FSL137H: 700V Integrated Power Switch for 19Watt offline flyback converters, 100kHz, Brown In/Out Protection
The highly integrated FSL137H consists of an integrated 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. The 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 FSL137H 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 FSL137H 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 FSL137H 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.
Features
- Built-in 5ms Soft-Start Function
- Internal Avalanche Rugged 700V SenseFET
- Low Audio Noise
- High-Voltage Startup
- Fixed PWM Frequency at 100KHz
- 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 (OLP)
- VDD Under-Voltage Lockout (UVLO)
- VDD Over-Voltage Protection (OVP)
- Constant Power Limit (Full AC Input Range)
- Internal OTP Sensor with Hysteresis
Ordering CodeProduct | Product & Eco Status | Unit Price/1K Order | Packing Method Convention | Package Marking Convention* |
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FSL137HNY | Full Production
Green as of Sep 2009
China RoHS
Restrictions apply. Not to be shipped into the U.S.A. | $1.0465 | MDIP 8L
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RAIL | Line 1$Y (Fairchild logo) &Z (Plant Code) &2 (2-Digit Date Code) &K
Line 2L137H
Line 3NYK
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Application Notes
AN-4138 Design Considerations for Battery Charger Using Green Mode Fairchild Power Switch (FPS™) Last Update : 28-Jun-2014AN-4137 Design Guidelines for Offline Flyback Converters using FPS™ Last Update : 03-Apr-2015AN-4140 Transformer Design Consideration for Offline Flyback Converters Using Fairchild Power Switch (FPS™) Last Update : 28-Jun-2014AN-4141 Troubleshooting and Design Tips for Fairchild Power Switch (FPS™) Flyback Applications Last Update : 28-Jun-2014AN-4148 Audible Noise Reduction Techniques for FPS™ Applications Last Update : 10-Oct-2013AN-9719 Applying Fairchild Power Switch (FPS™) FSL1x7 to Low-Power Supplies Last Update : 26-Nov-2014