User Guide for FEBFL7701_L30U003A 2.4 W LED Ballast Using FL7701 Featured Fairchild Product: FL7701 Direct questions or comments about this evaluation board to: "Worldwide Direct Support" Fairchild Semiconductor.com (c) 2012 Fairchild Semiconductor Corporation 1 FEBFL7701_L30U003A * Rev.1.0.3 Table of Contents 1. Introduction ............................................................................................................................... 3 1.1. General Description.......................................................................................................... 3 1.2. Key Features ..................................................................................................................... 3 1.3. Internal Block Diagram .................................................................................................... 4 2. General Specifications for Evaluation Board ........................................................................... 5 3. Photographs of the Evaluation Board ....................................................................................... 6 4. Printed Circuit Board ................................................................................................................ 7 5. Schematic .................................................................................................................................. 8 6. Bill of Materials ........................................................................................................................ 8 7. Performance of Evaluation Board ............................................................................................. 9 7.1. Typical Waveforms: Startup .......................................................................................... 10 7.2. Operating Frequency & Minimum Duty ........................................................................ 11 7.3. Typical Waveforms: Steady State .................................................................................. 12 7.4. Typical Waveforms: Abnormal Mode (LED Open) ...................................................... 15 7.5. Typical Waveforms: Abnormal Mode (Inductor Short Condition) ............................... 16 7.6. Power Factor (PF) at Rated Load Condition .................................................................. 17 7.7. Total Harmonic Discharge (THD) Performance ............................................................ 18 7.8. System Efficiency .......................................................................................................... 19 7.9. Thermal Performance ..................................................................................................... 20 7.10. Electromagnetic Interference (EMI) Results .............................................................. 22 8. Revision History ..................................................................................................................... 24 (c) 2012 Fairchild Semiconductor Corporation 2 FEBFL7701_L30U003A * Rev. 1.0.3 This FEBFL7701_L30U003A Evaluation Board can be identified by the silkscreen marking FL7701 Board on the top side of the PCB. This user guide supports the evaluation board for the FL7701, FEBFL7701_L30U003A. It should be used in conjunction with the FL7701 datasheet as well as Fairchild's application notes and technical support team. Please visit Fairchild's website at www.fairchildsemi.com or the evaluation board page http://www.fairchildsemi.com/products/evaluationboards/. 1. Introduction This document describes the proposed solution for a universal-input 2.4W LED ballast using the FL7701. The input voltage range is 90 VRMS - 265 VRMS and there is one DC output with a constant current of 85 mA at 28 VMAX. This document contains general description of FL7701, the power supply specification, schematic, bill of materials, and the typical operating characteristics. 