IRAC11662-100W

IRAC11662-100W Datasheet

IRAC11662-100W

Part	Datasheet
IRAC11662-100W	IRAC11662-100W (pdf)

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User Guide IRAC11662-100W +16V Low-side Smart Rectification 100W Flyback Demo Board User’s Guide by HELEN DING, ISRAEL SERRANO 19 April 2010 19 April 2010 Page 1 of 24 WORLD HEADQUARTERS 233 Kansas St., El Segundo, California 90245 Tel 310 252-7105 Data and specifications subject to change without notice. Table of Contents INTRODUCTION GENERAL DESCRIPTION IRAC11662-100W +16V Demo Board Schematic Diagram IRAC11662-100W +16V Demo Board Pictures IRAC11662-100W +16V Demo Board PCB Layout Circuit Description Test Connection and Set up Pictures Circuit Features OVT Setting ENABLE Setting MOT Setting Mosfet Selection Design Tips Test Waveforms Transient Load Test Static Load Test Ripple And Noise Measurement Dynamic load Test Line / Load Regulation Test IR11662 Demo Board V-I Characteristics Curve System Efficiency Test Thermal Verification Summary Appendix Transformer turns ratio, Duty Cycle and Secondary Current Relationship Chart IR11662 100W +16V SR Demo Board Power Transformer Specs IRAC11662-100W +16V Demo Board Bill of Materials BOM Page s 2 3 4 5 6 7 8 9 10 11-17 11-13 14-15 16 17 18 19 20 21-25 21 22 23-24 19 April 2010 Page 2 of 24 WORLD HEADQUARTERS 233 Kansas St., El Segundo, California 90245 Tel 310 252-7105 Data and specifications subject to change without notice. INTRODUCTION Generally, Schottky diodes are traditional devices use in passive rectification in order to have low conduction loss in secondary side for switching power supplies. The proliferations of synchronous rectification SR idea - which is mostly use in buck-derive topologies - have reached the domain of flyback application in recent years. The use of low-voltage-low-Rdson mosfet has become so attractive to replace the Schottky rectifiers in high current applications because it offers several system advantages such as dramatic decrease in conduction loss and better thermal management of the whole system by reducing the cost investment in heat sink and PCB space. The objective of this user guide is to show the advantages of SR application using integrated IC approach and study the practical limits of the efficiency improvements vs. the normal rectification method. The IRAC11662-100W demo board is a universal-input flyback converter with single DC output capable of delivering continuous 100W +16V x 6.25A during active rectification mode. This demo board is primarily designed to study synchronous rectification using IR11662 in low-side configuration to take advantage of simpler derivation of Vcc supply from converter’s output. It is equipped with necessary jumpers to ease exploring the conduction behavior of synchronous rectifiers SRs in quasi-resonant mode, so discussion would be confined to variable frequency switching in Critical Conduction Mode. It features the fast Vsd sensing of the IR11662 Smart Rectifier Control IC with gate output drive capability of +1A/-4A. It drives 2 pcs. of SRs in parallel 100V N-ch mosfet IRF7853 in SO-8 package with very low Rdson in its class 18 max . This had greatly simplified the overall mechanical design for not having those bulky and heavy heat sinks normally seen in high current flyback design using passive rectification. 19 April 2010 Page 3 of 24 WORLD HEADQUARTERS 233 Kansas St., El Segundo, California 90245 Tel 310 252-7105 Data and specifications subject to change without notice. FIGURE IRAC11662-100W SCHEMATIC DIAGRAM Vout-tp 1000UF/25V 1500UF/25V 1500UF/25V 19 April 2010 WORLD HEADQUARTERS 233 Kansas St., El Segundo, California 90245 Tel 310 252-7105 IRAC1166-100W +16V Demo Board Schematic Diagram CON1 3 1 F1 FUSE Cp1 220NF/275V 10R NTC Thermistor 6GBU06 4N7/1kV 4N7/1kV 330UF/400V Dp1 1N5407 Rp2 47K 2W 2

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User Guide

IRAC11662-100W
+16V Low-side Smart Rectification 100W Flyback Demo Board User’s Guide
by HELEN DING, ISRAEL SERRANO
19 April 2010
19 April 2010

Page 1 of 24

WORLD HEADQUARTERS 233 Kansas St., El Segundo, California 90245 Tel 310 252-7105

Data and specifications subject to change without notice.

