LM3103 Datasheet, PDF (1/16 Pages) National Semiconductor (TI) – SIMPLE SWITCHER® Synchronous 1MHz 0.75A Step-Down Voltage Regulator

October 2007
LM3103
SIMPLE SWITCHER® Synchronous 1MHz 0.75A
Step-Down Voltage Regulator
General Description
The LM3103 Synchronously Rectified Buck Converter fea-
tures all required functions to implement a highly efficient and
cost effective buck regulator. It is capable of supplying 0.75A
to loads with an output voltage as low as 0.6V. Dual N-Chan-
nel 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, re-
sults in a fast load transient response and simple circuit
implementation. The operating frequency remains nearly con-
stant with line variations due to the inverse relationship be-
tween the input voltage and the on-time. The operating
frequency can be externally programmed up to 1 MHz. Pro-
tection features include V_CC under-voltage lock-out, output
over-voltage protection, thermal shutdown, and gate drive
under-voltage lock-out. The LM3103 is available in the ther-
mally enhanced eTSSOP-16 package.
Key Specifications
■ ^{Input voltage range 4.5V-42V}
■ ^{0.75A output current}
■ ^{0.6V, ±2% reference}
■ ^{Integrated dual N-Channel main and synchronous}
MOSFETs
■ ^{Thermally enhanced eTSSOP-16 package}
Features
■ ^{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 0.6V
Typical 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
Typical Application
SIMPLE SWITCHER® is a registered trademark of National Semiconductor Corporation
© 2007 National Semiconductor Corporation 300297
30029701
www.national.com