LM2833 Datasheet, PDF (1/22 Pages) National Semiconductor (TI) – 1.5MHz/3MHz 3.0A Step-Down DC-DC Switching Regulator

January 13, 2009
LM2833
1.5MHz/3MHz 3.0A Step-Down DC-DC Switching Regulator
General Description
The LM2833 regulator is a monolithic, high frequency, PWM
step-down DC/DC converter available in a 10-pin LLP or eM-
SOP package. It contains all the active functions to provide
local DC/DC conversion with fast transient response and ac-
curate regulation in the smallest possible PCB area. With a
minimum of external components, the LM2833 is easy to use.
The ability to drive 3.0A loads with an internal 56 mΩ PMOS
switch using state-of-the-art 0.5µm BiCMOS technology re-
sults in the best power density available. The world-class
control circuitry allows on-times as low as 30ns, thus sup-
porting exceptionally high frequency conversion over the en-
tire 3V to 5.5V input operating range down to the minimum
output voltage of 0.6V. Switching frequency is internally set
to 1.5MHz or 3.0MHz, allowing the use of extremely small
surface mount inductors and capacitors. Even though the op-
erating frequency is high, efficiencies up to 93% are easy to
achieve. External shutdown is included, featuring an ultra-low
stand-by current of 300nA. The LM2833 utilizes peak current-
mode control and internal compensation to provide high-
performance regulation over a wide range of operating
conditions. Additional features include internal soft-start cir-
cuitry to reduce inrush current, cycle-by-cycle current limit,
frequency foldback, thermal shutdown, and output over-volt-
age protection.
Features
■ ^{Input voltage range of 3.0V to 5.5V}
■ ^{Output voltage range of 0.6V to 4.5V}
■ ^{Tiny eMSOP-10 or LLP-10 package}
■ ^{3.0A steady-state output current}
■ ^{High switching frequencies}
1.5MHz (LM2833X)
3.0MHz (LM2833Z)
■ ^{Enable pin}
■ ^{56mΩ PMOS switch}
■ ^{0.6V, 2% internal voltage reference over line and}
temperature
■ ^{Internal soft-start}
■ ^{Internally compensated peak current-mode control}
■ ^{Cycle-by-cycle current limit and thermal shutdown}
■ ^{Frequency foldback protection}
■ ^{Input voltage UVLO (Under-voltage lockout)}
■ ^{Output over-voltage protection}
Applications
■ ^{Multimedia Set Top Box}
■ ^{Broadband Communications}
■ ^{Core Power in HDDs}
■ ^{Data Acquisition/Telemetry}
■ ^{USB Powered Devices}
■ ^{DSL Modems}
Typical Application Circuit
30013201
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