FEBFL7733A_L50U008A - Fairchild Semiconductor

User Guide for

FEBFL7733A_L50U008A

Evaluation Board

8.4 W LED Driver at Universal Line

Featured Fairchild Product:

FL7733A

Direct questions or comments

about this evaluation board to:

“Worldwide Direct Support”

Fairchild Semiconductor.com

Table of Contents

1. Introduction ............................................................................................................................... 3

1.1. General Description of FL7733A .................................................................................... 3

1.2. FL7733A Controller Features .......................................................................................... 3

1.3. FL7733A Controller Internal Block Diagram .................................................................. 4

2. Evaluation Board Specifications ............................................................................................... 5

3. Evaluation Board Photographs ................................................................................................. 6

4. Evaluation Board Printed Circuit Board (PCB) ........................................................................ 7

5. Evaluation Board Schematic ..................................................................................................... 8

6. Evaluation Board Bill of Materials (BOM) .............................................................................. 9

7. Transformer Design ................................................................................................................ 10

8. Evaluation Board Performance ............................................................................................... 11

8.1. Startup ............................................................................................................................ 11

8.2. Operation Waveforms .................................................................................................... 12

8.3. Constant-Current Regulation ......................................................................................... 14

8.4. Short / Open-LED Protections ....................................................................................... 15

8.5. Efficiency ....................................................................................................................... 17

8.6. Power Factor (PF) & Total Harmonic Distortion (THD) .............................................. 18

8.7. Harmonics ...................................................................................................................... 19

8.8. Operating Temperature .................................................................................................. 21

8.9. Electromagnetic Interference (EMI) .............................................................................. 22

9. Revision History ..................................................................................................................... 23

This user guide supports the evaluation kit for the FL7733A. It should be used in

conjunction with the FL7733A datasheet as well as Fairchild’s application notes and

technical support team. Please visit Fairchild’s website at www.fairchildsemi.com.

1. Introduction

This document describes a solution for a universal AC input voltage LED driver using the

FL7733A Primary-Side Regulator (PSR) single-stage controller. The input voltage range

is 90 VRMS ~ 265 VRMS and there is one DC output with a constant current of 350 mA at

24 V. This document contains a general description of the FL7733A, the power supply

solution specification, schematic, bill of materials, and typical operating characteristics.

1.1. General Description of FL7733A

The FL7733A is an active Power Factor Correction (PFC) controller used in a single-

stage flyback topology or buck-boost topology. Primary-side regulation and a single-

stage topology reduce external components, such as the input bulk capacitor and

feedback circuitry, minimizing cost. To improve power factor and Total Harmonic

Distortion (THD), constant on-time control is utilized with an internal error amplifier and

a low bandwidth compensator. Precise constant-current control regulates accurate output

current, independent of input voltage and output voltage. Operating frequency is

proportionally changed by output voltage to guarantee Discontinuous Current Mode

(DCM) operation, resulting in high efficiency and a simple design. The FL7733A

provides open-LED, short-LED, and over-temperature protections.

1.2. Controller Features

High Performance

 Cost-Effective Solution; No Input Bulk Capacitor / Secondary Feedback

Circuitry

 Power Factor Correction

 THD <10% Over Universal Input Line Range

 CC Tolerance:

< ±1% Over Universal Input Line Voltage Variation

< ±1% by 50% ~ 100% Load Voltage Variation

< ±1% by ±20% Magnetizing Inductance Variation

 High-Voltage Startup with VDD Regulation

 Adaptive Feedback Loop Control for No Overshoot at Startup

High Reliability

 LED Short / Open Protection

 Output Diode Short Protection

 Sensing Resistor Short / Open Protection

 VDD Over-Voltage Protection (OVP)

 VDD Under-Voltage Lockout (UVLO)

 Over-Temperature Protection (OTP)

