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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, Fixed Output, Forced PWM, Frequency Synchronization, Light Load Efficiency, Over Current Protection, Power Good, Pre-Bias Start-Up, Soft Start Fixed, Spread Spectrum, Synchronous Rectification, Wettable Flanks Package Operating temperature range (C) -40 to 150 Rating Automotive 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

  • AEC-Q100 Qualified for Automotive Applications
    • Device Temperature Grade 1: –40°C to +125°C Ambient Operating Temperature
    • Device HBM Classification Level 2
    • Device CDM Classification Level C6
  • 96% Peak Efficiency While Converting 12 V to 5 V
  • Low EMI and Minimized Switch Node Ringing
  • 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)
  • 18-µA IQ_VIN: Quiescent Current at 3.3 VOUT and No Load (Typical)
  • Output Voltage: 5 V, 3.3 V, and ADJ (1 V to 20 V)
  • ±1.5% Reference Voltage Tolerance

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Description

The LMS3635-Q1 and LMS3655-Q1 synchronous buck regulators are optimized for high performance applications, providing an output voltage of 3.3 V, 5 V, or 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-Q1 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 8
Type Title Date
* Datasheet LMS3635-Q1 3.5-A, LMS3655-Q1 5.5-A, 36-V Synchronous, 400-kHz Step-Down Converter datasheet (Rev. B) Mar. 01, 2018
Technical articles Optimizing flip-chip IC thermal performance in automotive designs Dec. 11, 2019
Technical articles How to meet European Commission ADAS requirements with TI DC/DC converters May 08, 2019
Technical articles Minimize the impact of the MLCC shortage on your power application Mar. 29, 2019
Selection guides Automotive Infotainment EE Buck Converter/Controller Selection Guide (Rev. A) Jan. 15, 2019
User guides LMS36x5-Q1 EVM User's Guide (Rev. A) Apr. 13, 2018
Technical articles Designing USB into challenging automotive applications Apr. 04, 2018
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
EVALUATION BOARDS Download
document-generic User guide
75
Description
The LMS3655NQEVM 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 time/RESET Power Good output with 3ms delay on timer
  • External Frequency Synchronisation Input
  • Low EMI
  • Fully Synchronous with integrated HS and LS FET

Design tools & simulation

SIMULATION MODELS Download
SNAM213.ZIP (108 KB) - PSpice Model
SIMULATION MODELS Download
SNAM214.ZIP (7 KB) - PSpice Model
SIMULATION MODELS Download
SNAM215.ZIP (7 KB) - PSpice Model
SIMULATION MODELS Download
SNAM216.ZIP (157 KB) - PSpice Model
SIMULATION MODELS Download
SNAM217.ZIP (105 KB) - PSpice Model
SIMULATION MODELS Download
SNAM218.ZIP (7 KB) - PSpice Model
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
CISPR 25 Class 5 Rated Dual Automotive USB Charger Reference Design With Full Front End Protection
TIDA-01388 — TIDA-01388 is a 21 W dual automotive USB charger solution featuring complete front end protection with small size. The system can clamp fast high-voltage electrical transients and maintain operation through these events. It can also properly respond to a reverse battery polarity event and shut down (...)
document-generic Schematic document-generic User guide
REFERENCE DESIGNS Download
CISPR 25 Class 4 Automotive Dual Remote and Local USB Port Reference Design
TIDA-01253 — This automotive media port design allows customers to accelerate media port systems by taking advantage of a complete reference design comprising analog AEC-100-qualified integrated circuits (ICs). The reference design is specified for automotive media ports that require both local-port and (...)
document-generic Schematic document-generic User guide
REFERENCE DESIGNS Download
Automotive High Efficiency Power Front End and Multi-Phase Processor Supply Reference Design
TIDA-01524 — This processor supply reference design is an automotive power solution for use in highperformance, single-core-voltage application processors in advanced driver assistance systems (ADASs). This design can support core supply currents up to 10 A at 0.9 V. The design can also operate with a wide input (...)
document-generic Schematic document-generic User guide

CAD/CAE symbols

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

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