1.1. General Description The FL7701 LED lamp driver is a simple IC with PFC function. The special "adopted digital" technique automatically detects input voltage condition and sends an internal reference signal, resulting in high power factor. When an AC input voltage is applied to the IC, the PFC function is automatically enabled. Otherwise, when a DC input is applied to the IC, the PFC function is automatically disabled. The FL7701 does not require a bulk capacitor (electrolytic capacitor) for supply rail stability, which can significantly affect LED reliability. 1.2. Key Features Digitally Implemented Active PFC Function Built-in Self-Biasing HV Startup Circuit Application Input Range: 80 VAC ~ 308 VAC AOCP Function with Auto-Restart Mode Built-in Over-Temperature Protection Cycle-by-Cycle Current Limit Current-Sense Pin Open Protection Low Operating Current: 0.85 mA (Typical) Under-Voltage Lockout with 5 V Hysteresis Programmable Oscillator Frequency Programmable LED Current Analog Dimming Function Fixed Soft-Start Function Precise Internal Reference: 3% (c) 2012 Fairchild Semiconductor Corporation 3 FEBFL7701_L30U003A * Rev. 1.0.3 1.3. Internal Block Diagram Figure 1. Internal Block Diagram Pin Descriptions Pin Symbol 1 CS 2 OUT Output. Connects to the MOSFET gate. 3 VCC Supply Voltage. Supply pin for stable IC operation; ZCD signal detection used for accurate PFC function. 4 RT Resistor. Programmable operating frequency using an external resistor connected to this PIN and the IC has fixed frequency when this pin is left open or floating. 5 ADIM Analog Dimming. Connects to the internal current source and can change the output current using an external resistor. If ADIM is not used, connect a 0.1 F bypass capacitor between ADIM and GND. 6 GND GROUND. Ground for the IC. 7 NC No Connection 8 HV High Voltage. Connect to the high-voltage line and supply current to the IC (c) 2012 Fairchild Semiconductor Corporation Description Current Sense. Limits output current, depending on the sensing resistor voltage. The CS pin is also used to set the LED current regulation. 4 FEBFL7701_L30U003A * Rev. 1.0.3 2. General Specifications for Evaluation Board All data for this table was measured at an ambient temperature of 25C Table 1. Summary of Features and Performance Description Symbol VIN,min 90 V Input Voltage Range VIN,nom 220 V VIN,max 265 V AC Input Frequency Output Voltage/Current Output Power Value fIN,min 47 Hz fIN,max 64 Hz VOUT 28 V Note 1 IOUT 85 mA Output Power 2.41 W Note 2 > 75% At full load Efficiency Temperature Comments TFL7701 < 71.5C TMOSFET < 59.5C TINDUCTOR < 57.7C At full load (all at open frame, room temperature / still air) PCB Size 20 mm (width) x 32 mm (length) x 13 mm (height) Initial Application LED bulb Notes: 1. The output current has ILEDPK ripple. To reduce ripple current, use a large electrolytic capacitor in parallel with the LED. Ensure the capacitor voltage rating is high enough to withstand an open-LED condition or use a Zener diode for protection. 