LM2675 SIMPLE SWITCHER® Power Converter High Efficiency 1-A Step-Down Voltage Regulator
1 Features
- Efficiency up to 96%
- Available in 8-Pin SOIC, PDIP, and 16-Pin WSON Package
- Requires only 5 External Components
- 3.3-V, 5-V, 12-V, and Adjustable Output Versions
- Adjustable Version Output Voltage Range: 1.21 V to 37 V
- ±1.5% Maximum Output Voltage Tolerance Over Line and Load Conditions
- Ensured 1-A Output Load Current
- Wide Input Voltage Range: 8 V to 40 V
- 260-kHz Fixed Frequency Internal Oscillator
- TTL Shutdown Capability, Low-Power Standby Mode
- Thermal Shutdown and Current Limit Protection
2 Applications
- Simple High Efficiency (>90%) Step-Down (Buck) Regulator
- Efficient Preregulator for Linear Regulators
- Positive-to-Negative Converter
3 Description
The LM2675 series of regulators are monolithic integrated DC-DC converter circuits built with a LMDMOS process. These regulators provide all the active functions for a step-down (buck) switching regulator, capable of driving a 1-A load current with excellent line and load regulation. These devices are available in fixed output voltages of 3.3 V, 5 V, 12 V, and an adjustable output version.
Requiring a minimum number of external components, these regulators are simple to use and include patented internal frequency compensation and a fixed frequency oscillator.
The LM2675 series operates at a switching frequency of 260 kHz, thus allowing smaller-sized filter components than what would be needed with lower frequency switching regulators. Because of its very high efficiency (>90%), the copper traces on the printed-circuit board are the only heat sinking needed.
Device Information(1)
| PART NUMBER | PACKAGE | BODY SIZE (NOM) |
|---|---|---|
| LM2675 | SOIC (8) | 5.00 mm × 6.20 mm |
| PDIP (8) | 10.16 mm × 6.60 mm | |
| WSON (16) | 5.00 mm × 5.00 mm |
- For all available packages, see the orderable addendum at the end of the data sheet.
Typical Application
4 Revision History
Changes from E Revision (June 2005) to F Revision
- Added ESD Ratings table, Feature Description section, Device Functional Modes, Application and Implementation section, Power Supply Recommendations section, Layout section, Device and Documentation Support section, and Mechanical, Packaging, and Orderable Information sectionGo
- Deleted all instances of the computer design software LM267X Made Simple (version 6.0)Go
5 Description (continued)
A family of standard inductors for use with the LM2675 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 data sheet are selector guides for diodes and capacitors designed to work in switch-mode power supplies.
Other features include ±1.5%-tolerance on output voltage within specified input voltages and output load conditions, and ±10% on the oscillator frequency. External 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.
