HG

BOOT

ISEN

LG

PGND

FB

VCC

SD

PWGD

FREQ

SS/TRACK

SGND

EAO

PGND

VCC = 3.3V

VIN = 3.3V

VOUT = 1.2V@4A

RFB2

CC2

RC1

RCS

CSS

RFADJ

RCC

CCC

D1

CBOOT

Q1

CIN1,2

L1

+

CC1

RFB1

CO1,2

LM2743

RC2

CC3

RPULL-UP

+

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An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,

intellectual property matters and other important disclaimers. PRODUCTION DATA.

LM2743

SNVS276I – APRIL 2004 – REVISED FEBRUARY 2019

LM2743 2.2-V to 16-V Input, voltage mode,

synchronous buck controller with tracking

1

1 Features

1

•

Power stage input voltage from 1 V to 16 V

•

Control stage input voltage from 3 V to 6 V

•

Output voltage adjustable down to 0.6 V

•

Power-good flag and shutdown

•

Output overvoltage and undervoltage 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

•

Create a custom design using the LM2743 with

the WEBENCH® Power Designer

2 Applications

•

3.3-V Buck regulation

•

Cable modem, DSL and ADSL

•

Laser Jet and ink jet printers

•

Low-voltage power modules

•

DSP, ASIC, core, and I/O

3 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 0.6 V.

Though the control sections of the IC are rated for 3

V to 6 V, the driver sections are designed to accept

input supply rails as high as 16 V. 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 undervoltage lockout

(UVLO)

and

Power

Good

(based

on

both

undervoltage and overvoltage detection). In addition,

the shutdown pin of the IC can be used for providing

start-up delay, and the soft-start pin can be used for

implementing precise tracking, for the purpose of

sequencing with respect to an external rail.

Device Information(1)

PART NUMBER

PACKAGE

BODY SIZE (NOM)

LM2743

TSSOP (14)

5.00 mm × 4.40 mm

(1) For all available packages, see the orderable addendum at

the end of the data sheet.

Typical Application Diagram