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.