LM3100_07 Datasheet, PDF (1/18 Pages) National Semiconductor (TI) – SIMPLE SWITCHER® Synchronous 1MHz 1.5A Step-Down Voltage Regulator

August 2007
LM3100
SIMPLE SWITCHER® Synchronous 1MHz 1.5A Step-Down
Voltage Regulator
General Description
The LM3100 Synchronously Rectified Buck Converter fea-
tures all functions needed to implement a highly efficient, cost
effective buck regulator capable of supplying 1.5A to loads
with voltages as low as 0.8V. Dual 40V N-Channel syn-
chronous MOSFET switches allow for low external compo-
nent thus reducing complexity and minimizing board space.
The LM3100 is designed to work exceptionally well with ce-
ramic and other very low ESR output capacitors. The Con-
stant ON-Time (COT) regulation scheme requires no loop
compensation, results in fast load transient response, and
simplifies circuit implementation. Through the use of a unique
design the regulator does not rely on output capacitor ESR
for stability, as do most other COT regulators. The operating
frequency remains nearly constant with line and load varia-
tions due to the inverse relationship between the input voltage
and the on-time. The oprating frequency can be externally
programmed up to 1MHz. Protection features include V_CC un-
der-voltage lockout, thermal shutdown and gate drive under-
voltage lockout. The part is available in a thermally enhanced
eTSSOP-20 package
Features
■ ^{Input voltage range 4.5V - 36V}
■ ^{1.5A output current}
■ ^{0.8V, ±1.5% reference}
■ ^{Integrated 40V, dual N-Channel buck synchronous}
switches
■ ^{Low component count and small solution size}
■ ^{No loop compensation required}
■ ^{Ultra-fast transient response}
■ ^{Stable with ceramic and other low ESR capacitors}
■ ^{Programmable switching frequency up to 1MHz}
■ ^{Max. duty cycle limited during start-up}
■ ^{Valley current limit}
■ ^{Precision Internal Reference for adjustable output voltage}
down to 0.8V
■ ^{Thermal shutdown}
■ ^{Thermally enhanced eTSSOP-20 package}
Typical Applications
■ ^{5VDC, 12VDC, 24VDC, 12VAC, and 24VAC systems}
■ ^{Embedded Systems}
■ ^{Industrial Controls}
■ ^{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
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