 All Protections are Auto Restart

 Cycle-by-Cycle Current Limit

 Application Voltage Range: 80 VAC ~ 308 VAC

1.3. Controller Internal Block Diagram

Figure 1. Block Diagram

2. Evaluation Board Specifications

Table 1. Specifications for LED Lighting Load

Description Symbol Value Comments

Input Voltage

VIN.MIN 90 VAC Minimum AC Input Voltage

VIN.MAX 265 VAC Maximum AC Input Voltage

VIN.NOMINAL 120 V / 230 V Nominal AC Input Voltage

Frequency fIN 60 Hz / 50 Hz Line Frequency

Output

Voltage

VOUT.MIN 13 V Minimum Output Voltage

VOUT.MAX 28 V Maximum Output Voltage

VOUT.NOMINAL 24 V Nominal Output Voltage

Current

IOUT.NOMINAL 350 mA Nominal Output Current

CC Deviation

< ±0.29% Line Input Voltage Change: 90~265 VAC

< ±0.72% Output Voltage Change: 13~28 V

Efficiency

Eff90VAC 86.41% Efficiency at 90 VAC Input Voltage

Eff120VAC 87.88% Efficiency at 120 VAC Input Voltage

Eff140VAC 88.25% Efficiency at 140 VAC Input Voltage

Eff180VAC 88.68% Efficiency at 180 VAC Input Voltage

Eff230VAC 88.95% Efficiency at 230 VAC Input Voltage

Eff265VAC 88.96% Efficiency at 265 VAC Input Voltage

PF/THD

PF / THD90VAC 0.996 / 3.85% PF/THD at 90 VAC Input Voltage

PF / THD120VAC 0.992 / 3.61% PF/THD at 120 VAC Input Voltage

PF / THD140VAC 0.988 / 4.16% PF/THD at 140 VAC Input Voltage

PF / THD180VAC 0.975 / 4.90% PF/THD at 180 VAC Input Voltage

PF / THD230VAC 0.945 / 6.01% PF/THD at 230 VAC Input Voltage

PF / THD265VAC 0.914 / 7.06% PF/THD at 265 VAC Input Voltage

Temperature

FL7733A TFL7733A 52.9°C Open-Frame Condition

(TA = 25ºC) FL7733A Temperature

Primary

MOSFET TMOSFET 61.2°C Primary MOSFET Temperature

Secondary

Diode TDIODE 52.8°C Secondary Diode Temperature

Transformer TTRANSFORMER 56.0°C Transformer Temperature

All data of the evaluation board measured with the board enclosed in a case and external

temperature around 25°C.

3. Evaluation Board Photographs

Dimensions: 64 mm (L) x 26 mm (W) x 26 mm (H)

Figure 2. Top View

Figure 3. Bottom View

4. Evaluation Board Printed Circuit Board (PCB)

Figure 4. Top Pattern (in mm)

Figure 5. Bottom Pattern

5. Evaluation Board Schematic

F1

1A/250V

NPNS

NA

C2

/10µF

R4

/180kΩ

R5

/27kΩ

R6

/10Ω

Rcs2

2.4Ω

D2

/1N4003

C4/5pF

CF2

/47nF

C1

400V/

68nF

L

N

LF1/

10mH

Q1/

FQU5N60C

1

COMI

HV

NC

VDD

CSGND

Gate

VS

7

8

5

62

3

4

U1

FL7733

RS1

/100kΩ

DS1

/RS1M

CS1

/10nF Co1

/470µF

Do1

/ES3D

C3

/10nF

MOV1

/470

BD1

/MB6S

C5/2.2µF

Cy1

2.2nF

CF1

/47nF Ro1

/20kΩ

R2/30kΩ

R1/30kΩ

Rcs1

2.0Ω

RS2

/100kΩ

T1

+

R7

/330Ω

Figure 6. Schematic

6. Evaluation Board Bill of Materials (BOM)

Item

No.