2. The output power is not equal to the apparent power due to the slight phase shift between the output voltage and current. (c) 2012 Fairchild Semiconductor Corporation 5 FEBFL7701_L30U003A * Rev. 1.0.3 3. Photographs of the Evaluation Board Figure 2. Photograph Top View (20 mm x 32 mm x 13 mm) Figure 3. Photograph Bottom View (20 mm x 32 mm x 13 mm) Figure 4. Photograph Side View (20 mm x 32 mm x 13 mm) (c) 2012 Fairchild Semiconductor Corporation 6 FEBFL7701_L30U003A * Rev. 1.0.3 4. Printed Circuit Board Figure 5. PCB, Top Side Figure 6. PCB, Bottom Side (c) 2012 Fairchild Semiconductor Corporation 7 FEBFL7701_L30U003A * Rev. 1.0.3 5. Schematic Figure 7. Schematic of Evaluation 6. Bill of Materials Item Part No. Reference Part Number Qty. Description Manufacturer 1 U1 FL7701 1 Main Controller Fairchild Semiconductor 2 BD MB6S 1 0.5 A / 600 V Bridge Diode Fairchild Semiconductor 3 C1 MPE 630V223K 1 22 nF / 630 VAC 10%, Polypropylene Sungho 4 C2 MPE 630V333K 1 33 nF / 630 VAC 10%, Polypropylene Sungho 5 C3 C0805C101K3RACTU 1 100 pF / 25 V SMD Capacitor 2012 Kemet 6 C4 C1206C225K3PACTU 1 2.2 F / 25 V SMD Capacitor 3216 Kemet 7 D1 UF4007 1 1 A / 1 kV Ultra Fast Recovery Fairchild Semiconductor 8 D2 1N4148 1 1 A / 100 V Small Signal Diode Fairchild Semiconductor 9 L1, L2 R06153KT00 2 1.5 mH Radial Inductor R6.5x7.5 Bosung 10 L3 R06402KT00 1 4 mH Radial Inductor R6.5x7.5 Bosung 11 R1 RC1206JR-07680RL 1 680 SMD Resistor 3216 Yageo 12 R2 RC1206JR-0710KL 1 10k SMD Resistor 3216 Yageo 13 R3 RC0805JR-0724KL 1 24k SMD Resistor 2012 Yageo 14 R4 RC0805JR-07510RL 1 510 SMD Resistor 2012 Yageo 15 R5 RC1206JR-073RL 1 3 SMD Resistor 3216 Yageo (c) 2012 Fairchild Semiconductor Corporation 8 FEBFL7701_L30U003A * Rev. 1.0.3 7. Performance of Evaluation Board Table 2. Test Condition & Equipments Test Temperature TA = 25C Test Equipments AC Source: PCR500L by Kikusui Power Meter: PZ4000 by Yokogawa Oscilloscope: Waverunner 64Xi by Lecroy EMI Test Receiver: ESCS30 by ROHDE & SCHWARZ Two-Line V-Network: ENV216 by ROHDE & SCHWARZ Thermometer: CAM SC640 by FLIR SYSTEMS LED: EHP-AX08EL/GT01H-P03 (3W) by Everlight (c) 2012 Fairchild Semiconductor Corporation 9 FEBFL7701_L30U003A * Rev. 1.0.3 7.1. Typical Waveforms: Startup Figure 8 through Figure 11 show the typical startup performance at different input voltage conditions. When AC input voltage is applied to the system, the FL7701 automatically operates in AC Mode after finishing an internally fixed, seven-cycle, softstart period. Figure 10 and Figure 11 show the soft-start characteristics when a DC input voltage is applied. CH1: VCC, CH2: VDRAIN, CH3: VLED, CH4: ILED CH1: VCC, CH2: VDRAIN, CH3: VLED, CH4: ILED Figure 8. Soft-Start Characteristics, AC Mode, 90 VAC Figure 9. Soft-Start Characteristics, AC Mode, 265 VAC CH1: VCC, CH2: VDRAIN, CH3: VLED, CH4: ILED CH1: VCC, CH2: VDRAIN, CH3: VLED, CH4: ILED Figure 10. Soft-Start Characteristics, DC Mode, 100 VDC Figure 11. Soft-Start Characteristics, DC Mode, 200 VDC (c) 2012 Fairchild Semiconductor Corporation 10 FEBFL7701_L30U003A * Rev. 1.0.3 7.2. Operating Frequency & Minimum Duty The programmable switching frequency is between 20 kHz ~ 250 kHz, determined by selecting the RT resistor value. If no RT resistor is used (RT pin OPEN), the FL7701 default switching frequency is set to 45 kHz. The maximum duty ratio is fixed below 50% and has a fixed minimum typical on-time of 400 ns. There are two crucial points to design properly. The first is consideration of the minimum duty ratio at minimum input voltage because the FL7701 is limited to 50% duty ratio. The second consideration is minimum on-time at maximum input voltage condition. The FL7701 cannot control output power when the operating conditions are such that the required on-time is less than the 400 ns minimum on-time. Minimum on time: 1.12s Switching frequency: 69.91kHz CH1: VCC, CH2: VDRAIN, CH3: VLED, CH4: ILED Figure 12. (c) 2012 Fairchild Semiconductor Corporation Operating Frequency & Minimum Duty 11 FEBFL7701_L30U003A * Rev. 1.0.3 7.3. Typical Waveforms: Steady State Figure 13 through Figure 22 show the normal operation waveform by input voltage & input frequency. The output voltage and current maintains a certain output level with 120 Hz ripple, as shown in the test results in Table 3. CH1: VCC, CH2: