ Digital Camera Charger

■ Small Power Adapter

■ Auxiliary Power for PC, TV etc.

■ Linear Regulator/RCC Replacement