LM2673 Datasheet | National Semiconductor

Description The LM2673 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 concept provides for a plete design using a minimum number of external ponents. A high fixed frequency oscillator (260KHz) allows the use of physically smaller sized ponents. A family of standard inductors for use with the LM2673 are available from several manufacturers to greatly simplify the design process. Other features include the ability to reduce the input surge current at power-ON by adding a softstart timing capacitor to gradually turn on the regulator. The LM2673 series also has built in thermal shutdown and resistor programmable current limit of the power MOSFET switch to protect the device and load circuitry under fault conditions. The output voltage is guaranteed to a ± 2% tolerance. The clock frequency is controlled to within a ± 11% tolerance. Features n Efficiency up to 94% n Simple and easy to design with (using off-the-shelf external ponents) n Resistor programmable peak current limit over a range of 2A to 5A. n 150 mΩ DMOS output switch n 3.3V, 5V and 12V fixed output and adjustable (1.2V to 37V ) versions n ± 2%maximum output tolerance over full line and load conditions n Wide input voltage range: 8V to 40V n 260 KHz fixed frequency internal oscillator n Softstart capability n - 40 to +125˚C operating junction temperature range Applications n Simple to design, high efficiency ( > 90%) step-down switching regulators n Efficient system pre-regulator for linear voltage regulators n Battery chargers Typical Application DS100913-3 SIMPLE SWITCHER ® is a registered trademark of National...