LM2678S-ADJ Datasheet, PDF (1/35 Pages) Texas Instruments – LM2678 SIMPLE SWITCHER High Efficiency 5A Step-Down Voltage Regulator

LM2678
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SNVS029I – MARCH 2000 – REVISED APRIL 2013
LM2678 SIMPLE SWITCHER^® High Efficiency 5A Step-Down Voltage Regulator
Check for Samples: LM2678
FEATURES
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•23 Efficiency Up to 92%
• Simple and Easy to Design with (Using Off-
The-Shelf External Components)
• 120 mΩ DMOS Output Switch
• 3.3V, 5V and 12V Fixed Output and Adjustable
(1.2V to 37V ) Versions
• 50μA Standby Current When Switched OFF
• ±2% Maximum Output Tolerance Over Full
Line and Load Conditions
• Wide Input Voltage Range: 8V to 40V
• 260 KHz Fixed Frequency Internal Oscillator
• −40 to +125°C Operating Junction Temperature
Range
APPLICATIONS
• Simple to Design, High Efficiency (>90%) Step-
Down Switching Regulators
• Efficient System Pre-Regulator for Linear
Voltage Regulators
• Battery Chargers
DESCRIPTION
The LM2678 series of regulators are monolithic
integrated circuits which provide all of the active
functions for a step-down (buck) switching regulator
capable of driving up to 5A loads with excellent line
and load regulation characteristics. High efficiency
(>90%) is obtained through the use of a low ON-
resistance DMOS power switch. The series consists
of fixed output voltages of 3.3V, 5V and 12V and an
adjustable output version.
The SIMPLE SWITCHER^® concept provides for a
complete design using a minimum number of external
components. A high fixed frequency oscillator
(260KHz) allows the use of physically smaller sized
components. A family of standard inductors for use
with the LM2678 are available from several
manufacturers to greatly simplify the design process.
The LM2678 series also has built in thermal
shutdown, current limiting and an ON/OFF control
input that can power down the regulator to a low
50μA quiescent current standby condition. The output
voltage is ensured to a ±2% tolerance. The clock
frequency is controlled to within a ±11% tolerance.
Typical Application
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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, Switchers Made Simple are registered trademarks of Texas Instruments.
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All other trademarks are the property of their respective owners.
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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 © 2000–2013, Texas Instruments Incorporated