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 softstart

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.