LM43601

ACTIVE

3.5V to 36V, 1A Synchronous Step-Down Voltage Converter

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LMR33610 ACTIVE SIMPLE SWITCHER® 3.8-V to 36-V, 1-A synchronous step-down converter in SOIC-8 package Smaller footprint, higher efficiency, lower IQ and lower EMI.

Product details

Rating Catalog Operating temperature range (°C) -40 to 125 Topology Buck Type Converter Iout (max) (A) 1 Vin (min) (V) 3.5 Vin (max) (V) 36 Switching frequency (min) (kHz) 200 Switching frequency (max) (kHz) 2200 Features Enable, Frequency synchronization, Light Load Efficiency, Over Current Protection, Power good, Pre-Bias Start-Up, Synchronous Rectification, Tracking Control mode current mode Vout (min) (V) 1 Vout (max) (V) 28 Iq (typ) (µA) 33 Duty cycle (max) (%) 99
Rating Catalog Operating temperature range (°C) -40 to 125 Topology Buck Type Converter Iout (max) (A) 1 Vin (min) (V) 3.5 Vin (max) (V) 36 Switching frequency (min) (kHz) 200 Switching frequency (max) (kHz) 2200 Features Enable, Frequency synchronization, Light Load Efficiency, Over Current Protection, Power good, Pre-Bias Start-Up, Synchronous Rectification, Tracking Control mode current mode Vout (min) (V) 1 Vout (max) (V) 28 Iq (typ) (µA) 33 Duty cycle (max) (%) 99
HTSSOP (PWP) 16 32 mm² 5 x 6.4
  • 33-µA Quiescent Current in Regulation
  • High Efficiency at Light Load (DCM and PFM)
  • Meets EN55022/CISPR 22 EMI Standards
  • Integrated Synchronous Rectification
  • Adjustable Frequency Range: 200 kHz to 2.2 MHz (500 kHz default)
  • Frequency Synchronization to External Clock
  • Internal Compensation
  • Stable With Almost Any Combination of Ceramic, Polymer, Tantalum, and Aluminum Capacitors
  • Power-Good Flag
  • Soft Start into Pre-Biased Load
  • Internal Soft Start: 4.1 ms
  • Extendable Soft-Start Time by External Capacitor
  • Output Voltage Tracking Capability
  • Precision Enable to Program System UVLO
  • Output Short-Circuit Protection With Hiccup Mode
  • Overtemperature Thermal Shutdown Protection
  • Create a Custom Design Using the LM43601 With the WEBENCH® Power Designer
  • 33-µA Quiescent Current in Regulation
  • High Efficiency at Light Load (DCM and PFM)
  • Meets EN55022/CISPR 22 EMI Standards
  • Integrated Synchronous Rectification
  • Adjustable Frequency Range: 200 kHz to 2.2 MHz (500 kHz default)
  • Frequency Synchronization to External Clock
  • Internal Compensation
  • Stable With Almost Any Combination of Ceramic, Polymer, Tantalum, and Aluminum Capacitors
  • Power-Good Flag
  • Soft Start into Pre-Biased Load
  • Internal Soft Start: 4.1 ms
  • Extendable Soft-Start Time by External Capacitor
  • Output Voltage Tracking Capability
  • Precision Enable to Program System UVLO
  • Output Short-Circuit Protection With Hiccup Mode
  • Overtemperature Thermal Shutdown Protection
  • Create a Custom Design Using the LM43601 With the WEBENCH® Power Designer

The LM43601 regulator is an easy to use synchronous step-down DC-DC converter capable of driving up to 1 A of load current from an input voltage ranging from 3.5 V to 36 V (42 V transient). The LM43601 provides exceptional efficiency, output accuracy, and dropout voltage in a very small solution size. An extended family is available in 0.5-A, 2-A and 3-A load current options in pin-to-pin compatible packages. Peak-current-mode control is employed to achieve simple control-loop compensation and cycle-by-cycle current limiting. Optional features such as programmable switching frequency, synchronization, power-good flag, precision enable, internal soft start, extendable soft start, and tracking provide a flexible and easy-to-use platform for a wide range of applications. Discontinuous conduction and automatic frequency modulation at light loads improve light load efficiency. The family requires few external components and pin arrangement allows simple, optimum PCB layout. Protection features include thermal shutdown, VCC undervoltage lockout, cycle-by-cycle current limit, and output short-circuit protection. The LM43601 device is available in the 16-leaded HTSSOP (PWP) package (6.6 mm × 5.1 mm × 1.2 mm) with 0.65-mm lead pitch. This device is pin-to-pin compatible with LM46000, LM46001, LM46002, LM43600, LM43602, and LM43603.

