|
|
Número de pieza | LM2674M-ADJ | |
Descripción | SIMPLE SWITCHER Power Converter High Efficiency 500 mA Step-Down Voltage Regulator | |
Fabricantes | National Semiconductor | |
Logotipo | ||
Hay una vista previa y un enlace de descarga de LM2674M-ADJ (archivo pdf) en la parte inferior de esta página. Total 22 Páginas | ||
No Preview Available ! September 1998
LM2674
SIMPLE SWITCHER® Power Converter High Efficiency
500 mA Step-Down Voltage Regulator
General Description
The LM2674 series of regulators are monolithic integrated
circuits built with a LMDMOS process. These regulators pro-
vide all the active functions for a step-down (buck) switching
regulator, capable of driving a 500 mA load current with ex-
cellent 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 LM2674 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 sink-
ing needed.
A family of standard inductors for use with the LM2674 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 LM2674 buck regulator design procedure,
there exists computer design software, LM267X Made
Simple.
Features
n Efficiency up to 96%
n Available in SO-8 and 8-pin DIP packages
n Computer Design Software LM267X Made Simple
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 0.25Ω 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 Thermal shutdown and current limit protection
Typical Applications
n Simple High Efficiency (>90%) Step-Down (Buck)
Regulator
n Efficient Pre-Regulator for Linear Regulators
n Positive-to-Negative Converter
Typical Application
SIMPLE SWITCHER® is a registered trademark of National Semiconductor Corporation.
Windows® is a registered trademark of Microsoft Corporation.
© 1999 National Semiconductor Corporation DS100041
DS100041-1
www.national.com
1 page Typical Performance Characteristics (Continued)
Standby
Quiescent Current
ON/OFF Threshold
Voltage
ON/OFF Pin
Current (Sourcing)
DS100041-9
Switching Frequency
Feedback Pin
Bias Current
DS100041-10
DS100041-11
Peak Switch Current
DS100041-12
Dropout Voltage — 3.3V Option
DS100041-13
Dropout Voltage — 5.0V Option
DS100041-14
DS100041-15
DS100041-16
5 www.national.com
5 Page LM2674 Series Buck Regulator Design Procedure (Fixed Output) (Continued)
INDUCTOR VALUE SELECTION GUIDES (For Continuous Mode Operation)
DS100041-26
FIGURE 4. LM2674-3.3
FIGURE 6. LM2674-12
DS100041-28
DS100041-27
FIGURE 5. LM2674-5.0
FIGURE 7. LM2674-ADJ
DS100041-29
11 www.national.com
11 Page |
Páginas | Total 22 Páginas | |
PDF Descargar | [ Datasheet LM2674M-ADJ.PDF ] |
Número de pieza | Descripción | Fabricantes |
LM2674M-ADJ | SIMPLE SWITCHER Power Converter High Efficiency 500 mA Step-Down Voltage Regulator | National Semiconductor |
Número de pieza | Descripción | Fabricantes |
SLA6805M | High Voltage 3 phase Motor Driver IC. |
Sanken |
SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
Analog Devices |
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |