LM5046SQX Datasheet, PDF (1/41 Pages) Texas Instruments – LM5046 Phase-Shifted Full-Bridge PWM Controller with Integrated MOSFET Drivers

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
FEATURES
1
•2 Highest Integration Controller for Small Form
Factor, High Density Power Converters
• High Voltage Start-up Regulator
• Intelligent Sync Rectifier Start-up Allows
Linear Turn-on into Pre-biased Loads
• Synchronous Rectifiers Disabled in UVLO
mode and Hiccup Mode
• Two Independent, Programmable Dead-Time
Adjustments to Enable Zero-Volt Switching.
• Four High Current 2A Bridge Gate Drivers
• Wide-Bandwidth Opto-coupler Interface
• Configurable for either Current Mode or
Voltage Mode Control
• Dual-mode Over-Current Protection
• Resistor Programmed 2MHz Oscillator
• Programmable Line UVLO and OVP
PACKAGES
• TSSOP-28
• WQFN-28 (5mm x 5mm)
DESCRIPTION
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-
start and a 2 MHz capable oscillator with
synchronization capability and thermal shutdown.
Simplified Phase-Shifted Full-Bridge Power Converter
Vin
Vout
Q1
Q3
T1
T1
VCC
Q2
Q4
VCC
HO1 BST1 HS1 LO1 SLOPE RAMP CS LO2 HS2 BST2 HO2
VIN
UVLO
OVP
VCC
SR1
LM5046 PHASE-SHIFTED
SR2
FULL-BRIDGE CONTROLLER
WITH INTEGRATED GATE DRIVERS
SSOFF
COMP
RT RES SS SSSR RD1 RD2 REF PGND AGND
GATE
DRIVE
ISOLATION
ISOLATED
FEEDBACK
ISOLATION
BOUNDARY
1
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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.
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