20-A automotive pre-regulator reference design
This product has been released to the market and is available for purchase. For some products, newer alternatives may be available.

Description & Features

Technical documentation

Support & Training

Order Now

See the Important Notice and Disclaimer covering reference designs and other TI resources.

Key Document


This reference design is a 100-W synchronous buck converter to supply automotive loads. The IC is LM5146-Q1 in fixed frequency operation at 250 kHz to ensure low noise operation. A resistor-capacitor (RC) snubber attenuates noise in the RF band to reduce radiated emissions. To reduce system EMI, the design is prepared to either synchronize other converters (output) or be externally synchronized (input).

  • Power stage withstands surge voltages up to 36 Vpk
  • Efficiency higher than 95% over a output current range of 5-A to 20-A  (at 14-V input voltage)
  • Tight load regulation results in a low deviation (5 mV) of the output voltage over the whole range of the input voltage
  • Input filter for minimizing conducted emissions is included

See the Important Notice and Disclaimer covering reference designs and other TI resources.


Schematic/Block Diagram

Quickly understand overall system functionality.

Download Schematic

Design Guide

Get results faster with test and simulation data that's been verified.

Download Design Guide

Design Files

Download ready-to-use system files to speed your design process. Get Viewer.

Download Design Files

(Output Voltage 1)
Vin (Min) (V)6
Vin (Max) (V)18
Vout (Nom) (V)5
Iout (Max) (A)20
Output Power (W)100
Input TypeDC
TopologyBuck- Synchronous

TI Devices (1)

Order samples, get tools and find more information on the TI products in this reference design.

Part Number Name Product Family Sample & Buy Design Kits & Evaluation Modules
LM5146-Q1  Automotive 100-V synchronous buck DC/DC controller with wide duty-cycle range  Step-down (buck) regulators  Sample & Buy View Design Kits & Evaluation Modules

CAD/CAE symbols

Part # Package | Pins CAD File (.bxl) STEP Model (.stp)
LM5146-Q1 Download Download

Texas Instruments and Accelerated Designs, Inc. have collaborated together to provide TI customers with schematic symbols and PCB layout footprints for TI products.

Step 1: Download and install the free download.

Step 2: Download the Symbol and Footprint from the CAD.bxl file table.

Technical documentation

See the Important Notice and Disclaimer covering reference designs and other TI resources.

User guide (1)
Title Type Size (KB) Date
PDF 1999 13 Aug 2019
Design files (6)
Title Type Size (KB) Date
ZIP 62 13 Aug 2019
ZIP 561 13 Aug 2019
PDF 862 13 Aug 2019
PDF 105 13 Aug 2019
PDF 137 13 Aug 2019
PDF 114 13 Aug 2019
Related Tools & Software

Reference Designs (3)

Support & training

TI E2E™ forums with technical support from TI engineers

Search our extensive online knowledge base where millions of technical questions and answers are available 24/7.

Search answers from TI experts

Content is provided 'AS IS' by the respective TI and Community contributors and does not constitute TI specifications.
See terms of use.

If you have questions about quality, packaging, or ordering TI products visit our Support page.

Technical articles