Fairchild FSL206MR5W auxiliary power supply solution

The FSL206MR integrated Pulse-Width Modulator (PWM) and SenseFET is specifically designed for high performance offline Switched-Mode Power Supplies (SMPS) with minimal external components. The internal SenseFET withstands 650V, has a fixed operating frequency of 67kHz, and has a no-load power consumption of less than 150mW at 265VAC without bias winding. It has multiple protections and is mainly used in switching power supplies and auxiliary power supplies for STB, DVD and DVCD players. This article introduces the main features, block diagram, typical application circuit diagram of the FSL206MR, as well as the main indicators, circuit diagram, bill of materials and PCB layout diagram of the FSL206MR 5W evaluation board.

The FSL206MR integrated Pulse-Width Modulator (PWM) and SenseFET is specifically designed for high performance offline Switched-Mode Power Supplies (SMPS) with minimal external components. This device integrates high-voltage power regulators that combine an avalanche-rugged SenseFET with a Current-Mode PWM control block.

The integrated PWM controller includes: 7.8V regulator for no bias winding, Under-Voltage Lockout (UVLO) protection, Leading-Edge Blanking (LEB), an optimized gate turn-on/turn-off driver, EMI attenuator, Thermal Shutdown (TSD) protection, temperature-compensated precision current sources for loop compensation, and fault-protection circuitry such as; Overload Protection (OLP), Over-Voltage Protection (OVP), Abnormal Over-Current Protection (AOCP), and Line Under-Voltage Protection (LUVP). During startup, the FSL 206MR offers good soft-start performance.

The internal high-voltage startup switch and the Burst-Mode operation with very low operating current reduce the power loss in Standby Mode. As a result, it is possible to reach power loss of 150mW with no-bias winding and 25mW (for FSL206MRBN) with bias winding at no-load condition when the input voltage is 265VAC.

Main features:

Internal Avalanche-Rugged SenseFET: 650V

Precision Fixed Operating Frequency: 67kHz

No-Load <150mW at 265VAC without Bias Winding;<25mW with Bias Winding for FSL206MR, <30mW with Bias Winding for FSL206MRBN

No Need for Auxiliary Bias Winding

Frequency Modulation for Attenuating EMI

Line Under-Voltage Protection (LUVP)

P ulse-by-Pulse Current Limiting

Low Under-Voltage Lockout (UVLO)

Ultra-Low Operating Current: 300A

Built-In Soft-Start and Startup Circuit

Various Protections: Overload Protection (OLP), Over-Voltage Protection (OVP), Thermal Shutdown (TSD), Abnormal Over-Current Protection (AOCP) Auto-Restart Mode for All Protections

FSL206MR Applications:

SMPS for STB, DVD, and DVCD Player

SM PS for Auxiliary Power

Figure 1. FSL206MR block diagram

Figure 2. FSL206MR typical application circuit diagram

FSL206MR 5W evaluation board

5W power supply main indicators:



Figure 3. FSL206MR 5W evaluation board appearance Figure

4. FSL206MR 5W evaluation board circuit diagram
FSL206MR 5W evaluation board bill of materials:


Figure 5. FSL206MR 5W evaluation board PCB layout (top layer)

Figure 6. FSL206MR 5W evaluation board PCB layout (bottom layer)
For details, please see:
http://www.fairchildsemi.com/ds/FS/FSL206MR.pdf
and
http://www.fairchildsemi.com/products/evaluationboards/FEBFSL206MRN_H428v1e.pdf?user-guide=