Table of Contents INTRODUCTION GENERAL DESCRIPTION IRAC11662-100W +16V Demo Board Schematic Diagram IRAC11662-100W +16V Demo Board Pictures IRAC11662-100W +16V Demo Board PCB Layout Circuit Description Test Connection and Set up Pictures Circuit Features OVT Setting ENABLE Setting MOT Setting Mosfet Selection Design Tips Test Waveforms Transient Load Test Static Load Test Ripple And Noise Measurement Dynamic load Test Line / Load Regulation Test IR11662 Demo Board V-I Characteristics Curve System Efficiency Test Thermal Verification Summary Appendix Transformer turns ratio, Duty Cycle and Secondary Current Relationship Chart IR11662 100W +16V SR Demo Board Power Transformer Specs IRAC11662-100W +16V Demo Board Bill of Materials BOM

Page s 2 3 4 5 6 7 8 9 10 11-17 11-13 14-15 16 17 18 19 20 21-25 21
22 23-24
19 April 2010

Page 2 of 24

WORLD HEADQUARTERS 233 Kansas St., El Segundo, California 90245 Tel 310 252-7105

Data and specifications subject to change without notice.

INTRODUCTION

Generally, Schottky diodes are traditional devices use in passive rectification in order to have low conduction loss in secondary side for switching power supplies. The proliferations of synchronous rectification SR idea - which is mostly use in buck-derive topologies - have reached the domain of flyback application in recent years. The use of low-voltage-low-Rdson mosfet has become so attractive to replace the Schottky rectifiers in high current applications because it offers several system advantages such as dramatic decrease in conduction loss and better thermal management of the whole system by reducing the cost investment in heat sink and PCB space.

The objective of this user guide is to show the advantages of SR application using integrated IC approach and study the practical limits of the efficiency improvements vs. the normal rectification method.

The IRAC11662-100W demo board is a universal-input flyback converter with single DC output capable of delivering continuous 100W +16V x 6.25A during active rectification mode. This demo board is primarily designed to study synchronous rectification using IR11662 in low-side configuration to take advantage of simpler derivation of Vcc supply from converter’s output. It is equipped with necessary jumpers to ease exploring the conduction behavior of synchronous rectifiers SRs in quasi-resonant mode, so discussion would be confined to variable frequency switching in Critical Conduction Mode.

It features the fast Vsd sensing of the IR11662 Smart Rectifier Control IC with gate output drive capability of +1A/-4A. It drives 2 pcs. of SRs in parallel 100V N-ch mosfet IRF7853 in SO-8 package with very low Rdson in its class 18 max . This had greatly simplified the overall mechanical design for not having those bulky and heavy heat sinks normally seen in high current flyback design using passive rectification.
19 April 2010

Page 3 of 24

WORLD HEADQUARTERS 233 Kansas St., El Segundo, California 90245 Tel 310 252-7105

Data and specifications subject to change without notice.

FIGURE IRAC11662-100W SCHEMATIC DIAGRAM

Vout-tp
1000UF/25V 1500UF/25V 1500UF/25V
19 April 2010

WORLD HEADQUARTERS 233 Kansas St., El Segundo, California 90245 Tel 310 252-7105

IRAC1166-100W +16V Demo Board Schematic Diagram

CON1 3 1

F1 FUSE

Cp1 220NF/275V
10R NTC Thermistor
6GBU06
4N7/1kV
4N7/1kV
330UF/400V

Dp1 1N5407

Rp2 47K 2W 2

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Datasheet ID: IRAC11662-100W 638306