Part

Reference Part Number Qty. Description Manufacturer

1 BD1 MB8S 1 Bridge Diode Fairchild

Semiconductor

2 CF1 MPX AC275V 473 K 2 47 nF / AC275V, X-Capacitor Carli

3 CS1 C1206C103KDRACTU 1 10 nF / 1 kV, SMD Capacitor 1206 Kemet

4 CY1 SCFz2E222M10BW 1 2.2 nF / 250 V, Y-Capacitor Samwha

5 Co1 NXH 470 µF 35 V 1 470 µF / 35 V, Electrolytic Capacitor Samyoung

6 C1 MPE400V683K 1 68 nF / 400 V, MPE Film Capacitor Sungho

7 C2 KMG10 μF 35 V 1 10 µF / 35 V, Electrolytic Capacitor Samyoung

8 C3 C0805C104K5RACTU 1 100 nF / 50 V, SMD Capacitor 2012 Kemet

9 C4 C0805C519C3GACTU 1 5 pF / 25 V, SMD Capacitor 2012 Kemet

10 C5 C0805C225J3RACTU 1 2.2 µF / 25 V, SMD Capacitor 2012 Kemet

11 DS1 RS1M 1 1000 V / 1 A, Ultra-Fast Recovery Diode Fairchild

Semiconductor

12 Do1 ES3D 1 200 V / 3 A, Fast Rectifier Fairchild

Semiconductor

13 D2 1N4003 1 200 V / 1 A, General-Purpose Rectifier Fairchild

Semiconductor

14 F1 SS-5-1A 1 250 V / 1 A, Fuse Bussmann

15 LF1 R10302KT00 1 10 mH, Inductor, 8Ø Bosung

16 MOV1 SVC471D-07A 1 Metal Oxide Varistor Samwha

17 Q1 FQU5N60C 1 600 V / 4 A, N-Channel MOSFET Fairchild

Semiconductor

18 R6 RC0805JR-0710RL 1 10 Ω, SMD Resistor 0805 Yageo

19 RS1, RS2 RC1206JR-07100KL 2 100 kΩ, SMD Resistor 1206 Yageo

20 Rcs1 RC1206JR-072RL 1 2 Ω, SMD Resistor 1206 Yageo

21 Rcs2 RC1206JR-072R4L 1 2.4 Ω, SMD Resistor 1206 Yageo

22 R7 RC0805JR-07330RL 1 330 Ω, SMD Resistor 0805 Yageo

23 Ro1 RC1206JR-0720KL 1 20 kΩ, SMD Resistor 1206 Yageo

24 R4 RC0805JR-07180KL 1 180 kΩ, SMD Resistor 0805 Yageo

25 R1, R2 RC1206JR-0730KL 2 30 kΩ, SMD Resistor 1206 Yageo

26 R5 RC0805JR-0727KL 1 27 kΩ, SMD Resistor 0805 Yageo

27 T1 RM6 Core 1 6-Pin, Transformer TDK

28 U1 FL7733A 1 Main PSR Controller Fairchild

Semiconductor

7. Transformer Design

Figure 7. Transformer Bobbin Structure and Pin Configuration

Figure 8. Transformer Winding Structure

Table 2. Winding Specifications

No. Winding Pin (S → F) Wire Turns Winding Method

1 NP1 6 1 0.20φ 54 Ts Solenoid Winding

2 Insulation: Polyester Tape t = 0.025 mm, 3-Layer

3 NS NS+  NS- 0.25φ (TIW) 25 Ts Solenoid Winding

4 Insulation: Polyester Tape t = 0.025 mm, 3-Layer

5 NP2 1  2 0.20φ 27 Ts Solenoid Winding

6 Insulation: Polyester Tape t = 0.025 mm, 3-Layer

7 NA 5  3 0.20φ 17 Ts Solenoid Winding

8 Insulation: Polyester Tape t = 0.025 mm, 3-Layer

Table 3. Electrical Characteristics

Pins Specifications Remark

Inductance 6 – 2 1.0 mH ±10% 60 kHz, 1 V

Leakage 6 – 2 10 µH 60 kHz, 1 V, Short All Output Pins

8. Evaluation Board Performance

Table 4. Test Condition & Equipment List

Ambient Temperature TA = 25°C

Test Equipment

AC Power Source: PCR500L by Kikusui

Power Analyzer: PZ4000000 by Yokogawa

Electronic Load: PLZ303WH by KIKUSUI

Multi Meter: 2002 by KEITHLEY, 45 by FLUKE

Oscilloscope: 104Xi by LeCroy

Thermometer: Thermal CAM SC640 by FLIR SYSTEMS

LED: EHP-AX08EL/GT01H-P03 (3 W) by Everlight

8.1. Startup

Figure 9 and Figure 10 show the overall startup performance at rated output load. The

output load current starts flowing after about 0.2 s and 0.1 s for input voltage 90 VAC and

265 VAC condition when the AC input power switch turns on. CH1: VDD (10 V / div),

CH2: VIN (100 V / div), CH3: VLED (20 V / div), CH4: ILED (200 mA / div), Time Scale:

(100 ms / div), Load: 7 series-LEDs.

Figure 9. VIN = 90 VAC / 60 Hz Figure 10. VIN = 120 VAC / 60 Hz

0.2 s 0.1 s

8.2. Operation Waveforms

Figure 11 to Figure 14 show AC input and output waveforms at rated output load.

