Features

High-Voltage CMOS Process with Excellent ESD

protection

Very Low Startup Current (<20μA)

Current Mode Control

Non-audible-noise Green Mode Control

UVLO (Under Voltage Lockout)

LEB (Leading-Edge Blanking) on CS Pin

Programmable Switching Frequency

Internal Trembling (±4KHz)

Internal Slope Compensation

OVP (Over Voltage Protection) on Vcc Pin

OLP (Over Load Protection)

300mA Driving Capability

Applications

Switching AC/DC Adaptor and Battery Charger

Open Frame Switching Power Supply

General Description

The LD7531 is built-in with several functions, protection and

EMI-improved solution in a SOT-26/ DIP-8 package. It takes

less components counts or circuit space, especially ideal for

those total solutions of low cost.

The implemented functions include low startup current,

green-mode power-saving operation, leading-edge blanking

of the current sensing and internal slope compensation.

And the LD7531 features more protections like OLP (Over

Load Protection) and OVP (Over Voltage Protection) to

prevent the circuit damage from the abnormal conditions.

Furthermore, the frequency trembling function is to reduce

the noise level and thus helps the power circuit designers to

easily deal with the EMI filter design by using minimum

component cost and developing time.