LM2743_14 Datasheet, PDF (1/37 Pages) Texas Instruments – Low Voltage N-Channel MOSFET Synchronous Buck Regulator Controller

LM2743
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SNVS276F – MAY 2004 – REVISED JANUARY 2012
LM2743 Low Voltage N-Channel MOSFET Synchronous Buck Regulator Controller
Check for Samples: LM2743
FEATURES
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•2 Power stage input voltage from 1V to 16V
• Control stage input voltage from 3V to 6V
• Output voltage adjustable down to 0.6V
• Power good flag and shutdown
• Output over-voltage and under-voltage
detection
• ±2% feedback voltage accuracy over
temperature
• Low-side adjustable current sensing
• Adjustable soft-start
• Tracking and sequencing with shutdown and
soft-start pins
• Switching frequency from 50 kHz to 1 MHz
• TSSOP-14 package
APPLICATIONS
• 3.3V Buck Regulation
• Cable Modem, DSL and ADSL
• Laser Jet and Ink Jet Printers
• Low Voltage Power Modules
• DSP, ASIC, Core and I/O
DESCRIPTION
The LM2743 is a high-speed synchronous buck regulator controller with an accurate feedback voltage accuracy
of ±2%. It can provide simple down conversion to output voltages as low as 0.6V. Though the control sections of
the IC are rated for 3 to 6V, the driver sections are designed to accept input supply rails as high as 16V. The use
of adaptive non-overlapping MOSFET gate drivers helps avoid potential shoot-through problems while
maintaining high efficiency. The IC is designed for the more cost-effective option of driving only N-channel
MOSFETs in both the high-side and low-side positions. It senses the low-side switch voltage drop for providing a
simple, adjustable current limit.
The fixed-frequency voltage-mode PWM control architecture is adjustable from 50 kHz to 1 MHz with one
external resistor. This wide range of switching frequency gives the power supply designer the flexibility to make
better tradeoffs between component size, cost and efficiency.
Features include soft-start, input under-voltage lockout (UVLO) and Power Good (based on both under-voltage
and over-voltage detection). In addition, the shutdown pin of the IC can be used for providing startup delay, and
the soft-start pin can be used for implementing precise tracking, for the purpose of sequencing with respect to an
external rail.
Typical Application
V_CC = 3.3V
D₁
C_BOOT
V_IN = 3.3V
R_CC
R_PULL-UP
C_CC
R_FADJ
C_SS
V_CC
SD
PWGD
FREQ
LM2743
SS/TRACK
SGND
EAO
HG
BOOT
I_SEN
LG
PGND
PGND
FB
C_C2
C_C1
R_C1
Q1
R_CS
L1
R_C2
C_C3
+ _CIN1,2
V_OUT = 1.2V@4A
R_FB2
+
C_O1,2
R_FB1
Figure 1. Typical Application Circuit
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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 © 2004–2012, Texas Instruments Incorporated