SIMPLE SWITCHER® 8V to 40V, 3A Low Component Count Step-Down Regulator

The LM2676 series of regulators are monolithic integrated circuits which provide all of the active functions for a step-down (buck) switching regulator capable of driving up to 3A loads with excellent line and load regulation characteristics. High efficiency (> 90%) is obtained through the use of a low ON-resistance DMOS power switch. The series consists of fixed output voltages of 3.3V, 5V, and 12V and an adjustable output version.

The SIMPLE SWITCHER power converter concept provides for a complete design using a minimum number of external components. A high fixed frequency oscillator (260kHz) allows the use of physically smaller sized components. A family of standard inductors for use with the LM2676 are available from several manufacturers to greatly simplify the design process.

The LM2676 series also has built-in thermal shutdown, current limiting, and an ON and OFF control input that can power down the regulator to a low 50µA quiescent current standby condition. The output voltage is specified to a ±2% tolerance. The clock frequency is controlled to within a ±11% tolerance.