Output Power
:
Input Voltage
:
Operating Temperature Range
:
Packaging
: Tube
Output Current
: 1 A
Switching Frequency
: 260 KHz
Mounting Style
: Through Hole
Package / Case
: PDIP-8
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
·Thermal shutdown and current limit protectionApplication·Simple High Efficiency ( > 90%) Step-Down (Buck) Regulator
·Efficient Pre-Regulator for Linear Regulators
·Positive-to-Negative ConverterSpecificationsSupply Voltage................45V
ON/OFFPinVoltage..............-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 to40V
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
Junction Temperature Range...........-40 TJ+125DescriptionThe LM2675N-ADJ series of regulators are monolithi cintegrated 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 LM2675N-ADJ series operates at a switching frequency of 260kHz,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 LM2675 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 LM2675 buck regulator design procedure, there exists computer design software, LM267X Made Simple version 6.0.
LM2675N-ADJ Data Sheet