CH1: IIN (200 mA / div), CH2: VIN (100 V / div), CH3: VLED (20 V / div), CH4: ILED

(200 mA / div), Time Scale: (5 ms / div), Load: 7 series LEDs.

Figure 11. VIN = 90 VAC / 60 Hz Figure 12. VIN = 120 VAC / 60 Hz

Figure 13.

V

IN = 230

V

AC

/

50 Hz Figure 14.

V

IN = 265

V

AC

/

50 Hz

Figure 15 to Figure 18 show key waveforms of single-stage flyback converter operation

for line voltage at rated output load. CH1: VCS (500 mA / div), CH2: VDS (200 V / div),

CH3: VSEC-Diode (100 V / div), CH4: ISEC-Diode (2.0 A / div), Load: 7 series-LEDs.

Figure 15. VIN = 90 VAC / 60 Hz, [2.0 ms / div] Figure 16. VIN = 90 VAC / 60 Hz, [5.0 µs / div]

Figure 17. VIN = 265 VAC / 60 Hz, [2.0 ms / div] Figure 18. VIN = 265 VAC / 60 Hz, [5.0 µs / div]

8.3. Constant-Current Regulation

The output current deviation for wide output voltage ranges, from 13 V to 28 V, is less

than ±0.8% at each line voltage. Line regulation at the rated output voltage (24 V) is less

than ±0.3%. The results were measured with E-load [CR Mode].

Figure 19. Constant-Current Regulation

Table 5. Constant-Current Regulation by Output Voltage Change (13 ~ 28 V)

Input Voltage Min. Current [mA] Max. Current [mA] Tolerance

90 VAC [60 Hz] 346 350 ±0.57%

120 VAC [60 Hz] 346 351 ±0.72%

140 VAC [60 Hz] 346 351 ±0.72%

180 VAC [50 Hz] 347 352 ±0.72%

230 VAC [50 Hz] 347 352 ±0.72%

265 VAC [50 Hz] 348 353 ±0.71%

Table 6. Constant-Current Regulation by Line Voltage Change (90 ~ 265 VAC)

Output

Voltage

90 VAC

[60 Hz]

120 VAC

[60 Hz]

140 VAC

[60 Hz]

180 VAC

[50 Hz]

230 VAC

[50 Hz]

265 VAC

[50 Hz] Tolerance

26 V 347 mA 348 mA 348 mA 348 mA 349 mA 349 mA ±0.29%

24 V 348 mA 349 mA 349 mA 350 mA 350 mA 350 mA ±0.29%

22 V 349 mA 350 mA 349 mA 350 mA 351 mA 351 mA ±0.29%

8.4. Short- / Open-LED Protections

Figure 20 to Figure 23 show waveforms for protections operated when the LED is

shorted and recovered. Once the LED short occurs, SCP is triggered and VDD starts

hiccup mode with JFET regulation times [250 ms]. This lasts until the fault condition is

eliminated. Systems can restart automatically when returned to normal condition. CH1:

VGATE (10 V / div), CH2: VIN (100 V / div), CH3: VDD (5 V / div), IOUT (200 mA / div),

Time Scale: (200 ms / div).

Figure 20. VIN = 90 VAC / 60 Hz, [LED Short] Figure 21.

V

IN =90

V

AC

/

60 Hz, [LED Restore]

Figure 22. VIN = 265 VAC / 50 Hz, [LED Short] Figure 23.

V

IN = 265

V

AC

/

50 Hz, [LED Restore]

LED Short

A

uto Restart

JFET Turn Off

JFET Turn On

LED Short

A

uto Restart

Figure 24 to Figure 27 show waveforms for protections operated when the LED is opened

and recovered. Once the LED has opened, VS OVP or VDD OVP are triggered and VDD

starts “Hiccup” Mode with JFET regulation times [250 ms]. This lasts until the fault

condition is eliminated. Systems can restart automatically when returned to normal

condition. VGATE (10 V / div), CH2: VIN (100 V / div), CH3: VDD (10 V / div), VOUT (10 V

/ div), Time Scale: (200 ms / div).

Figure 24.

V

IN = 90

V

AC

/

60 Hz, [LED Short] Figure 25.

V

IN = 90

V

AC

/

60 Hz, [LED Restore]

Figure 26.

