3A Step-Down Voltage Regulator with Adjustable Current Limit - LM2673


3A Step-Down Voltage Regulator with Adjustable Current Limit


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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 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 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 ensured to a ±2% tolerance. The clock frequency is controlled to within a ±11% tolerance.


  • Efficiency Up to 94%
  • Simple and Easy to Design with (Using Off-The-Shelf External Components)
  • Resistor Programmable Peak Current Limit Over a Range of 2A to 5A
  • 150 mΩ DMOS Output Switch
  • 3.3V, 5V and 12V Fixed Output and Adjustable (1.2V to 37V) Versions
  • ±2% Maximum Output Tolerance Over Full Line and Load Conditions
  • Wide Input Voltage Range: 8V to 40V
  • 260 KHz Fixed Frequency Internal Oscillator
  • Softstart Capability
  • −40 to +125°C Operating Junction Temperature Range

SIMPLE SWITCHER is a trademark of Texas Instruments. All trademarks are the property of their respective owners. SIMPLE SWITCHER is a trademark of Texas Instruments. Switchers Made Simple is a trademark of Texas Instruments.

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Parametrics Compare all products in Buck Converter (Integrated Switch)

Vin (Min) (V)
Vin (Max) (V)
Vout (Min) (V)
Vout (Max) (V)
Iout (Max) (A)
Regulated Outputs (#)
Switching Frequency (Min) (kHz)
Switching Frequency (Max) (kHz)
Iq (Typ) (mA)
Special Features
Control Mode
Duty Cycle (Max) (%)
Operating Temperature Range (C)
Package Group
Approx. Price (US$)
Voltage Mode    
-40 to 125    
1.85 | 1ku    

Related end equipment

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WEBENCH® Designer LM2673

  Min   Max Range
Vin  V 8.0 to 40.0V
Vout  V 1.21 to 40.0V
Iout  A ≤ 3A
Ambient Temp  °C -40 to 125°C

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