FAN7631 Datasheet, PDF (1/19 Pages) Fairchild Semiconductor – Advanced Pulse Frequency Modulation (PFM) Controller for Half-Bridge Resonant Converters

April 2012
FAN7631
Advanced Pulse Frequency Modulation (PFM)
Controller for Half-Bridge Resonant Converters
Features
 Variable Frequency Control with 50% Duty Cycle
for Half-Bridge Resonant Converter Topologies
 High Efficiency with Zero-Voltage-Switching (ZVS)
 Up to 600kHz Operating Frequency
 Built-in High-Side Gate Driver
 High Gate-Driving Current: +500mA/-1000mA
 Programmable Dead Time with a Resistor
 Pulse Skipping and Burst Operation for Frequency
Limit (Programmable) at Light-Load Condition
 Simple Remote On/Off Control with Latch or
Auto-Restart (A/R) Using FI or LS Pin
 Protection Functions: Over-Voltage Protection
(OVP), Overload Protection (OLP), Over-Current
Protection (OCP), Abnormal Over-Current Protection
(AOCP), Internal Thermal Shutdown (TSD), and
High Precise Line Under-Voltage Lockout (LUVLO)
 Level-Change OCP Function During Startup
Applications
 PDP and LCD TVs
 Desktop PCs and Servers
 Video Game Consoles
 Adapters
 Telecom Power Supplies
Description
The FAN7631 is a pulse-frequency modulation controller
for high-efficiency half-bridge resonant converters that
includes a high-side gate drive circuit, an accurate
current-controlled oscillator, and various protection
functions. The FAN7631 features include variable dead
time, operating frequency up to 600kHz, protections such
as LUVLO, and a selectable latch or A/R protection using
the LS pin for user convenience.
The Zero-Voltage-Switching (ZVS) technique reduces the
switching losses and improves the efficiency significantly.
ZVS also reduces the switching noise noticeably, which
allows a small Electromagnetic Interference (EMI) filter.
Offering everything necessary to build a reliable and
robust resonant converter, the FAN7631 simplifies
designs and improves productivity and performance. The
FAN7631 can be applied to 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
Operating Junction
Temperature
FAN7631SJ
FAN7631SJX
-40C ~ 130C
Package
16-Lead, Small-Outline Package (SOP)
Packaging
Method
Tube
Tape & Reel
© 2011 Fairchild Semiconductor Corporation
FAN7631 • 1.0.2
www.fairchildsemi.com