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Design DocumentAnalog

DC1947A: LT3799-1 Offline Isolated Flyback LED Driver with PFC

1A offline isolated flyback LED driver using LT3799-1. Supports 30V-50V LED strings and 90-277VAC input with >0.9 power factor and primary-side sensing.

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Overview

The DC1947A demonstration circuit is an offline isolated flyback LED driver featuring the LT3799-1 controller. It provides a constant current output of 1A over an LED string voltage range of 30V to 50V. The circuit is designed for a universal input voltage range of 90VAC to 277VAC and maintains a power factor greater than 0.9. It utilizes boundary mode operation and primary-side current sensing to eliminate the need for an opto-coupler while maintaining tight regulation. The design is compliant with IEC 61000-3-2 Class C harmonics and EN55015B EMI standards, and includes protection for open-LED and shorted-LED faults.

Use Cases

  • Universal input LED lighting
  • Commercial LED luminaires
  • Industrial lighting applications
  • Offline LED power supplies

Topics

LT3799-1
DC1947A
LED driver
isolated flyback
PFC
power factor correction
boundary mode
primary-side sensing
constant current

Referenced Parts

CMR1U-10M

Central Semiconductor

DIODE, ULTRA FAST RECTIFIER

12061C105KAT2A

AVX

12 1 C23 CAP, X7R, 1μF, 100V, 10%, 1206 AVX 12061C105KAT2A

SS-5H-2.5A

Bussmann

FUSE, 2.5A

BAV20W-7-F

Diodes Inc.

DIODE, FAST SWITCHING

HD06-T

Diodes Inc.

RECTIFIER, BRIDGE 600V, 0.8A

PDU340-13

Diodes Inc.

DIODE, 3A Ultra-Fast REC., Power-DI-5

SMBJ170A-13-F

Diodes Inc.

DIODE, TVS, 600W, 170V, SMB

SMBJ48A-13-F

Diodes Inc.

DIODE, TVS, 600W, 48V, SMB

B82731H2701A030

EPCOS

CHOKE, D Code Double Choke

LT3799EMSE-1#PBF

Linear Technology

IC., Isolated Flyback Controller

63ZL330MEF

Rubycon

CAP, ELEC., 330μF, 63V, 20%

CV385K10R

Stackpole Electronics, Inc.

VARISTOR, 385V

CRCW080510KFKEA

Vishay

RES, CHIP., 10k, 1%, 1/8W, 0805

CRCW080520KFKEA

Vishay

RES, CHIP., 20k, 1%, 1/8W, 0805

CRCW080520R0JKEA

Vishay

RES, CHIP., 20, 5%, 1/8W, 0805

750817251

Wurth Elektronik

XFMR, FLYBACK

LT3799-1

Linear Technology

off-line isolated flyback LED driver featuring LTC® 3799-1

0.8A

Diodes

1 1 B1 RECTIFIER, BRIDGE 600V, 0.8A DIODES INC., HD06-T

Power-DI-5

Diodes

15 1 D3 DIODE, 3A Ultra-Fast REC., Power-DI-5 DIODES INC., PDU340-13

650V

Infineon

21 1 Q1 XSTR, MOSFET, N-CHANNEL 650V INFINEON, IPB60R165CP

1mH

TDK

19 1 L1 INDUCTOR, 1mH, TDK, TSL1315RA-102JR78-PF