FSL127H Datasheet, PDF (1/15 Pages) Fairchild Semiconductor – Green Mode Fairchild Power Switch

September 2010
FSL127H
Green Mode Fairchild Power Switch (FPS™)
Features
ƒ Built-in 5ms Soft-Start Function
ƒ Internal Avalanche-Rugged 700V SenseFET
ƒ Low Audio Noise
ƒ High-Voltage Startup
ƒ Fixed PWM Frequency at 100KHz
ƒ Linearly Decreasing PWM Frequency to 18KHz
ƒ Peak-Current-Mode Control
ƒ Cycle-by-Cycle Current Limiting
ƒ Leading-Edge Blanking (LEB)
ƒ Synchronized Slope Compensation
ƒ Internal Open-Loop Protection (OLP)
ƒ VDD Under-Voltage Lockout (UVLO)
ƒ VDD Over-Voltage Protection (OVP)
ƒ Constant Power Limit (Full AC Input Range)
ƒ Internal OTP Sensor with Hysteresis
Applications
General-purpose switch-mode power supplies and
flyback power converters, including:
ƒ SMPS for VCR, SVR, STB, DVD & VCD Player,
Printer, Facsimile, & Scanner
ƒ Adapter for Camcorder
Description
The highly integrated FSL127H consists of a current
mode Pulse Width Modulator (PWM) and an avalanche-
rugged 700V SenseFET. It is specifically designed for
high-performance offline Switch 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. With the
internal high-voltage startup circuitry, the power loss
due to bleeding resistors is also eliminated. To further
reduce power consumption, the PWM controller is
manufactured using the BiCMOS process, which allows
an operating current of only 3.5mA.
The FSL127H built-in synchronized slope compensation
achieves stable peak-current-mode control. The
proprietary external line compensation ensures
constant output power limit over a wide AC input
voltage range, from 90VAC to 264VAC.
The FSL127H 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-circuit failure occurs. PWM
output is disabled until VDD drops below the UVLO lower
limit, when the controller starts up again. As long as VDD
exceeds ~28V, the internal OVP circuit is triggered.
Compared to a discrete MOSFET and controller or RCC
switching converter solution, the FSL127H reduces total
component count, design size, and weight while
increasing efficiency, productivity, and system reliability.
These devices provide a basic platform well suited for
design of cost-effective flyback converters.
Ordering Information
Part Number SenseFET
FSL127HNY 2.0A 700V
Operating
Temperature Range
Package
Packing Method
-40°C to +105°C
8-Pin Dual In-Line Package (MDIP),
JEDEC MS-001, .300" Wide
Tube
© 2010 Fairchild Semiconductor Corporation
FSL127H • Rev. 1.0.2
www.fairchildsemi.com