V

IN = 265

V

AC

/

50 Hz, [LED Short] Figure 27.

V

IN = 265

V

AC

/

50 Hz, [LED Restore]

If the LED load is re-connected after an open-LED condition, the output capacitor is

quickly discharged through the LED load and the inrush current by the discharge could

destroy LED load.

LED Open

A

uto Restart

A

uto Restart

8.5. Efficiency

System efficiency is 86.41% ~ 88.96% over input voltages 90 ~ 265 VAC. The results

were measured using actual, rated LED loads 30 minutes after startup.

Figure 28. System Efficiency

Table 7. System Efficiency

Input Voltage Input Power Output

Current

Output

Voltage

Output

Power Efficiency

90 VAC [60 Hz] 9.52 W 0.351 A 23.43 V 8.23 W 86.41%

120 VAC [60 Hz] 9.39 W 0.352 A 23.45 V 8.25 W 87.88%

140 VAC [60 Hz] 9.38 W 0.352 A 23.49 V 8.28 W 88.25%

180 VAC [50 Hz] 9.33 W 0.354 A 23.40 V 8.27 W 88.68%

230 VAC [50 Hz] 9.35 W 0.355 A 23.42 V 8.32 W 88.95%

265 VAC [50 Hz] 9.38 W 0.356 A 23.46 V 8.34 W 88.96%

8.6. Power Factor (PF) & Total Harmonic Distortion (THD)

The FL7733A evaluation board shows excellent THD performance, much less than 10%.

The results were measured using actual, rated LED loads ten (10) minutes after startup.

Figure 29. Power Factor & Total Harmonic Distortion

Table 8. Power Factor & Total Harmonic Distortion

Input Voltage Output Current Output Voltage Power Factor THD

90 VAC [60 Hz] 0.351 A 23.43 V 0.996 3.85%

120 VAC [60 Hz] 0.352 A 23.45 V 0.992 3.61%

140 VAC [60 Hz] 0.352 A 23.49 V 0.988 4.16%

180 VAC [50 Hz] 0.354 A 23.40 V 0.975 4.90%

230 VAC [50 Hz] 0.355 A 23.42 V 0.945 6.01%

265 VAC [50 Hz] 0.356 A 23.46 V 0.914 7.06%

THD

PF

8.7. Harmonics

Figure 30 to Figure 33 show current harmonics measured using actual, rated LED loads.

Figure 30. VIN = 90 VAC / 60 Hz

Figure 31. VIN = 120 VAC / 60 Hz

Figure 32. VIN = 230 VAC / 50 Hz

Figure 33. VIN = 265 VAC / 50 Hz

8.8. Operating Temperature

Temperatures on all components for this board are less than 62ºC. The results were

measured using actual, rated LED loads 60 minutes after startup.

Figure 34. VIN = 90 VAC / 60 Hz Figure 35.

V

IN = 265

V

AC

/

50 Hz

Figure 36. VIN = 90 VAC / 60 Hz Figure 37.

V

IN = 265

V

AC

/

50 Hz

The IC temperature can be improved by the PCB layout.

Bottom

Top

MOSFET: 61.2 ºC

Rectifier: 52.8 ºC

Trans: 56.0 ºC

FL7733A: 52.9

º

C

Bottom

Rectifier: 52.3 ºC

MOSFET: 59.3 ºC

FL7733A: 53.3

º

C

Trans: 56.9 ºC

Top

8.9. Electromagnetic Interference (EMI)

All measurements were conducted in observance of EN55022 criteria. The results were

measured using actual, rated LED loads 30 minutes after startup.

Figure 38. VIN [110 VAC, LIVE]

Figure 39. VIN [220 VAC, Neutral]

9. Revision History

Rev. Date Description

1.0 Oct. 2014 Initial Release

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.

The Evaluation board (or kit) is for demonstration purposes only and neither the Board nor this User’s Guide constitute a sales contract or create any

kind of warranty, whether express or implied, as to the applications or products involved. Fairchild warrantees that its products meet Fairchild’s

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notice to any products described herein to improve reliability, function, or design. Either the applicable sales contract signed by Fairchild and Buyer or,

if no contract exists, Fairchild’s standard Terms and Conditions on the back of Fairchild invoices, govern the terms of sale of the products described

herein.

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FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS HEREIN TO

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2. A critical component is any component of a life support device or

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FEBFL7733A_L50U008A