LM73605

ACTIVE

3.5V to 36V, 5A Synchronous Step-Down Voltage Converter

A newer version of this product is available

open-in-new Compare alternates
Same functionality with different pin-out to the compared device
LM61460 ACTIVE 3-V to 36-V, 6-A, Low-EMI synchronous step-down converter Smaller solution size, higher efficiency and lower EMI.
TPSM63608 ACTIVE High-density, 36-V input, 1-V to 20-V output, 6-A power module in 7.5-mm x 6.5-mm HotRod™ QFN Smaller design with an integrated-inductor power module.

Product details

Rating Catalog Operating temperature range (°C) -40 to 125 Topology Buck Type Converter Iout (max) (A) 5 Vin (min) (V) 3.5 Vin (max) (V) 36 Switching frequency (min) (kHz) 350 Switching frequency (max) (kHz) 2200 Features Enable, Forced PWM, Frequency synchronization, Light Load Efficiency, Over Current Protection, Power good, Pre-Bias Start-Up, Soft Start Adjustable, Synchronous Rectification, Tracking, UVLO Fixed, Wettable flanks package Control mode current mode Vout (min) (V) 1 Vout (max) (V) 34 Iq (typ) (µA) 15 Duty cycle (max) (%) 96
Rating Catalog Operating temperature range (°C) -40 to 125 Topology Buck Type Converter Iout (max) (A) 5 Vin (min) (V) 3.5 Vin (max) (V) 36 Switching frequency (min) (kHz) 350 Switching frequency (max) (kHz) 2200 Features Enable, Forced PWM, Frequency synchronization, Light Load Efficiency, Over Current Protection, Power good, Pre-Bias Start-Up, Soft Start Adjustable, Synchronous Rectification, Tracking, UVLO Fixed, Wettable flanks package Control mode current mode Vout (min) (V) 1 Vout (max) (V) 34 Iq (typ) (µA) 15 Duty cycle (max) (%) 96
WQFN (RNP) 30 24 mm² 6 x 4
  • New product available: LM61460 60-V, 6-A synchronous converter
  • Synchronous rectification
  • Wettable flanks QFN package (WQFN)
  • Low quiescent current
    • 0.8 µA in shutdown (typical)
    • 15 µA in active mode with no load (typical)
  • Wide voltage conversion range:
    • tON-MIN = 60 ns (typical)
    • tOFF-MIN = 70 ns (typical)
  • Low MOSFET ON-resistance:
    • RDS_ON_HS = 53 mΩ (typical)
    • RDS_ON_LS = 31 mΩ (typical)
  • External bias input to improve efficiency
  • Pin-selectable auto mode or forced PWM operation
  • Adjustable frequency range: 350 kHz to 2.2 MHz
  • Synchronizable to external clock
  • Internal compensation
  • Power-good flag
  • Precision enable to program system UVLO
  • Flexible soft-start features:
    • Start-up into pre-biased load
    • Fixed or adjustable soft-start time
    • Output voltage tracking
  • Cycle-by-cycle current limiting
  • Short-circuit protection with hiccup mode
  • Create a custom design with the WEBENCH® power designer using LM73605 or LM73606
  • New product available: LM61460 60-V, 6-A synchronous converter
  • Synchronous rectification
  • Wettable flanks QFN package (WQFN)
  • Low quiescent current
    • 0.8 µA in shutdown (typical)
    • 15 µA in active mode with no load (typical)
  • Wide voltage conversion range:
    • tON-MIN = 60 ns (typical)
    • tOFF-MIN = 70 ns (typical)
  • Low MOSFET ON-resistance:
    • RDS_ON_HS = 53 mΩ (typical)
    • RDS_ON_LS = 31 mΩ (typical)
  • External bias input to improve efficiency
  • Pin-selectable auto mode or forced PWM operation
  • Adjustable frequency range: 350 kHz to 2.2 MHz
  • Synchronizable to external clock
  • Internal compensation
  • Power-good flag
  • Precision enable to program system UVLO
  • Flexible soft-start features:
    • Start-up into pre-biased load
    • Fixed or adjustable soft-start time
    • Output voltage tracking
  • Cycle-by-cycle current limiting
  • Short-circuit protection with hiccup mode
  • Create a custom design with the WEBENCH® power designer using LM73605 or LM73606

The LM73605 and LM73606 family of devices are easy-to-use synchronous step-down DC/DC converters capable of driving up to 5 A or 6 A of load current from a supply voltage ranging from 3.5 V to 36 V. The LM73605 and LM73606 provide exceptional efficiency and output accuracy in a very small solution size. Peak current-mode control is employed. Additional features such as adjustable switching frequency, synchronization to an external clock, power-good flag, precision enable, adjustable soft start, and tracking provide both flexible and easy-to-use solutions for a wide range of applications. Automatic frequency foldback at light load improves efficiency over the entire load range. Protection features include thermal shutdown, cycle-by-cycle current limiting, and short-circuit protection. The devices are pin-to-pin compatible for easy current scaling. The new product, LM61460-Q1, offers higher efficiency, lower stand-by quiescent current, and improved EMI performance. See the device comparison table to compare specifications. Start a Webench design with LM61460-Q1. Use the LMZM33606 module for faster time to market.