VDRAIN, CH3: VLED, CH4: ILED CH1: VCC, CH2: VDRAIN, CH3: VLED, CH4: ILED Figure 13. Input Voltage: 90 VAC, Input Frequency: 47 Hz Figure 14. Input Voltage: 90 VAC, Input Frequency: 64 Hz H1: VCC, CH2: VDRAIN, CH3: VLED, CH4: ILED H1: VCC, CH2: VDRAIN, CH3: VLED, CH4: ILED Figure 15. Input Voltage: 110 VAC, Input Frequency: 47 Hz Figure 16. Input Voltage: 110 VAC, Input Frequency: 64 Hz (c) 2012 Fairchild Semiconductor Corporation 12 FEBFL7701_L30U003A * Rev. 1.0.3 Typical Operating Waveforms: Output Characteristics CH1: VCC, CH2: VDRAIN, CH3: VLED, CH4: ILED CH1: VCC, CH2: VDRAIN, CH3: VLED, CH4: ILED Figure 17. Input Voltage: 180 VAC, Input Frequency: 47 Hz Figure 18. Input Voltage: 180 VAC, Input Frequency: 64 Hz CH1: VCC, CH2: VDRAIN, CH3: VLED, CH4: ILED CH1: VCC, CH2: VDRAIN, CH3: VLED, CH4: ILED Figure 19. Input Voltage: 220 VAC, Input Frequency: 47 Hz Figure 20. Input Voltage: 220 VAC, Input Frequency: 64 Hz H1: VCC, CH2: VDRAIN, CH3: VLED, CH4: ILED H1: VCC, CH2: VDRAIN, CH3: VLED, CH4: ILED Figure 21. Input Voltage: 265 VAC, Input Frequency: 47 Hz Figure 22. Input Voltage: 265 VAC, Input Frequency: 64 Hz (c) 2012 Fairchild Semiconductor Corporation 13 FEBFL7701_L30U003A * Rev. 1.0.3 Table 3. Output Characteristics by Input Voltage & Frequency 47 Hz 64 Hz VLED(RMS) ILED(RMS) VLED(RMS) ILED(RMS) 90 VAC 27.91 V 84.45 mA 27.90 V 84.58 mA 110 VAC 27.99 V 84.41 mA 28.02 V 84.49 mA 180 VAC 28.13 V 84.94 mA 28.10 V 84.86 mA 220 VAC 28.12 V 85.66 mA 28.14 V 85.77 mA 265 VAC 28.17 V 87.05 mA 28.13 V 87.05 mA (c) 2012 Fairchild Semiconductor Corporation 14 FEBFL7701_L30U003A * Rev. 1.0.3 7.4. Typical Waveforms: Abnormal Mode (LED Open) Figure 23 and Figure 24 show the open-load condition test method and result. When the LED disconnects from the system, the IC cannot operate because the HV pin is disconnected. Figure 23. Open-Load Condition Test CH1: VCC, CH2: VDRAIN, CH3: VLED, CH4: ILED Figure 24. (c) 2012 Fairchild Semiconductor Corporation Test Results of Open-Load Condition 15 FEBFL7701_L30U003A * Rev. 1.0.3 7.5. Typical Waveforms: Abnormal Mode (Inductor Short Condition) Figure 25 and Figure 26 show the test method and result of an inductor short condition. The FL7701 uses an abnormal over-current protection (AOCP) function, limiting the current on RCS in the event of an inductor short condition. Figure 25. Inductor Short Condition When CS pin voltage reached 2.5V, AOCP operates after internal delay time 70ns (typical) CH1: VCS, CH2: VDRAIN, CH3: VLED, CH4: ILED Figure 26. (c) 2012 Fairchild Semiconductor Corporation Test Results of Inductor Short Condition 16 FEBFL7701_L30U003A * Rev. 1.0.3 7.6. Power Factor (PF) at Rated Load Condition Figure 27 shows the system PF performance for the entire input voltage range (90 V to 265 V) at different input frequency conditions (47 Hz, 64 Hz). The PF slightly changes according to the input frequency but can achieve over 86% at 265 VAC condition. 100 95 90 85 80 [%] 75 PF_47Hz 70 PF_64Hz 65 60 55 50 90 110 180 220 264 [VAC] Figure 27. Power Factor Table 4. Power Factor Test Results Input Voltage 90 VAC 110 VAC 180 VAC 220 VAC 265 VAC (c) 2012 Fairchild Semiconductor Corporation Power Factor 47 Hz 96.31 64 Hz 97.34 47 Hz 96.72 64 Hz 96.89 47 Hz 94.41 64 Hz 93.74 47 Hz 92.49 64 Hz 91.09 47 Hz 89.71 64 Hz 86.56 17 FEBFL7701_L30U003A * Rev. 1.0.3 7.7. Total Harmonic Discharge (THD) Performance Figure 28 shows the THD performance at different input frequencies. Test results are quite similar, except the 90 VAC condition, but meets international regulations (under 30%). 30 25 [%] 20 THD_47Hz 15 THD_64Hz 10 5 0 90 110 Figure 28. Table 5. 