Fairchild FEB-L026 service manual

User Guide for

FEB-L026

Evaluation Board

Universal Line Voltage LED Ballast

Featured Fairchild Product:

FL7732

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 FL7732 ....................................................................................... 3

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

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

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

2.1. Evaluation Board ............................................................................................................. 6

2.2. Printed Circuit Board ....................................................................................................... 7

2.3. Schematic of the Evaluation Board .................................................................................. 8

2.4. Bill of Materials ............................................................................................................... 9

2.5. Transformer Design ....................................................................................................... 10

3. Performance of Evaluation Board ......................................................................................... 11

3.1. Startup ............................................................................................................................ 12

3.2. Operation Waveforms .................................................................................................... 13

3.3. Constant-Current Regulation ......................................................................................... 14

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

3.5. Power Factor .................................................................................................................. 16

3.6. PF & THD ...................................................................................................................... 17

3.7. Operating Temperature .................................................................................................. 18

3.8. EMI ................................................................................................................................ 19

4. Revision History .................................................................................................................... 20

This 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. Please visit Fairchild’s website at www.fairchildsemi.com

1. Introduction

This document describes the proposed solution for universal line voltage LED ballast using the FL7732 Primary-Side Regulator (PSR) single-stage controller. The input voltage range is 90V 700mA at 24V supply specification, schematic, bill of materials, and the typical operating characteristics.

1.1. General Description of FL7732

The FL7732 is an active Power Factor Correction (PFC) controller using single-stage flyback topology. Primary-side regulation and single-stage topology reduce external components, such as input bulk capacitor and feedback circuitry, and minimize cost. To improve power factor and 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 DCM operation with high efficiency and simple design. FL7732 provides open-LED, short-LED, and overtemperature protections.

– 265V

RMS

. This document contains general description of FL7732, the power

MAX

and there is one DC output with a constant current of

RMS

.

1.2. Features

 Cost-Effective Solution: No Input Bulk Capacitor or Feedback Circuitry  Power Factor Correction  Accurate Constant-Current (CC) Control, Independent Online Voltage, Output

Voltage, and Magnetizing Inductance Variation

 Linear Frequency Control Improves Efficiency and Simplifies 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

1.3. Internal Block Diagram

Figure 1. Block Diagram of FL7732

2. Specifications for Evaluation Board

Table 1. Specifications for LED Lighting Lamp

Description Symbol Value Comments

V

90V Minimum Input Voltage

IN.MIN

V

Input

Output

Efficiency

PF/THD

Temperature

Voltage

Frequency

Voltage

Current

FL7732

Primary

MOSFET

Secondary

Diode

V

OUT.NOMINAL

I

OUT.NOMINAL

CC Deviation

Eff

PF/THD

265V Maximum Input Voltage

IN.MAX

IN.NOMINAL

110V/220V Nominal Input Voltage

fIN 60Hz/50Hz Line Frequency

V

11V Minimum Output Voltage

OUT.MIN

28V Maximum Output Voltage

OUT.MAX

24V Nominal Output Voltage

700mA Nominal Output Current

< ±2.94% Line Input Voltage Change: 90~265V

< ±2.88% Output Voltage Change: 11~28V

Eff

90VAC

120VAC

140VAC

180VAC

220VAC

87.87% Efficiency at 265VAC Line Input Voltage

265VAC

90VAC

120VAC

140VAC

180VAC

230VAC

265VAC

T

54.7ºC

FL7732

T

63.0ºC Primary MOSFET Temperature

MOSFET

T

70.5ºC Secondary Diode Temperature

DIODE

86.45% Efficiency at 90VAC Line Input Voltage

88.45% Efficiency at 120VAC Line Input Voltage

88.76% Efficiency at 140VAC Line Input Voltage

89.03% Efficiency at 180VAC Line Input Voltage

88.77% Efficiency at 220VAC Line Input Voltage

0.984/15.29% PF/THD at 90VAC Line Input Voltage

0.986/14.27% PF/THD at 120VAC Line Input Voltage

0.984/13.61% PF/THD at 140VAC Line Input Voltage

0.978/14.12% PF/THD at 180VAC Line Input Voltage

0.955/17.69% PF/THD at 230VAC Line Input Voltage

0.936/19.91% PF/THD at 265VAC Line Input Voltage

Open-Frame Condition

(T

= 25ºC) FL7732 Temperature

A

AC

Transformer

T

TRANSFORMER

59.7ºC Transformer Temperature

All data of the evaluation board were measured under a condition where the board was enclosed in a case and external temperature was around 25°C.

2.1. Evaluation Board

Figure 2. Top View (Dimensions:79mm (L) x 30mm (W) x 20mm (H))

Figure 3. Bottom Views (Dimensions:79mm (L) x 30mm (W) x 20mm (H))