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LMR33640

ACTIVE

SIMPLE SWITCHER® 3.8-V to 36-V, 4-A step-down converter in SOIC-8 package

Product details

Vin (min) (V) 3.8 Vin (max) (V) 36 Vout (min) (V) 1 Vout (max) (V) 24 Iout (max) (A) 4 Iq (typ) (mA) 0.024 Switching frequency (min) (kHz) 400 Switching frequency (max) (kHz) 1000 Features Enable, Light Load Efficiency, Over Current Protection, Power good, Pre-Bias Start-Up, Synchronous Rectification, Wettable flanks package Operating temperature range (°C) -40 to 125 Rating Catalog TI functional safety category Functional Safety-Capable Regulated outputs (#) 1 Control mode current mode Duty cycle (max) (%) 98 Type Converter
Vin (min) (V) 3.8 Vin (max) (V) 36 Vout (min) (V) 1 Vout (max) (V) 24 Iout (max) (A) 4 Iq (typ) (mA) 0.024 Switching frequency (min) (kHz) 400 Switching frequency (max) (kHz) 1000 Features Enable, Light Load Efficiency, Over Current Protection, Power good, Pre-Bias Start-Up, Synchronous Rectification, Wettable flanks package Operating temperature range (°C) -40 to 125 Rating Catalog TI functional safety category Functional Safety-Capable Regulated outputs (#) 1 Control mode current mode Duty cycle (max) (%) 98 Type Converter
HSOIC (DDA) 8 29.4 mm² 4.9 x 6
  • Functional Safety-Capable
  • Configured for rugged industrial applications
    • Input voltage range: 3.8 V to 36 V
    • Output voltage range: 1 V to 24 V
    • Peak-current mode control
    • Junction temperature range: –40°C to +125°C
    • Ease-of-use SOIC package
  • Well-suited for scalable industrial power supplies
    • Pin compatible with:
    • 400-kHz and 1-MHz frequency
    • Integrated compensation helps reduce solution size, cost, and design complexity
  • High-efficiency solution
    • Peak efficiency > 95%
    • Low shutdown quiescent current of 5 µA
    • Low operating quiescent current of 24 µA
  • Flexible system interface
    • Power-good flag and precision enable
  • Create a custom design using the LMR33640 with the WEBENCH Power Designer
  • Use TPSM53604 module for faster time to market
  • Functional Safety-Capable
  • Configured for rugged industrial applications
    • Input voltage range: 3.8 V to 36 V
    • Output voltage range: 1 V to 24 V
    • Peak-current mode control
    • Junction temperature range: –40°C to +125°C
    • Ease-of-use SOIC package
  • Well-suited for scalable industrial power supplies
    • Pin compatible with:
    • 400-kHz and 1-MHz frequency
    • Integrated compensation helps reduce solution size, cost, and design complexity
  • High-efficiency solution
    • Peak efficiency > 95%
    • Low shutdown quiescent current of 5 µA
    • Low operating quiescent current of 24 µA
  • Flexible system interface
    • Power-good flag and precision enable
  • Create a custom design using the LMR33640 with the WEBENCH Power Designer
  • Use TPSM53604 module for faster time to market

The LMR33640 SIMPLE SWITCHER regulator is an easy-to-use, synchronous, step-down DC/DC converter that delivers best-in-class efficiency for rugged industrial applications. The LMR33640 drives up to 4 A of load current from an input of up to 36 V. The LMR33640 provides high light-load efficiency and output accuracy. Features such as a power-good flag and precision enable provide both flexible and easy-to-use solutions for a wide range of applications. The LMR33640 automatically folds back frequency at light load to improve efficiency. Protection features include thermal shutdown, input undervoltage lockout, cycle-by-cycle current limit, and hiccup short-circuit protection. Integration and internal compensation eliminates many external components and provides a pinout designed for a simple PCB layout. The feature set of the device is designed to simplify implementation for a wide range of end equipment. The LMR33640 is pin-to-pin compatible with the LMR33610, LMR33620, LMR33630 (36 V, 1 A/2, A/3 A), LMR36510 (65 V, 1 A), and LMR36520 (65 V, 2 A), completing the family of scalable SIMPLE SWITCHER power supplies. This minimizes the cost and effort associated with board layout modifications. The LMR33640 is available in an 8-pin HSOIC package.

