May 2010

© 2009 Fairchild Semiconductor Corporation

www.fairchildsemi.com

FSFR-US Series • Rev.1.0.2

for Half-Bridge Resonant Converters

Features

Variable Frequency Control with 50% Duty Cycle

for Half-Bridge Resonant Converter Topology

High Efficiency through Zero Voltage Switching (ZVS)

Internal UniFET™s with Fast-Recovery Type

Body Diode

Fixed Dead Time (350ns) Optimized for MOSFETs

Up to 300kHz Operating Frequency

Auto-Restart Operation for All Protections with An

Protection Functions: Over-Voltage Protection

(OVP), Over-Current Protection (OCP), Abnormal

Over-Current Protection (AOCP), Internal Thermal

Shutdown (TSD)

Applications

PDP and LCD TVs

Desktop PCs and Servers

Adapters

Telecom Power Supplies

Description

The FSFR-US series are a highly integrated power

switches

designed

for

high-efficiency

half-bridge

resonant converters. Offering everything necessary to

build a reliable and robust resonant converter, the FSFR-

US series simplifies designs and improves productivity,

while improving performance. The FSFR-US series

combines power MOSFETs with fast-recovery type body

diodes, a high-side gate-drive circuit, an accurate current

controlled oscillator, frequency limit circuit, soft-start, and

built-in protection functions. The high-side gate-drive

circuit has a common-mode noise cancellation capability,

which guarantees stable operation with excellent noise

immunity. The fast-recovery body diode of the MOSFETs

improves

reliability

against

abnormal

operation

conditions, while minimizing the effect of the reverse

recovery.

Using

the

zero-voltage-switching

(ZVS)

technique dramatically reduces the switching losses and

efficiency is significantly improved. The ZVS also

reduces the switching noise noticeably, which allows a

small-sized Electromagnetic Interference (EMI) filter.

The FSFR-US series can be applied to various resonant

converter topologies such as series resonant, parallel

resonant, and LLC resonant converters.

Related Resources

AN4151 — Half-bridge LLC Resonant Converter Design

using FSFR-Series Fairchild Power Switch (FPS

Ordering Information

Part Number

Package

Operating

Junction

Temperature

Maximum Output Power

without Heatsink

(1,2)

Maximum Output

Power with Heatsink

(1,2)

FSFR2100US

9-SIP

-40 to +130°C

0.51

Ω

180W

400W

FSFR1800US

0.95

Ω

120W

260W

FSFR1700US

1.25

Ω

100W

200W

FSFR2100USL

9-SIP

L-Forming

0.51

Ω

180W

400W

FSFR1800USL

0.95

Ω

120W

260W

FSFR1700USL

1.25

Ω

100W

200W

Notes:

1.

The junction temperature can limit the maximum output power.

2.

Maximum practical continuous power in an open-frame design at 50

°C ambient.