180 220 264 [VAC] Total Harmonic Distortion Performance Total Harmonic Distortion Test Results Input Voltage 90 VAC 110 VAC 180 VAC 220 VAC 265 VAC (c) 2012 Fairchild Semiconductor Corporation 18 Frequency THD (%) 47 Hz 20.99 64 Hz 21.82 47 Hz 22.26 64 Hz 22.46 47 Hz 24.96 64 Hz 25.31 47 Hz 25.50 64 Hz 25.84 47 Hz 25.75 64 Hz 26.72 FEBFL7701_L30U003A * Rev. 1.0.3 7.8. System Efficiency Figure 29 shows system efficiency results for different AC input voltage frequency conditions. As shown, the input frequency has negligible effect on system efficiency. 100 95 90 85 80 [%] Efficiency_47Hz 75 Efficiency_64Hz 70 65 60 55 50 90 110 180 Figure 29. Table 6. 220 264 [VAC] System Efficiency Efficiency Test Results Input Voltage 90 VAC 110 VAC 180 VAC 220 VAC 265 VAC (c) 2012 Fairchild Semiconductor Corporation 19 Frequency Efficiency (%) 47 Hz 83.56 64 Hz 83.83 47 Hz 83.36 64 Hz 83.46 47 Hz 80.04 64 Hz 80.06 47 Hz 77.68 64 Hz 77.69 47 Hz 75.11 64 Hz 75.22 FEBFL7701_L30U003A * Rev. 1.0.3 7.9. Thermal Performance Figure 30 through Figure 37 show the steady-state thermal results with different input voltage conditions. Inductor L3 has the highest temperature on the top side of the PCB due to copper resistance. The FL7701 has the highest temperature on the bottom side of the PCB due to power loss associated with the high-voltage device. The IC temperature is 66.5C for the 220 VAC input condition. Figure 30. Thermal Test Result, Bottom-Side Temperature at 90 VAC Condition (IC) Figure 31. Thermal Test Result, Top-Side Temperature at 90 VAC Condition (Inductor) Figure 32. Thermal Test Result, Bottom-Side Temperature at 110 VAC Condition (IC) Figure 33. Thermal Test Result, Top-Side Temperature at 110 VAC Condition (Inductor) (c) 2012 Fairchild Semiconductor Corporation 20 FEBFL7701_L30U003A * Rev. 1.0.3 Figure 34. Thermal Test Result, Bottom-Side Temperature at 220 VAC Condition (IC) Figure 35. Thermal Test Result, Top-Side Temperature at 220 VAC Condition (Inductor) Figure 36. Thermal Test Result, Bottom-Side Temperature at 264 VAC Condition (IC) Figure 37. Thermal Test Result, Top-Side Temperature at 264 VAC Condition (Inductor) Table 7. Temperature Performance by Input Voltage Input Voltage TIC TMOSFET TINDUCTOR 90 VAC 47.6C 46.2C 47.8C 110 VAC 51.4C 46.9C 47.8C 220 VAC 66.5C 55.0C 54.6C 265 VAC 71.5C 59.5C 57.7C (c) 2012 Fairchild Semiconductor Corporation 21 FEBFL7701_L30U003A * Rev. 1.0.3 7.10. Electromagnetic Interference (EMI) Results EMI test measurements were conducted in observance of CISPR22 criteria, which has tighter stricter limits than CISPR15 for lighting applications. Figure 38. Figure 39. (c) 2012 Fairchild Semiconductor Corporation EMI Test Results, Conducted Emission-Line at 11 0VAC Input Condition, Full Load (10-LED Series) EMI Test Results, Conducted Emission-Neutral at 110 VAC Input Condition, Full Load (10-LED Series) 22 FEBFL7701_L30U003A * Rev. 1.0.3 Figure 40. EMI Test Results, Conducted Emission-Neutral at 220 VAC Input Condition, Full Load (10-LED Series) Figure 41. EMI Test Results, Conducted Emission-Neutral at 220 VAC Input Condition, Full Load (10-LED Series) (c) 2012 Fairchild Semiconductor Corporation 23 FEBFL7701_L30U003A * Rev. 1.0.3 8. Revision History Rev. Date Description 1.0.0 Nov. 2011. First issue 1.0.1 Dec. 2011. Update IC temperature 1.0.2 Feb. 2012. Modified, edited, formatted document. Changed User Guide number from FEB_L030 to FEBFL7701_L30U003A 1.0.3 Aug. 2012 Formatted document WARNING AND DISCLAIMER Replace components on the Evaluation Board only with those parts shown on the parts list (or Bill of Materials) in the Users' Guide. Contact an authorized Fairchild representative with any questions. This board is intended to be used by certified professionals, in a lab environment, following proper safety procedures. Use at your own risk. 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