The LMR33640 SIMPLE SWITCHER regulator is an easy-to-use, synchronous, step-down DC/DC converter that delivers best-in-class efficiency for rugged industrial applications. The LMR33640 drives up to 4 A of load current from an input of up to 36 V. The LMR33640 provides high light-load efficiency and output accuracy. Features such as a power-good flag and precision enable provide both flexible and easy-to-use solutions for a wide range of applications. The LMR33640 automatically folds back frequency at light load to improve efficiency. Protection features include thermal shutdown, input undervoltage lockout, cycle-by-cycle current limit, and hiccup short-circuit protection. Integration and internal compensation eliminates many external components and provides a pinout designed for a simple PCB layout. The feature set of the device is designed to simplify implementation for a wide range of end equipment. The LMR33640 is pin-to-pin compatible with the LMR33610, LMR33620, LMR33630 (36 V, 1 A/2, A/3 A), LMR36510 (65 V, 1 A), and LMR36520 (65 V, 2 A), completing the family of scalable SIMPLE SWITCHER power supplies. This minimizes the cost and effort associated with board layout modifications. The LMR33640 is available in an 8-pin HSOIC package.

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Technical documentation

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Type Title Date
* Data sheet LMR33640 SIMPLE SWITCHER 3.8-V to 36-V, 4-A Synchronous Step-down Converter datasheet (Rev. C) PDF | HTML 24 Nov 2020
Application note Working with Inverting Buck-Boost Converters (Rev. B) PDF | HTML 18 Oct 2022
Functional safety information LMR336x0 Functional Safety, FIT Rate, FMD and Pin FMA (Rev. B) PDF | HTML 06 Nov 2020
Technical article 3 tips when designing a power stage for servo and AC drives PDF | HTML 20 Nov 2019
EVM User's guide LMR33640EVM User's Guide 01 Nov 2019
Technical article How to increase system reliability and simplify design using DC/DC converters PDF | HTML 13 Jun 2016

Design & development

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Evaluation board

LMR33640EVM — 3.8-V to 36-V, 4-A step-down converter evaluation module

The LMR33640 evaluation module (EVM) is a fully assembled and tested circuit for evaluating the LMR33640ADDA synchronous step-down converer.
User guide: PDF
Not available on TI.com
Simulation model

LMR33640A PSpice Unencrypted Transient Model

SNVMBV0.ZIP (175 KB) - PSpice Model
Simulation model

LMR33640D PSpice Unencrypted Transient Model

SNVMBV1.ZIP (172 KB) - PSpice Model
Calculation tool

SNVR484 LMR336x0 Component Calculator

Supported products & hardware

Supported products & hardware

Products
Buck converters (integrated switch)
LMR33620 SIMPLE SWITCHER® 3.8V to 36V, 2A Synchronous Buck Converter With Ultra-Low EMI LMR33620-Q1 3.8-V to 36-V, 2-A synchronous step-down voltage converter LMR33630 SIMPLE SWITCHER® 3.8V to 36V, 3A Synchronous Buck Converter With Ultra-Low EMI LMR33630-Q1 3.8-V to 36-V, 3-A synchronous step-down voltage converter LMR33640 SIMPLE SWITCHER® 3.8-V to 36-V, 4-A step-down converter in SOIC-8 package LMR36015 4.2-V to 60-V, 1.5-A ultra-small synchronous step-down converter LMR36015-Q1 4.2-V to 60-V, 1.5-A ultra-small synchronous step-down converter
Simulation tool

PSPICE-FOR-TI — PSpice® for TI design and simulation tool

PSpice® for TI is a design and simulation environment that helps evaluate functionality of analog circuits. This full-featured, design and simulation suite uses an analog analysis engine from Cadence®. Available at no cost, PSpice for TI includes one of the largest model libraries in the (...)
Package Pins Download
HSOIC (DDA) 8 View options

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