The LM2675N-ADJ 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 LM2675N-ADJ 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.
A family of standard inductors for use with the LM2675N-ADJ 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 standby current. The output switch includes current limiting, as well as thermal shutdown for full protection under fault conditions.
Feature
- 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
