LM3743_15 Datasheet, PDF (1/38 Pages) Texas Instruments – High-Performance Synchronous Buck Controller with Comprehensive Fault Protection Features

LM3743
www.ti.com
SNVS427E – SEPTEMBER 2006 – REVISED APRIL 2013
LM3743 High-Performance Synchronous Buck Controller with Comprehensive Fault
Protection Features
Check for Samples: LM3743
FEATURES
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•2 Input Voltage From 3.0V to 5.5V
• Output Voltage Adjustable Down to 0.8V
• Reference Accuracy: ±1.75%, over Full
Temperature and Input Voltage Range
• High-Side and Low-Side N-Channel MOSFETs
• Switching Frequency Options of 1 MHz or 300
kHz
• Comprehensive Fault Protection Features:
– High-Side Current Limit
– Low-Side Current Limit
– Output Under-Voltage Protection
• Hiccup Mode Protection Eliminates Thermal
Runaway During Fault Conditions
• Externally Programmable Soft-Start with
Tracking Capability
• Pre-Bias Start-Up Capability
• VSSOP-10 Package
DESCRIPTION
The LM3743 is a DC-DC voltage mode PWM buck
controller featuring synchronous rectification at 300
kHz or 1 MHz. It can deliver current as high as 20A
and step down from an input voltage between 3V and
5.5V down to a minimum output voltage of 0.8V, with
a ±1.75% internal reference accuracy. The LM3743
provides a set of comprehensive fault protection
features such as high-side current limit, output under-
voltage protection, and low-side current limit. When
any of these fault protection features are engaged, it
enters a hiccup protection mode which is suitable for
high reliability systems such as rack mounted servers
and telecom base station subsystems. The LM3743
also employs a proprietary monolithic glitch free pre-
bias start-up method suited for FPGA and ASIC logic
devices. An external programmable soft-start allows
for tracking and timing flexibility. The driver features
1.6Ω of pull-up resistance and 1Ω of pull-down drive
resistance for high power density and very efficient
power processing.
APPLICATIONS
• Rack-Mount Servers
• Telecom Base Stations
• Routers
• Printers/Scanners
• Multi-Media Set-Top Boxes
• FPGAs, ASICs, and DSPs
Typical Application
D1
VIN
R6
BOOT
VCC
C10
HGATE
+
Q1 ^C1
+
C2
C3
SW
LM3743 _ILIM
R1
L1
VOUT
SS/TRACK
LGATE
C4
GND
COMP/EN
FB
C7
Q2
R5
C8
+ _C5
R2
C9
R4
R3
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Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
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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 © 2006–2013, Texas Instruments Incorporated