Vout

T1

T1

Vin

ISOLATED

FEEDBACK

SSOFF

VCC

REF

AGND

PGND

SS

RES

RT

UVLO

VIN

HO1

BST1 HS1 LO1

CS

LO2

HS2 BST2 HO2

COMP

LM5046 PHASE-SHIFTED

FULL-BRIDGE CONTROLLER

WITH INTEGRATED GATE DRIVERS

RD1

RD2

GATE

DRIVE

ISOLATION

SR1

SR2

VCC

VCC

ISOLATION

BOUNDARY

SLOPE RAMP

SSSR

OVP

Q1

Q2

Q3

Q4

LM5046

www.ti.com

SNVS703G – FEBRUARY 2011 – REVISED MARCH 2013

LM5046 Phase-Shifted Full-Bridge PWM Controller with Integrated MOSFET Drivers

Check for Samples: LM5046

1

FEATURES

PACKAGES

2

•

Highest Integration Controller for Small Form

•

TSSOP-28

Factor, High Density Power Converters

•

WQFN-28 (5mm x 5mm)

•

High Voltage Start-up Regulator

DESCRIPTION

•

Intelligent Sync Rectifier Start-up Allows

The LM5046 PWM controller contains all of the

Linear Turn-on into Pre-biased Loads

features necessary to implement a Phase-Shifted

•

Synchronous Rectifiers Disabled in UVLO

Full-Bridge topology power converter using either

mode and Hiccup Mode

current mode or voltage mode control. This device is

•

Two Independent, Programmable Dead-Time

intended to operate on the primary side of an isolated

Adjustments to Enable Zero-Volt Switching.

dc-dc converter with input voltage up to 100V. This

highly integrated controller-driver provides dual 2A

•

Four High Current 2A Bridge Gate Drivers

high and low side gate drivers for the four external

•

Wide-Bandwidth Opto-coupler Interface

bridge

MOSFETs,

plus

control

signals

for

the

•

Configurable for either Current Mode or

secondary side synchronous rectifier MOSFETs.

Voltage Mode Control

External resistors program the dead-time to enable

zero-volt switching of the primary FETs. Intelligent

•

Dual-mode Over-Current Protection

startup of the synchronous rectifiers allows monotonic

•

Resistor Programmed 2MHz Oscillator

turn-on of the power converter even with pre-bias

•

Programmable Line UVLO and OVP

load conditions. Additional features include cycle-by-

cycle

current

limiting,

hiccup

mode

restart,

programmable soft-start, synchronous rectifier soft-

start

and

a

2

MHz

capable

oscillator

with

synchronization capability and thermal shutdown.

Simplified Phase-Shifted Full-Bridge Power Converter

1

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Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2

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PRODUCTION DATA information is current as of publication date.

Copyright © 2011–2013, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.