Features and Benefits

  • Flexible Power Supply System Capable of Four Regulated Outputs with VBATT << VOUT
  • Two High Voltage Synchronous Buck Regulators
    • 3V to 42V Input Voltage Range
    • Output Currents Up to 2.5A and 1.5A
  • One Low Voltage Synchronous Buck Regulator
    • 2.6V to 5.5V Input Voltage Range
    • Output Currents Up to 1.8A
  • One Boost Controller Allows Buck Converters to Regulate with VBATT << VOUT
  • Selectable Burst Mode® Operation Allows Low 28µA IQ with High Voltage Channels Active
  • Programmable Power-On Reset
  • Individual Channel Power Good Indicators
  • Step-Down Switching Frequency: 250kHz to 2.2MHz
  • Available in 40-Lead QFN (6mm × 6mm) Package
  • AEC-Q100 Qualified for Automotive Applications

Product Details

The LT®8603 is a highly flexible, quad output regulator combining two high input voltage capable monolithic step-down switching regulators, one low input voltage capable monolithic step-down regulator, and a boost controller to satisfy a wide range of applications while occupying minimal board space.

With the boost controller configured to supply the chip VIN supply, the LT8603 produces three precisely regulated outputs even when the boost input voltage falls significantly below the regulated output voltages, such as during an automotive cold crank scenario. Alternatively, with the boost controller driven from one of the step-down regulator outputs or configured as a SEPIC, the LT8603 provides four precisely regulated outputs over a wide input voltage range.

The LT8603 provides robust regulation by including a cycle-by-cycle current limit for all step-down regulators, thermal shutdown, and a boost controller that can tolerate reverse battery connections and negative transient input voltages down to –42V.


  • Automotive Stop-Start and Cold Crank Ride Through
  • Last-Gasp CPU Power Hold-Up
  • Industrial Controls and Power Supplies

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.

Evaluation Kits (2)

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:


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

The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.

Selecting the Sample button above will redirect to the third-party ADI Sample Site. The part selected will carry over to your cart on this site once logged in. Please create a new account there if you have never used the site before. Contact SampleSupport@analog.com with any questions regarding this Sample Site.

Price Table Help


Evaluation Boards

Pricing displayed is based on 1-piece.

Up to two boards can be purchased through Analog.com. To order more than two, please purchase through one of our listed distributors.

Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.