Fairchild FEB-L020-1 service manual

User Guide for

FEB-L020-1

Dimmable LED Bulb at Low Line

Featured Fairchild Product:

FL7730

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 ........................................................................................................ 3

1.2. Features .......................................................................................................................... 3

1.3. Internal Block Diagram .................................................................................................. 4

2. General Specifications .............................................................................................................. 5

3. Photographs............................................................................................................................... 6

4. Printed Circuit Board ................................................................................................................ 7

5. Schematic .................................................................................................................................. 8

6. Bill of Materials ........................................................................................................................ 9

7. Transformer and Winding Specifications ............................................................................... 11

8. Performance of Evaluation Board ........................................................................................... 12

8.1. Startup .......................................................................................................................... 12

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

8.3. Constant Current Regulation ........................................................................................ 13

8.4. Open/Short-LED Protections ....................................................................................... 14

8.5. Dimming Operation ...................................................................................................... 15

8.6. System Efficiency ........................................................................................................ 18

8.7. Power Factor and Total Harmonic Distortion .............................................................. 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 FL7730. It should be used in conjunction with the FL7730 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 the proposed solution for low-line voltage LED ballast using the FL7730 Primary-Side Regulator (PSR) single-stage controller. The input voltage range is 90V 22V specification, schematic, bill of materials, and the typical operating characteristics.

1.1. General Description

The FL7730 is an active Power Factor Correction (PFC) controller using single-stage flyback topology. Dimming control with no flicker is implemented by an analog sensing method. Primary-side regulation and single-stage topology reduce external components such as input bulk capacitor and feedback circuitry and minimize cost. To improve good power factor and Total Harmonic Distortion (THD), constant on-time control is utilized with 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 DCM operation with higher efficiency. FL7730 provides protections such as open-LED, short-LED, and over-temperature protection.

– 140V

RMS

. This document contains general description of FL7730, the power supply

MAX

.

and there is one DC output with a constant current of 380mA at

RMS

1.2. Features

 Compatible with Traditional TRIAC Control  Cost-Effective Solution without Input Bulk Capacitor and Feedback Circuitry  Power Factor Correction (PFC)  Accurate Constant-Current (CC) Control  Line Voltage Compensation for CC Control  Linear Frequency Control for Better Efficiency and Simpler Design  Open-LED Protection  Short-LED Protection  Cycle-by-Cycle Current Limiting  Over-Temperature Protection with Auto Restart  Low Startup Current: 20μA  Low Operating Current: 5mA  V

Under-Voltage Lockout (UVLO)

DD

 Gate Output Maximum Voltage Clamped at 18V  SOP-8 Package Available

1.3. Internal Block Diagram

Figure 1. Internal Block Diagram

2. General Specifications

All data in Table 1 was measured at an ambient temperature of 25°C.

Table 1. Summary of Features and Performance for LED Lighting Bulb

Description Symbol Value Comments

V

Input Voltage

Input Frequency fIN 50-60Hz Line Frequency

Output Voltage Current

Efficiency

PF / THD

Temperature

VIN,

V

IN,NOMINAL

V

OUT,MIN

V

OUT,MAX

V

OUT,NOMINAL

I

OUT,NOMINAL

I

OUT,RIPPLE

CC Deviation

Eff

PF / THD

T

FL7730

T

MOSFET

T

TRANSFORMER

T

DAMPER

T

STR.RESISTOR

90V Minimum Input Voltage

IN,MIN

140V Maximum Input Voltage

MAX

110~120V Nominal Input Voltage

10V Minimum Output Voltage

28V Maximum Output Voltage

22V Nominal Output Voltage

380mA Nominal Output Current

±65mA Output Current Ripple

<±3.9% Line Input Voltage Change:90~140VAC

<±2.1% Output Voltage Change:10~28V

Note: No Dimmer Connected

90VAC

110VAC

120VAC

82.9% Efficiency at 140VAC Line Input Voltage

140VAC

80.7% Efficiency at 90VAC Line Input Voltage

82.2% Efficiency at 110VAC Line Input Voltage

82.5% Efficiency at 120VAC Line Input Voltage

Note: No Dimmer Connected

0.98 / 7.4% PF / THD at 90VAC Line Input Voltage

90VAC

0.96 / 9.5% PF / THD at 110VAC Line Input Voltage

110VAC

0.95 / 10.4% PF / THD at 120VAC Line Input Voltage

120VAC

0.91 / 12.4% PF / THD at 140 VAC Line Input Voltage

140VAC

Note: Open-Frame Condition (TA=25°C)

50ºC FL7730 Temperature

53ºC Primary MOSFET Temperature

47ºC Secondary Diode Temperature

DIODE

52ºC Transformer Temperature

57ºC Active Damper Temperature

56ºC Startup Resistor Temperature

3. Photographs

Figure 2. Top View of Evaluation Board Figure 3. Bottom View of Evaluation Board

Dimensions: 62.5mm (L)  26.8mm (W)  12.0 (H)

Figure 4. Side View in Bulb Case Type 1 Figure 5. Bottom View in Bulb Case Type 1

Bulb Case Type 1 : 32mm (Case Diameter)  40mm (Case Depth)

Figure 6. Side View in Bulb Case Type 2 Figure 7. Bottom View in Bulb Case Type 2

Bulb Case Type 2 : 34mm (Case Diameter)  44mm (Case Depth)

4. Printed Circuit Board

Figure 8. Printed PCB, Top Side

Figure 9. Printed PCB, Bottom Side