General Description

In order to enhance the efficiency performance, the

LD5523D2 integrates the multi-mode PWM controller, which

consists of Quasi-Resonant (QR) PWM control for light load

condition and Continue Conduction Mode (CCM) for heavy

load condition. Moreover, the QR controller gains the system

performance, but also brings the worse EMI capability,

especially at boundary mode in heavy load. While the

frequency swapping function of LD5523D2 can reduce the

EMI emission of SMPS and helps the power circuit designers

to simply deal with EMI filter and saves several component

and developing time.

The LD5523D2 is implemented in SOT-26 package, and

includes the comprehensive protection function, such as

Over Load Protection (OLP), Over Voltage Protection (OVP),

Output Short Circuit Protection (OSCP) and adjustable Over

Temperature Protection (CS_OTP). Furthermore, the

programmable brown-in/out protection is built-in.

Features

 PSR CCM+QR Multi-Mode Control.

 Frequency Swapping for better EMI performance

 Low Startup Current (<1.5A)

 Built-in load regulation compensation

 65 kHz PWM switching frequency.

 Current mode control with cycle-by-cycle current limit

 UVLO (Under Voltage Lock Out)

 LEB (Leading-Edge Blanking) on CS pin

 VCC & FB Over Voltage Protection

 Adjustable Brown in/out on FB pin.

 External OTP (Over Temperature Protection) on CS Pin

 Internal OTP (Over Temperature Protection)

 Gate Source/Sink Capability: 40mA/-170mA @ output

pin with 1nF capacitor.

Applications

 Networking power supply

 Lower Power AC/DC Adaptor