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.