Description

The highly integrated FSBH-series consists of an integrated current-mode Pulse Width Modulator (PWM) and an avalanche-rugged 700V SenseFET. It is specifically designed for high-performance offline Switched-Mode Power Supplies (SMPS) with minimal external components.

The integrated PWM controller features include a proprietary green-mode function that provides off-time modulation to linearly decrease the switching frequency at light-load conditions to minimize standby power consumption. To avoid acoustic-noise problems, the minimum PWM frequency is set above 18kHz. This green-mode function enables the power supply to meet

international power conservation requirements.  The PWM controller is manufactured using the BiCMOS process to further reduce power consumption. The FSBH-series turns off some internal circuits to improve power saving when VFBis lower than 1.6V, which allows an operating current of only 2.5mA.

Features

Brownout Protection with Hysteresis

Built-In 5ms Soft-Start Function

Internal Avalanche-Rugged 700V SenseFET

Low Acoustic Noise During Light-Load Operation

High-Voltage Startup

Linearly Decreasing PWM Frequency to 18KHz

Peak-Current-Mode Control

Cycle-by-Cycle Current Limiting

Leading-Edge Blanking (LEB)

Synchronized Slope Compensation

Internal Open-Loop Protection

VDDUnder-Voltage Lockout (UVLO)

VDDOver-Voltage Protection (OVP)

Internal Auto-Restart Circuit (OVP, OTP)

Constant Power Limit (Full AC Input Range)

Internal OTP Sensor with Hysteresis

Applications

General-purpose switched-mode power supplies and flyback power converters, including:

Auxiliary Power Supply for PC and Server

SMPS for VCR, SVR, STB, DVD & DVCD Player, Printer, Facsimile, and Scanner

Adapter for Camcorder