The LM73605 and LM73606 family of devices are easy-to-use synchronous step-down DC/DC converters capable of driving up to 5 A or 6 A of load current from a supply voltage ranging from 3.5 V to 36 V. The LM73605 and LM73606 provide exceptional efficiency and output accuracy in a very small solution size. Peak current-mode control is employed. Additional features such as adjustable switching frequency, synchronization to an external clock, power-good flag, precision enable, adjustable soft start, and tracking provide both flexible and easy-to-use solutions for a wide range of applications. Automatic frequency foldback at light load improves efficiency over the entire load range. Protection features include thermal shutdown, cycle-by-cycle current limiting, and short-circuit protection. The devices are pin-to-pin compatible for easy current scaling. The new product, LM61460-Q1, offers higher efficiency, lower stand-by quiescent current, and improved EMI performance. See the device comparison table to compare specifications. Start a Webench design with LM61460-Q1. Use the LMZM33606 module for faster time to market.

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Technical documentation

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Type Title Date
* Data sheet LM73605/LM73606 3.5-V to 36-V, 5-A or 6-A Synchronous Step-Down Voltage Converter datasheet (Rev. A) PDF | HTML 21 Jul 2017
Functional safety information LM73605 Functional Safety, FIT Rate, Failure Mode Distribution and Pin FMA PDF | HTML 12 Jul 2022
Application note Step-Dwn (Buck) Convrtr Pwer Solutions for Programmable Logic Controller Systems (Rev. A) PDF | HTML 26 Jul 2021
Selection guide Buck Converter Quick Reference Guide (Rev. B) 08 Apr 2021
Technical article How to add hysteresis to a DC/DC converter PDF | HTML 12 Nov 2018
Technical article Effects of IC package on EMI performance PDF | HTML 22 May 2018
Technical article Vary the output voltage in an inverting buck-boost topology PDF | HTML 12 Oct 2017
Application note Designing High Performance, Low-EMI, Automotive Power Supplies 30 Sep 2017
EVM User's guide LM73605/LM73606 EVM User's Guide 20 Sep 2017

Design & development

For additional terms or required resources, click any title below to view the detail page where available.

Evaluation board

LM73605EVM-5V-2MHZ — LM73605 Synchronous Step-Down Converter Evaluation Module

The LM73605EVM-5V-2MHZ evaluation module (EVM) is a fully assembled and tested circuit for evaluating the LM73605 synchronous step-down voltage converter. The EVM operates from 6V to 36V input and provides a 5V output voltage with 5A maximum load current.
User guide: PDF
Not available on TI.com
Evaluation board

LM73605EVM-5V-400K — LM73605 Synchronous Step-Down Converter Evaluation Module

The LM73605EVM-5V-400K evaluation module (EVM) is a fully assembled and tested circuit for evaluating the LM73605 synchronous step-down voltage converter. The EVM operates from 6V to 36V input and provides a 5V output voltage with 5A maximum load current.

User guide: PDF
Not available on TI.com
Simulation model

LM73605 Inverting and non-inverting PSpice Transient Model

SNVMBD7.ZIP (955 KB) - PSpice Model
Simulation model

LM73605 TINA-TI Transient Reference Design

SNVMBE0.TSC (2316 KB) - TINA-TI Reference Design
Simulation model

LM73605 TINA-TI Transient Spice Model

SNVMBE1.ZIP (79 KB) - TINA-TI Spice Model
Simulation model

LM73605 Unencrypted PSpice Transient Model

SNVJ003.ZIP (9 KB) - Spice Model
Simulation model

TINA-TI Enable Hysteresis Schematic

SNVMBL7.ZIP (4 KB) - TINA-TI Reference Design
Calculation tool

SNVR524 LM73605 Quickstart Tool

Supported products & hardware

Supported products & hardware

Products
AC/DC & DC/DC converters (integrated FET)
LM73605 3.5V to 36V, 5A Synchronous Step-Down Voltage Converter LM73605-Q1 Automotive qualified 3.5-V to 36-V, 5-A synchronous step-down voltage converter LM73606 3.5V to 36V, 6A Synchronous Step-Down Voltage Converter LM73606-Q1 Automotive qualified 3.5-V to 36-V, 6-A synchronous step-down voltage converter
Reference designs

TIDA-01458 — Low-Noise Fixed Drop-Out ±2.5 to ±12-VOUT 3A Power Supply Reference Design for Ultrasound CW Pulser

This reference design allows a digitally programmable power supply to power an ultrasound transmit circuit for continuous wave (CW) mode from a 24-V bus. There are two outputs adjustable from ±2.5 to ±12 V under user software control. These outputs can provide up to 2 A with very low (...)
Design guide: PDF
Schematic: PDF
Reference designs

TIDA-010011 — High efficiency power supply architecture reference design for protection relay processor module

This reference design showcases various power architectures for generating multiple voltage rails for an application processor module, requiring >1A load current and high efficiency . The required power supply is generated using 5-, 12- or 24-V DC input from the backplane. Power supplies are (...)
Design guide: PDF
Schematic: PDF
Package Pins CAD symbols, footprints & 3D models
WQFN (RNP) 30 Ultra Librarian

Ordering & quality

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  • Ongoing reliability monitoring
Information included:
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