參數(shù)資料
型號: LM2676
文件頁數(shù): 1/25頁
文件大小: 495K
代理商: LM2676
LM2671
SIMPLE SWITCHER
Power Converter High Efficiency
500mA Step-Down Voltage Regulator with Features
General Description
The LM2671 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 500mA 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), fixed frequency oscillator, external shutdown,
soft-start, and frequency synchronization.
The LM2671 series operates at a switching frequency of
260 kHz, thus allowing smaller sized filter components than
what would be needed with lower frequency switching regu-
lators. Because of its very high efficiency (
>
90%), the cop-
per traces on the printed circuit board are the only heat
sinking needed.
A family of standard inductors for use with the LM2671 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. Ex-
ternal 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 LM2671 buck regulator design procedure,
there exists computer design software,
LM267X Made
Simple
(version 6.0).
Features
n
Efficiency up to 96%
n
Available in SO-8, 8-pin DIP and LLP packages
n
Computer Design Software
LM267X Made Simple
(version 6.0)
n
Simple and easy to design with
n
Requires only 5 external components
n
Uses readily available standard inductors
n
3.3V, 5.0V, 12V, and adjustable output versions
n
Adjustable version output voltage range: 1.21V to 37V
n
±
1.5% max output voltage tolerance over line and load
conditions
n
Guaranteed 500mA output load current
n
0.25
DMOS Output Switch
n
Wide input voltage range: 8V to 40V
n
260 kHz fixed frequency internal oscillator
n
TTL shutdown capability, low power standby mode
n
Soft-start and frequency synchronization
n
Thermal shutdown and current limit protection
Applications
n
Simple High Efficiency (
>
90%) Step-Down (Buck)
Regulator
n
Efficient Pre-Regulator for Linear Regulators
Typical Application
(Fixed Output Voltage Versions)
10004201
SIMPLE SWITCHER
is a registered trademark of National Semiconductor Corporation.
Windows
is a registered trademark of Microsoft Corporation.
May 2001
L
R
2001 National Semiconductor Corporation
DS100042
www.national.com
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
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LM2676LD-ADJ 制造商:Rochester Electronics LLC 功能描述:3A STEP DOWN SIMP SWITCH 260KH - Bulk 制造商:Texas Instruments 功能描述:
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