The LM43601 regulator is an easy to use synchronous step-down DC-DC converter capable of driving up to 1 A of load current from an input voltage ranging from 3.5 V to 36 V (42 V transient). The LM43601 provides exceptional efficiency, output accuracy, and dropout voltage in a very small solution size. An extended family is available in 0.5-A, 2-A and 3-A load current options in pin-to-pin compatible packages. Peak-current-mode control is employed to achieve simple control-loop compensation and cycle-by-cycle current limiting. Optional features such as programmable switching frequency, synchronization, power-good flag, precision enable, internal soft start, extendable soft start, and tracking provide a flexible and easy-to-use platform for a wide range of applications. Discontinuous conduction and automatic frequency modulation at light loads improve light load efficiency. The family requires few external components and pin arrangement allows simple, optimum PCB layout. Protection features include thermal shutdown, VCC undervoltage lockout, cycle-by-cycle current limit, and output short-circuit protection. The LM43601 device is available in the 16-leaded HTSSOP (PWP) package (6.6 mm × 5.1 mm × 1.2 mm) with 0.65-mm lead pitch. This device is pin-to-pin compatible with LM46000, LM46001, LM46002, LM43600, LM43602, and LM43603.

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Technical documentation

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Type Title Date
* Data sheet LM43601 3.5-V to 36-V, 1-A Synchronous Step-Down Voltage Converter datasheet (Rev. B) PDF | HTML 10 Jan 2018
Application note Semiconductor and IC Package Thermal Metrics (Rev. D) PDF | HTML 25 Mar 2024
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
Application note Understanding Inverting Buck-Boost Power Stages in Switch Mode Power Supplies (Rev. B) 12 Mar 2019
Application note Differences Between LM4600x/LM4360x A and Non-A OPNs 27 Mar 2018
Technical article DC/DC converter datasheets- current limit - part two PDF | HTML 05 Sep 2016
Technical article DC/DC converter datasheets: current limit - part one PDF | HTML 29 Aug 2016
More literature SIMPLE SWITCHER Synchronous Regulator Series (Rev. B) 08 Feb 2016
Technical article Inverting made simple by unleashing the buck PDF | HTML 19 May 2015
Application note Inverting Applications Made SIMPLE With LM4600x and LM4360x (Rev. B) 20 Feb 2015
Application note Thermal Design Made Simple With LM43603 and LM46002 15 Sep 2014
Application note Low EMI Layout Made SIMPLE With LM43600/1/2/3 and LM46000/1/2 (Rev. A) 12 Sep 2014
Application note Compensation Made SIMPLE With LM4360x, LM4600x 29 Jul 2014
EVM User's guide LM43601 EVM User's Guide 16 Apr 2014
Application note AN-1533 Overvoltage Protection Circuit for Automotive Load Dump (Rev. B) 06 May 2013
Application note AN-1997 Error Amplifier Limitations in High-Performance Regulator Applications (Rev. A) 06 May 2013
Application note AN-2162 Simple Success With Conducted EMI From DC-DC Converters (Rev. C) 24 Apr 2013
Application note AN-1149 Layout Guidelines for Switching Power Supplies (Rev. C) 23 Apr 2013
Application note AN-1197 Selecting Inductors for Buck Converters (Rev. B) 23 Apr 2013
Application note AN-1229 SIMPLE SWITCHER PCB Layout Guidelines (Rev. C) 23 Apr 2013
Application note AN-1520 A Guide to Board Layout for Best Thermal Resistance for Exposed Packages (Rev. B) 23 Apr 2013
Application note AN-1566 Techniques for Thermal Analysis of Switching Power Supply Designs (Rev. A) 23 Apr 2013
Application note AN-1889 How to Measure the Loop Transfer Function of Power Supplies (Rev. A) 23 Apr 2013
Application note AN-2155 Layout Tips for EMI Reduction in DC/ DC Converters (Rev. A) 23 Apr 2013
Application note Understanding and Applying Current-Mode Control Theory 19 Aug 2007
Application note Input and Output Capacitor Selection 19 Sep 2005
More literature SEM1600 Topic 4: Constructing Your Power Supply – Layout Considerations 12 Jul 2005
Application note AN-643 EMI/RFI Board Design (Rev. B) 03 May 2004

Design & development

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

Evaluation board

LM43601PWPEVM — LM43601PWP Synchronous Step-Down Converter Evaluation Module

The LM43601PWPEVM evaluation module (EVM) is a fully assembled and tested circuit for evaluating the LM43601PWP synchronous step-down converter. The EVM operates from an 3.5V to 36V input and provides a 3.3V output at 1A.

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

LM43601 Non-Inverting and Inverting PSpice Transient Model (Rev. A)

SNVM647A.ZIP (625 KB) - PSpice Model
Simulation model

LM43601 PSpice Average Model

SNVM648.ZIP (89 KB) - PSpice Model
Simulation model

LM43601 Unencrypted PSpice Average Model

SNVM721.ZIP (1 KB) - PSpice Model
Reference designs

TIDA-00885 — 9.8 GHz RF High Performance Synthesizer Operating From a Buck Converter Reference Design

The TIDA-00885 design utilizes the LMX2592 a low-noise, wideband RF PLL with integrated VCO that can produce an output frequency range from 20 MHz to 9.8 GHz. The LMX2592 has excellent performance, integrated phase noise of 49fs for 6GHz output making it an ideal low noise source. There are two (...)
Design guide: PDF
Schematic: PDF
Package Pins CAD symbols, footprints & 3D models
HTSSOP (PWP) 16 Ultra Librarian

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