LM2675_14 Datasheet, PDF (1/30 Pages) Texas Instruments – SIMPLE SWITCHER® Power Converter High Efficiency 1A Step-Down Voltage Regulator

LM2675
www.ti.com
SNVS129E – MAY 2004 – REVISED JUNE 2005
LM2675 SIMPLE SWITCHER^® Power Converter High Efficiency 1A Step-Down Voltage
Regulator
Check for Samples: LM2675
FEATURES
1
•234 Efficiency up to 96%
• Available in SO-8, 8-pin DIP and LLP packages
• Computer Design Software LM267X Made
Simple (version 6.0)
• Simple and easy to design with
• Requires only 5 external components
• Uses readily available standard inductors
• 3.3V, 5.0V, 12V, and adjustable output versions
• Adjustable version output voltage range: 1.21V
to 37V
• ±1.5% max output voltage tolerance over line
and load conditions
• Guaranteed 1A output load current
• 0.25Ω DMOS Output Switch
• Wide input voltage range: 8V to 40V
• 260 kHz fixed frequency internal oscillator
• TTL shutdown capability, low power standby
mode
• Thermal shutdown and current limit protection
TYPICAL APPLICATIONS
• Simple High Efficiency (>90%) Step-Down
(Buck) Regulator
• Efficient Pre-Regulator for Linear Regulators
• Positive-to-Negative Converter
DESCRIPTION
The LM2675 series of regulators are monolithic integrated circuits built with a LMDMOS process. These
regulators provide all the active functions for a step-down (buck) switching regulator, capable of driving a 1A load
current with excellent line and load regulation. These devices are available in fixed output voltages of 3.3V, 5.0V,
12V, and an adjustable output version.
Requiring a minimum number of external components, these regulators are simple to use and include patented
internal frequency compensation (Patent Nos. 5,382,918 and 5,514,947) and a fixed frequency oscillator.
The LM2675 series operates at a switching frequency of 260 kHz, thus allowing smaller sized filter components
than what would be needed with lower frequency switching regulators. Because of its very high efficiency
(>90%), the copper traces on the printed circuit board are the only heat sinking needed.
A family of standard inductors for use with the LM2675 are available from several different manufacturers. This
feature greatly simplifies the design of switch-mode power supplies using these advanced ICs. Also included in
the datasheet are selector guides for diodes and capacitors designed to work in switch-mode power supplies.
Other features include a guaranteed ±1.5% tolerance on output voltage within specified input voltages and output
load conditions, and ±10% on the oscillator frequency. External shutdown is included, featuring typically 50 μA
stand-by current. The output switch includes current limiting, as well as thermal shutdown for full protection under
fault conditions.
To simplify the LM2675 buck regulator design procedure, there exists computer design software, LM267X Made
Simple version 6.0.
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
SIMPLE SWITCHER is a registered trademark of Texas Instruments.
2
Windows is a registered trademark of Microsoft Corporation.
3
All other trademarks are the property of their respective owners.
4
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2004–2005, Texas Instruments Incorporated