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Product details

Parameters

Vin (Min) (V) 3.5 Vin (Max) (V) 42 Vout (Min) (V) 1 Vout (Max) (V) 15 Iout (Max) (A) 5.5 Iq (Typ) (mA) 0.015 Iq (Typ) (uA) 15 Switching frequency (Min) (kHz) 250 Switching frequency (Max) (kHz) 500 Features Enable, Forced PWM, Frequency Synchronization, Light Load Efficiency, Over Current Protection, Power Good, Pre-Bias Start-Up, Spread Spectrum, Synchronous Rectification, Wettable Flanks Package Operating temperature range (C) -40 to 125 Rating Catalog Regulated outputs (#) 1 open-in-new Find other Buck converters (integrated switch)

Package | Pins | Size

VQFN-HR (RNL) 22 20 mm² 4 x 5 open-in-new Find other Buck converters (integrated switch)

Features

  • 96% Peak Efficiency While Converting 12 V to 5 V
  • Low EMI and Switch Noise
    • Minimized Switch Node Ringing
    • Pseudo-Random Spread Spectrum
  • 400-kHz (±10%) Fixed Switching Frequency
  • –40°C to +150°C Junction Temperature Range
  • External Frequency Synchronization
  • RESET Output With Internal Filter and 3-ms Release Timer
  • Automatic Light Load Mode for Improved Efficiency
  • Pin-Selectable Forced PWM Mode
  • Built-In Compensation, Soft Start, Current Limit, Thermal Shutdown, and UVLO
  • 0.35-V Dropout With 3.5-A Load at 25°C (Typical)
  • 32-µA IQ_VIN: Quiescent Current at 3.3 VOUT and No Load (Typical)
  • 5.5-A Continuous Load Current
  • Adjustable Output Voltage (1 V to 20 V)
  • ±1.5% Reference Voltage Tolerance
  • 4-mm × 5-mm, 0.5-mm Pitch SON Package

All trademarks are the property of their respective owners.

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Description

The LMS3655 synchronous buck regulators are optimized for high performance applications, providing an adjustable output of 1 V to 20 V. Seamless transition between PWM and PFM modes, along with a low quiescent current, ensures high efficiency and superior transient responses at all loads.

Advanced high-speed circuitry allows the LMS3655 to regulate an input of 24 V to an output of 3.3 V at a fixed frequency of 400 kHz while also enabling a continuous load current of 5.5 A. An innovative frequency foldback architecture allows this device to regulate a 3.3-V output from an input voltage of only 3.5 V. The input voltage can range up to 36 V, with transient tolerance up to 42 V, easing input surge protection design.

An open-drain reset output, with built-in filtering and delay, provides a true indication of system status. This feature negates the requirement for an additional supervisory component, saving cost and board space.

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Technical documentation

= Top documentation for this product selected by TI
No results found. Please clear your search and try again. View all 6
Type Title Date
* Datasheet LMS3655 5.5-A, 36-V Synchronous, 400-kHz DC-DC Step-Down Converter datasheet (Rev. B) Mar. 01, 2018
Selection guides Buck Converter Quick Reference Guide (Rev. A) Mar. 31, 2020
Technical articles Minimize the impact of the MLCC shortage on your power application Mar. 29, 2019
User guides LMS36x5-Q1 EVM User's Guide (Rev. A) Apr. 13, 2018
Technical articles Powering up the performance of sensitive test and measurement systems Oct. 17, 2017
Application notes Designing High Performance, Low-EMI, Automotive Power Supplies Sep. 30, 2017

Design & development

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

Hardware development

EVALUATION BOARDS Download
document-generic User guide
75
Description
The LMS3655AQEVM evaluation module (EVM) demonstrates the capabilities of the LMS3655 automotive integrated buck converter. For optimized EMI performance, the EVM has an EMI filter on the back side that assists with noise reduction. The user can choose to bypass that EMI filter using  (...)
Features
  • High Efficiency with 400kHz and Auto Light Mode PFM/PWM or Forced PWM Mode operation
  • /RESET Power Good output with 3ms delay on timer
  • External Frequency Synchronisation Input
  • Low EMI
  • Fully Synchronous with integrated HS and LS FET
EVALUATION BOARDS Download
document-generic User guide
75
Description
The LMS3655MQEVM evaluation module (EVM) demonstrates the capabilities of the LMS3655-Q1 automotive integrated buck converter. For optimized EMI performance, the LMS3655-Q1 has Spread Spectrum built in and the  EVM has an EMI filter on the back side that assists with noise reduction. The (...)
Features
  • High Efficiency with 400kHz and Auto Light Mode PFM/PWM or Forced PWM Mode operation
  • /RESET Power Good output with 3ms delay on timer
  • Low EMI
  • Fully Synchronous with integrated HS and LS FET

Design tools & simulation

SIMULATION TOOLS Download
PSpice® for TI design and simulation tool
PSPICE-FOR-TI — 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 (...)
Features
  • Leverages Cadence PSpice Technology
  • Preinstalled library with a suite of digital models to enable worst-case timing analysis
  • Dynamic updates ensure you have access to most current device models
  • Optimized for simulation speed without loss of accuracy
  • Supports simultaneous analysis of multiple products
  • (...)

Reference designs

REFERENCE DESIGNS Download
CISPR 25 Class 4 Rated Design for Dual Automotive USB Charger Reference Design
PMP20249 — PMP20249 is an EMI optimized design for dual automotive USB charger system utilizing the LMS3635 and LMS3655 regulator ICs (400kHz fully-integrated synchronous buck for automotive application) and TPS2549 USB switch (TPS2549-Q1 automotive USB charging port controller with integrated power switch (...)
document-generic Schematic document-generic User guide
REFERENCE DESIGNS Download
USB Type-C™ DFP 5V 1.5A + USB Type-A 5V 2.4A Car Charger Reference Design
PMP40269 — PMP40269 is a dual port car charger reference design. It has a USB Type-C™ port and a USB type-A port. The USB Type-C port can provide 5V 1.5A to USB Type-C device. The type-A port can provide 5V 2.4A, it is also capable of compensating for the effects on voltage droop when a smartphone or (...)
document-generic Schematic document-generic User guide

CAD/CAE symbols

Package Pins Download
VQFN-HR (RNL) 22 View options

Ordering & quality

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