Features and Benefits

  • Low Resistance Pass Transistor: 0.25Ω
  • Dropout Voltage: 0.75V at 3A
  • ±1% Reference Voltage
  • Accurate Programmable Current Limit
  • Shutdown Capability
  • Internal Reference Available
  • Full Remote Sense
  • Low Quiescent Current: 2.5mA
  • Good High Frequency Ripple Rejection
  • Available in 5-Lead TO-220 and DD Packages

Product Details

The LT1185 is a 3A low dropout regulator with adjustable current limit and remote sense capability. It can be used as a positive output regulator with floating input or as a standard negative regulator with grounded input. The output voltage range is 2.5V to 25V, with ±1% accuracy on the internal reference voltage.

The LT1185 uses a saturation-limited NPN transistor as the pass element. This device gives the linear dropout characteristics of a FET pass element with significantly less die area. High efficiency is maintained by using special anti-saturation circuitry that adjusts base drive to track load current. The “on resistance” is typically 0.25Ω.

Accurate current limit is programmed with a single 1/8W external resistor, with a range of zero to three amperes. A second, fixed internal limit circuit prevents destructive currents if the programming current is accidentally over-ranged. Shutdown of the regulator output is guaranteed when the program current is less than 1µA, allowing external logic control of output voltage.

The LT1185 has all the protection features of our previous regulators, including power limiting and thermal shutdown.

Product Lifecycle icon-recommended Production

At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.

Tools & Simulations


LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.

To launch ready-to-run LTspice demonstration circuits for this part:

Step 1: Download and install LTspice on your computer.

Step 2: Click on the link in the section below to download a demonstration circuit.

Step 3: If LTspice does not automatically open after clicking the link below, you can instead run the simulation by right clicking on the link and selecting “Save Target As.” After saving the file to your computer, start LTspice and open the demonstration circuit by selecting ‘Open’ from the ‘File’ menu.


Models for the following parts are available in LTspice:


Product Recommendations

LT1185 Companion Parts

Recommended Related Parts

Design Resources

ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well.  "Zero defects" for shipped products is always our goal.

Sample & Buy

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