LM2678 Datasheet, PDF (1/36 Pages) National Semiconductor (TI) – SIMPLE SWITCHER High Efficiency 5A Step-Down Voltage Regulator

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LM2678
SNVS029J – MARCH 2000 – REVISED JULY 2016
LM2678 SIMPLE SWITCHER^® High Efficiency 5-A Step-Down Voltage Regulator
1 Features
•1 Efficiency Up to 92%
• Simple and Easy to Design Using Off-the-Shelf
External Components
• 120-mΩ DMOS Output Switch
• 3.3-V, 5-V, and 12-V Fixed Output and Adjustable
(1.2 V to 37 V) Versions
• 50-μA Standby Current When Switched OFF
• ±2% Maximum Output Tolerance Over Full Line
and Load Conditions
• Wide Input Voltage Range: 8 V to 40 V
• 260-kHz Fixed Frequency Internal Oscillator
• −40 to 125°C Operating Junction Temperature
Range
2 Applications
• Simple-to-Design, High Efficiency (>90%) Step-
Down Switching Regulators
• Efficient System Preregulator for Linear Voltage
Regulators
• Battery Chargers
3 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 5-A 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 3.3 V, 5 V, and 12 V 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
(260 kHz) 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 50-
μA quiescent current standby condition. The output
voltage is ensured to a ±2% tolerance. The clock
frequency is controlled to within a ±11% tolerance.
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (NOM)
TO-263 (7)
10.10 mm × 8.89 mm
LM2678
TO-220 (7)
14.986 mm × 10.16 mm
VSON (14)
6.00 mm × 5.00 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
Typical Application
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.