FSBH0F70WA Datasheet, PDF (1/14 Pages) Fairchild Semiconductor – Green Mode Fairchild Power Switch (FPS™)

June 2012
FSBH0F70WA, FSBH0170W, FSBH0270W
Green Mode Fairchild Power Switch (FPS™)
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
 V_DD Under-Voltage Lockout (UVLO)
 V_DD Over-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
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 V_FB is lower than 1.6V, which allows
an operating current of only 2.5mA.
The FSBH-series has built-in synchronized slope
compensation to achieve stable peak-current-mode
control. The proprietary external line compensation
ensures constant output power limit over a wide AC
input voltage range, from 90V_AC to 264V_AC.
The FSBH-series provides many protection functions. In
addition to cycle-by-cycle current limiting, the internal
open-loop protection circuit ensures safety when an
open-loop or output short occurs. PWM output is
disabled until V_DD drops below the V_TH-OLP, then the
controller starts up again. As long as V_DD exceeds 28V,
the internal OVP circuit is triggered.
Compared with a discrete MOSFET and controller or
RCC switching converter solution, the FSBH-series
reduces component count, design size, and weight;
while increasing efficiency, productivity, and system
reliability. These devices provide a basic platform that is
well suited for the design of cost-effective flyback
converters, such as in PC auxiliary power supplies.
© 2011 Fairchild Semiconductor Corporation
FSBH0F70WA/0170W/0270W • Rev. 1.0.2
www.fairchildsemi.com