LM2743MTCX Datasheet, PDF (1/37 Pages) Texas Instruments – LM2743 Low Voltage N-Channel MOSFET Synchronous Buck Regulator Controller

LM2743
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SNVS276G – APRIL 2004 – REVISED MARCH 2013
LM2743 Low Voltage N-Channel MOSFET Synchronous Buck Regulator Controller
Check for Samples: LM2743
FEATURES
1
•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.
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