1 Features

1• Input Voltage Range 4.5 V to 42 V

• 0.75 A Output Current

• 0.6V, ±2% Reference

• Integrated Dual N-Channel Main and

Synchronous MOSFETs

• Low Component Count and Small Solution Size

• Stable with Ceramic and Other Low ESR

Capacitors

• No Loop Compensation Required

• High Efficiency at a Light Load by DCM Operation

• Pre-bias Startup

• Ultra-Fast Transient Response

• Programmable Soft-Start

• Programmable Switching Frequency up to 1 MHz

• Valley Current Limit

• Thermal Shutdown

• Output Over-Voltage Protection

• Precision Internal Reference for an Adjustable

Output Voltage Down to 0.6 V

• Thermally Enhanced HTSSOP-16 Package

2 Applications

• 5VDC, 12VDC, 24VDC, 12VAC, and 24VAC

Systems

• Embedded Systems

• Industrial Control

• Automotive Telematics and Body Electronics

• Point of Load Regulators

• Storage Systems

• Broadband Infrastructure

• Direct Conversion from 2,3,4 Cell Lithium

Batteries Systems

3 Description

The LM3103 Synchronously Rectified Buck Converter

features all required functions to implement a highly

efficient and cost effective buck regulator. It is

capable of supplying 0.75 A to loads with an output

voltage as low as 0.6 V. Dual N-Channel

synchronous MOSFET switches allow a low

component count, thus reducing complexity and

minimizing board size.

Different from most other COT regulators, the

LM3103 does not rely on output capacitor ESR for

stability, and is designed to work exceptionally well

with ceramic and other very low ESR output

capacitors. It requires no loop compensation, results

in a fast load transient response and simple circuit

implementation. The operating frequency remains

nearly constant with line variations due to the inverse

relationship between the input voltage and the ontime.

The operating frequency can be externally

programmed up to 1 MHz. Protection features include

VCC under-voltage lock-out, output over-voltage

protection, thermal shutdown, and gate drive undervoltage

lock-out. The LM3103 is available in the

thermally enhanced HTSSOP-16 package.