LM1572
1.5A, 500kHz Step-down Voltage Regulator
General Description
Features
The LM1572 is a 500kHz step-down (buck) switching voltage regulator capable of driving up to 1.5A in to a load while
occupying a very small PCB area. Current Mode Control
results in superior transient response and regulation over a
wider range of operating conditions. National’s advanced
analog bipolar, CMOS plus DMOS process enables high
efficiency at high switching frequency, and the internal
150mΩ MOSFET switch provides more power from a
smaller package.
The LM1572 has programmable soft-start and frequency
foldback to limit the inrush current, and a TTL compatible
shutdown for easy sequencing. It draws 2.3mA of supply
current in standby mode, and only 26µA in shutdown mode.
The LM1572 is available in a TSSOP-16 package with an
adjustable output or fixed outputs of 5V and 3.3V. The adjustable version can be set between 2.42V and 5V.
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500kHz clock allows small, surface mount components
150mΩ MOSFET switch
Guaranteed load current of 1.5A
Current mode control
Programmable soft-start
Internally set slope compensation
TTL compatible shutdown
Fixed 5V, 3.3V or adjustable output
Low shutdown supply current of 26µA
Cycle-by-cycle current limit
Short-circuit protection and thermal protection
TSSOP-16 package
Applications
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LCD Monitors and TVs
Set-Top Boxes
Cable Modems
Down conversion from 12V in local/distributed systems
Typical Applications (Fixed/Adjustable Voltage Parts)
20033313
© 2002 National Semiconductor Corporation
DS200333
www.national.com
LM1572 1.5A, 500kHz Step-down Voltage Regulator
July 2002
