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AC/DC & DC/DC converters (integrated FET)

LMS3655-Q1

ACTIVE

5.5-A, 36-V synchronous, 400-kHz, step-down converter

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Data sheet

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LM61460-Q1 ACTIVE Automotive 3-V to 36-V, 6-A, low-noise synchronous step-down converter Smaller solution size, higher efficiency and lower EMI.

LMS3655-Q1

ACTIVE
Data sheet Order now

Product details

Iout (max) (A) 5.5 Vin (min) (V) 3.5 Vin (max) (V) 42 Type Converter 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 Control mode current mode Vout (min) (V) 1 Vout (max) (V) 15 Rating Automotive Operating temperature range (°C) -40 to 150
Iout (max) (A) 5.5 Vin (min) (V) 3.5 Vin (max) (V) 42 Type Converter 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 Control mode current mode Vout (min) (V) 1 Vout (max) (V) 15 Rating Automotive Operating temperature range (°C) -40 to 150
VQFN-HR (RNL) 22 20 mm² 5 x 4
  • 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
  • Create a custom design using the LMS3655-Q1 with the WEBENCH Power Designer
  • 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
  • Create a custom design using the LMS3655-Q1 with the WEBENCH Power Designer

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.

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

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Type Title Date
* Data sheet LMS3635-Q1 3.5-A, LMS3655-Q1 5.5-A, 36-V Synchronous, 400-kHz Step-Down Converter datasheet (Rev. C) PDF | HTML 01 Aug 2021
White paper Time-Saving and Cost-Effective Innovations for EMI Reduction (Rev. A) PDF | HTML 28 Nov 2023
Selection guide Automotive Infotainment EE Buck Converter/Controller Selection Guide (Rev. B) 15 Apr 2021
White paper 透過節省時間和成本的創新技術 降低電源中的EMI 04 Dec 2020
White paper 전원 공급 장치의 EMI 절감을 위한 시간 및 비용 효율적 혁신 04 Dec 2020
Technical article Optimizing flip-chip IC thermal performance in automotive designs PDF | HTML 11 Dec 2019
Technical article How to meet European Commission ADAS requirements with TI DC/DC converters PDF | HTML 09 May 2019
EVM User's guide LMS36x5-Q1 EVM User's Guide (Rev. A) 13 Apr 2018
Technical article Designing USB into challenging automotive applications PDF | HTML 04 Apr 2018
Application note Designing High Performance, Low-EMI, Automotive Power Supplies 30 Sep 2017

Design & development

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

Evaluation board

DS90UB971-Q1EVM — DS90UB971-Q1 evaluation module

The DS90UB971-Q1 evaluation module (EVM) is a functional board design for evaluating the DS90UB971-Q1 FPD-Link IV serializer. The DS90UB971-Q1 serializer represents the first generation in FPD-Link IV serializers and is designed to support ultra-high-speed sensors including 8MP+ imagers, satellite (...)
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Evaluation board

LMS3655AQEVM — LMS3655-Q1 5.5A, 5V Synchronous, 400kHz, Step-Down Converter Evaluation Module

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 (...)
User guide: PDF
Not available on TI.com
Evaluation board

LMS3655MQEVM — LMS3655-Q1 5.5A, 5V Synchronous, 400kHz, Step-Down Converter Evaluation Module

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 (...)
User guide: PDF
Not available on TI.com
Evaluation board

LMS3655NQEVM — LMS3655-Q1 5.5A, 3.3V Synchronous, 400kHz Step-Down Converter Evaluation Module

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

LMS36553-Q1 PSpice Transient Model

SNAM217.ZIP (105 KB) - PSpice Model
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Simulation model

LMS36553-Q1 Unencrypted PSpice Transient Model

SNAM218.ZIP (7 KB) - PSpice Model
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Simulation model

LMS36555-Q1 PSpice Transient Model

SNAM213.ZIP (108 KB) - PSpice Model
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Simulation model

LMS36555-Q1 Unencrypted PSpice Transient Model

SNAM214.ZIP (7 KB) - PSpice Model
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Simulation model

LMS3655A-Q1 PSpice Transient Model

SNAM216.ZIP (157 KB) - PSpice Model
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Simulation model

LMS3655A-Q1 Unencrypted PSpice Transient Model

SNAM215.ZIP (7 KB) - PSpice Model
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Reference designs

PMP20249 — CISPR 25 Class 4 Rated Design for Dual Automotive USB Charger Reference Design

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 (...)
Test report: PDF
Schematic: PDF
Reference designs

TIDA-01388 — CISPR 25 Class 5 Rated Dual Automotive USB Charger Reference Design With Full Front End Protection

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 (...)
Design guide: PDF
Schematic: PDF
Reference designs

TIDA-01253 — CISPR 25 Class 4 Automotive Dual Remote and Local USB Port Reference Design

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 (...)
Design guide: PDF
Schematic: PDF
Reference designs

TIDA-01524 — Automotive High Efficiency Power Front End and Multi-Phase Processor Supply Reference Design

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 (...)
Design guide: PDF
Schematic: PDF
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