LM5046
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SNVS703G –FEBRUARY 2011–REVISED MARCH 2013
LM5046 Phase-Shifted Full-Bridge PWM Controller with Integrated MOSFET Drivers
Check for Samples: LM5046
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FEATURES
PACKAGES
2
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Highest Integration Controller for Small Form
Factor, High Density Power Converters
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TSSOP-28
WQFN-28 (5mm x 5mm)
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High Voltage Start-up Regulator
DESCRIPTION
Intelligent Sync Rectifier Start-up Allows
Linear Turn-on into Pre-biased Loads
The LM5046 PWM controller contains all of the
features necessary to implement a Phase-Shifted
Full-Bridge topology power converter using either
current mode or voltage mode control. This device is
intended to operate on the primary side of an isolated
dc-dc converter with input voltage up to 100V. This
highly integrated controller-driver provides dual 2A
high and low side gate drivers for the four external
bridge MOSFETs, plus control signals for the
secondary side synchronous rectifier MOSFETs.
External resistors program the dead-time to enable
zero-volt switching of the primary FETs. Intelligent
startup of the synchronous rectifiers allows monotonic
turn-on of the power converter even with pre-bias
load conditions. Additional features include cycle-by-
cycle current limiting, hiccup mode restart,
programmable soft-start, synchronous rectifier soft-
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Synchronous Rectifiers Disabled in UVLO
mode and Hiccup Mode
Two Independent, Programmable Dead-Time
Adjustments to Enable Zero-Volt Switching.
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Four High Current 2A Bridge Gate Drivers
Wide-Bandwidth Opto-coupler Interface
Configurable for either Current Mode or
Voltage Mode Control
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Dual-mode Over-Current Protection
Resistor Programmed 2MHz Oscillator
Programmable Line UVLO and OVP
start and
a
2
MHz capable oscillator with
synchronization capability and thermal shutdown.
Simplified Phase-Shifted Full-Bridge Power Converter
Vin
Vout
Q3
Q4
Q1
Q2
T1
T1
VCC
VCC
HO1 BST1
VIN
LO1 SLOPE RAMP CS LO2 HS2 BST2 HO2
HS1
GATE
DRIVE
ISOLATION
SR1
UVLO
OVP
LM5046 PHASE-SHIFTED
FULL-BRIDGE CONTROLLER
SR2
VCC
WITH INTEGRATED GATE DRIVERS
ISOLATED
FEEDBACK
COMP
SSOFF
RT
RES
SS
RD1 RD2 REF PGND AGND
SSSR
ISOLATION
BOUNDARY
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2
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2011–2013, Texas Instruments Incorporated