Product Description

PL3378 is a high efficiency Primary Side Regulator and

highly integrated PWM Power Switch for AC/DC power

supply applications. It simplifies conventional CC/CV

charger/adaptor designs by eliminating the opto-coupler

and secondary control circuitry. Constant output voltage

and current regulation is realized as shown in the Fig.1

below. Multi-mode operations are utilized to achieve low standby

power, high efficiency and audio & noise free. PL3378

operates in PFM mode at large load condition, with the

load becomes medium or light, the chip operates in Green

mode to achieve high efficiency. PL3378 also offers rich protection features including

Cycle-by-Cycle peak current limiting, UVLO, OTP, load

OVP, and VDD over voltage.

Key Features

• Built-in Integrated Power BJT• Accurate Constant Current

Regulation at Universal ACinput • Eliminates Opto-coupler andall

Secondary CC/CV Control Circuitry• Built-in Line Compensationfor

Tighter CC/CV Regulation

• Built-in Compensation for

Transformer Inductance

Tolerances

• Adjustable Output Cable

Compensation

• Adaptive Multi-mode PFMControl for Improving Efficiency• Low Start-up Current • Built-in Leading Edge Blanking(LEB) • Cycle-by-Cycle Current Limiting• VDD Under Voltage Lockout andVDD over voltage protection• Built-in Short Circuit ProtectionandOutput Overvoltage Protection• Over temperature protection

Applications

AC/DC power supply applications• Cell Phone Charger • Small Power Adaptor/Charger • LED Driver • Standby Supply for Consumer

Electronics