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LMR33640

ACTIVE

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

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Data sheet

LMR33640

ACTIVE
Data sheet Order now

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. A) PDF | HTML 02 Mar 2021
Technical article 3 tips when designing a power stage for servo and AC drives 20 Nov 2019
EVM User's guide LMR33640EVM User's Guide 01 Nov 2019
Technical article Minimize the impact of the MLCC shortage on your power application 29 Mar 2019
Technical article How to increase system reliability and simplify design using DC/DC converters 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
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Simulation model

LMR33640A PSpice Unencrypted Transient Model

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

LMR33640D PSpice Unencrypted Transient Model

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

LMR336x0 Component Calculator

SNVR484.ZIP (938 KB)
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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 (...)
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