LM5045SQ Datasheet, PDF (1/38 Pages) Texas Instruments – Full-Bridge PWM Controller with Integrated MOSFET Drivers

LM5045
www.ti.com
SNVS699G – FEBRUARY 2011 – REVISED MARCH 2013
Full-Bridge PWM Controller with Integrated MOSFET Drivers
Check for Samples: LM5045
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
Synchronous Rectifier dead-time Adjustments
• 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
DESCRIPTION
The LM5045 PWM controller contains all of the
features necessary to implement Full-Bridge topology
power converters 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 brige
MOSFETs plus control signals for the secondary side
synchronous rectifier MOSFETs. External resistors
program the leading and trailing edge dead-time
between the main and synchronous rectifier control
signals. 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.
PACKAGES
• HTSSOP 28 pin
• WQFN 28 pin (5mm x 5mm)
Simplified Full-Bridge Power Converter
Vin
Vout
T1
VCC
T1
VCC
HO1 BST1 HS1 LO1 SLOPE RAMP CS LO2 HS2 BST2 HO2
VIN
UVLO
OVP
VCC
SR1
LM5045 FULL-BRIDGE CONTROLLER ^SR2
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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