LM2671N-ADJ

Output Power :
Input Voltage :
Operating Temperature Range :
Packaging : Tube
Switching Frequency : 260 KHz
Mounting Style : Through Hole
Package / Case : PDIP-8
Output Current : 0.5 A
Output Voltage : 1.21 V to 37 V


Features:

`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
`0.25 DMOS Output Switch
`Wide input voltage range:8V to 40V
`260 kHz fixed frequency internal oscillator
`TTL shutdown capability,low power standby mode
`Soft-start and frequency synchronization
`Thermal shutdown and current limit protection


Application

·Simple High Efficiency ( > 90%) Step-Down (Buck)  Regulator
·Efficient Pre-Regulator for Linear Regulators


Specifications

Supply Voltage................45V
ON/OFF Pin Voltage..............-0.1V VSH 6V
Switch Voltage to Ground...........-1V
Boost Pin Voltage...............VSW+8V
Feedback Pin Voltage............. -0.3V VFB 14V
ESD Susceptibility
Human Body Model (Note2)..........2kV
Power Dissipation...............Internally  Limited
Operating Ratings
Supply Voltage.................6.5V to 40V
Storage Temperature Range..........-65 to+150
LeadTemperature
M Package
   Vapor Phase(60s)...............+215
   Infrared(15s) .................+220
N Package (Soldering,10s)  ...........+260
LLP Package(See AN-1187)
Maximum Junction Temperature.........+150
Temperature Range...........-40 TJ+125 


Description

The LM2671N-ADJ series of regulators are monolithic integrated circuits built with a LMDMOS process.These regulators provide all the active functions for astep-down (buck) switchin regulator,capable of driving a 1A load current with excellent line and load regulation.These devices are avail- able 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 LM2671N-ADJ series operates at a switching frequency of 260 kHz,thus allowing smaller sizedfilter components than what would be needed with lower frequency switching regu-
lators.Because of its very high efficiency (>90%),the cop- pe rtraces on the printed circuit board are the only heat sinking needed.

A family of standard inductors for use with the LM2671N-ADJ are available from severa ldifferent 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 workin switch-mode power supplies.

Other features include a guaranteed ±1.5%tolerance on output voltage within specified input voltages and output 10%on the oscillator frequency.Ex- ternal shutdown is included,featuring typically 50 A stand-by current.The output switch includes current limiting, as well as thermal shutdown for fullprotection under fault conditions.

To simplify the LM2671N-ADJ buck regulator design procedure, there exists computer design software, LM267X Made Simple (version 6.0).