FAIRCHILD FEB-LO27 User Guide
Summary
This evaluation board provides a complete reference design for developing high-efficiency, universal line voltage T8 LED lamp drivers using the FL7732 controller. The accompanying manual is an indispensable resource for engineers, detailing everything from core schematics and BOMs to advanced performance testing. It covers Power Factor Correction (PFC), constant current regulation characteristics, and detailed EMI/transformer design guidelines—making it the perfect tool for developing robust, compliance-ready LED lighting systems.
Page 1 Text Content
User Guide for
FEB-L027 Evaluation Board
Reference Design Report for a 17.5W T8
LED Lamp Using FL7732
Featured Fairchild Product:
FL7732
Direct questions or comments about this evaluation board to: “Worldwide Direct Support”
Fairchild Semiconductor.com
© 2012 Fairchild Semiconductor Corporation 1 FEB-L027_FL7732 • Rev. 1.0.0
Page Summary Contents For FAIRCHILD FEB-LO27 User Guide
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User Guide for FEB-L027 Evaluation Board Reference Design Report for a 17.5W T8 LED Lamp Using FL7732 Featured Fairchild Product: FL7732 Direct questions or comments about this evaluation board to: “W...
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Table of Contents 1. Introduction ............................................................................................................................... 3 1.1. General Description ..............
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The following user guide supports the evaluation kit for the FL7732. It should be used in conjunction with the FL7732 datasheet as well as Fairchild’s application notes and technical support team. Ple...
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1.3. Internal Block Diagram Figure 1. Block Diagram of FL7732 © 2012 Fairchild Semiconductor Corporation 4 FEB-L027_FL7732 • Rev. 1.0.0
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2. General Specifications for Evaluation Board Table 1. Evaluation Board Specifications for LED Lighting Lamp Description Symbol Value Comments VIN.MIN 90V Minimum Input Voltage Voltage VIN.MAX 265V M...
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3. Evaluation Board Dimensions: 297.81 (L) × 17.14 (W) × 11.00 (H) [mm] Figure 2. Top / Bottom of Evaluation Board Figure 3. PCB Pattern Top / Bottom of Evaluation Board © 2012 Fairchild Semiconductor...
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4. Schematic 5µ /ju 4 1 00KD Figure 4. Evaluation Board Schematic © 2012 Fairchild Semiconductor Corporation 7 FEB-L027_FL7732 • Rev. 1.0.0
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5. Bill of Materials Item Part Part Number Qty. Description Manufacturer No. Reference 1 C1, C2 MPE 400V473K 14S 2 47n F / 400V MPE Film Capacitor Sungho 3 C3 C1206C332KDRACTU 1 3.3n F / 1k V SMD Capa...
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Bill of Materials (Continued) Item Part Part Number Qty. Description Manufacturer No. Reference Fairchild 43 U1 FL7732_F116 1 Main Controller Semiconductor © 2012 Fairchild Semiconductor Corporation 9...
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6. Transformer Design Figure 5. Transformer Bobbin Structure and Pin Configuration Table 2. Electrical Characteristics Pin Specifications Remark Inductance 2 – 1 585µH ± 10% 100k Hz, 0.1V Leakage 2 – ...
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7. Electromagnetic Interference (EMI) Inductor (L1 & L2) Design Figure 6. Transformer Bobbin Structure and Pin Configuration Table 3. Winding Specifications Part Ref. Winding Pin (S F) Wire Turn...
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8. Performance of Evaluation Board 8.1. Test Condition & Equipments Ambient Temperature TA = 25°C AC Power Source: ES2000S by PSTATIONES Power Analyzer: PZ4000 by YOKOGAWA Multi Meter: 2002 by KEI...
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8.2. Startup Startup time is 1.3s (VIN = 90VAC) ~ 330ms (VIN = 265VAC) Figure 7. VIN = 90VAC / 60Hz, Startup Figure 8. VIN = 115VAC / 60Hz Startup Time Time at 10-LED (35V/500m A); C1 [VDD], at 10-LED...
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8.3. Operation Waveforms Output current ripple is under 115m Ap-p with a rated output current of 500m A. Figure 11. VIN= 90VAC / 60Hz, Operation Figure 12. VIN = 115VAC / 60Hz Operation Waveforms at 1...
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8.4. Constant-Current Regulation Constant-current deviation in the wide output voltage range from 5-LED (17.5V) to 10- LED (35V) is less than ±1.82% at each line input voltage. Line regulation is less...
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8.5. Short-LED/ Open-LED Protections In short-LED condition, the OCP level is reduced from 0.7V to 0.2V because the FL7732 lowers the OCP level when the VS voltage is less than 0.4V during output diod...
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8.6. System Efficiency System efficiency is 87.02% ~ 89.6% in 90 ~ 265VAC input voltage range. The results were measured after 30 minutes since startup by using LED load. Efficiency Input Voltage Figu...
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8.7. Power Factor & Total Harmonic Distortion FL7732 shows excellent THD performance. THD is much less than 30% of the specification. Power factor is very high with enough margin from 0.9. The res...
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8.8. Operating Temperature Temperature of the all components on this board is less than 67ºC. The results were measured 60 minutes after startup. Bottom Top Rectifier: 66.6 ºC MOSFET: FL7732: 44.8 ºC ...
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8.9. Electromagnetic Interference (EMI) All measurements were conducted in observance of EN55022 criteria. The results were measured 30 minutes after startup. Figure 24. EMI Results – 10-LED (35V/500m...
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9. Revision History Rev. Date Description 1.0.0 July 2011 Initial Release WARNING AND DISCLAIMER Replace components on the Evaluation Board only with those parts shown on the parts list (or Bill of Ma...
Manual Details
| Brand | Fairchild |
|---|---|
| Pages | 21 |
| File Size | 2.23 MB |
| Published | July 10, 2026 |
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Frequently Asked Questions
What is the input voltage range for this system?
The proposed solution supports an input voltage range of 90V – 265V.
Does the FL7732 IC offer current regulation independently of output voltage?
Yes, precise constant-current control regulates accurate output current regardless of changes in input or output voltage.
What protections does the FL7732 provide?
The FL7732 offers open-LED, short-LED, and over-temperature protections.
Why is the design considered more cost-effective?
The single-stage flyback topology reduces external components, such as input bulk capacitors and feedback circuitry.