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LMQ644A0-Q1

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Automotive, 36V, 10A, low-IQ dual-output synchronous step-down converter

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Data sheet

LMQ644A0-Q1

ACTIVE
Data sheet Order now

Product details

Rating Automotive Operating temperature range (°C) -40 to 150 Type Converter Iout (max) (A) 10 Vin (min) (V) 3 Vin (max) (V) 36 Switching frequency (min) (kHz) 400 Switching frequency (max) (kHz) 2.2, 2200 Features Enable, Frequency synchronization, Over Current Protection, Power good, Spread Spectrum, Synchronous Rectification, Wettable flanks package EMI features Low parasitic Hotrod packaging, Spread Spectrum Control mode current mode Vout (min) (V) 0.8 Vout (max) (V) 20 Iq (typ) (µA) 40 Duty cycle (max) (%) 98
Rating Automotive Operating temperature range (°C) -40 to 150 Type Converter Iout (max) (A) 10 Vin (min) (V) 3 Vin (max) (V) 36 Switching frequency (min) (kHz) 400 Switching frequency (max) (kHz) 2.2, 2200 Features Enable, Frequency synchronization, Over Current Protection, Power good, Spread Spectrum, Synchronous Rectification, Wettable flanks package EMI features Low parasitic Hotrod packaging, Spread Spectrum Control mode current mode Vout (min) (V) 0.8 Vout (max) (V) 20 Iq (typ) (µA) 40 Duty cycle (max) (%) 98
VQFN-FCRLF (RXA) 24 20 mm² 5 x 4
  • AEC-Q100 qualified for automotive applications:
    • Device temperature grade 1: –40°C to +125°C ambient operating temperature
    • Operation up to 150°C junction temperature
  • Functional Safety-Capable
  • Designed for Low EMI
    • Symmetrical input voltage pins with > 1mm clearance to ground
    • Four 22nF integrated VIN to GND bypass capacitors
      • Two bypass capacitors placed in series between each VIN and GND for high reliability
    • Pin selectable spread spectrum option
    • Pin selectable FPWM or auto mode operation
    • Enhanced HotRod™ QFN (25) package with wettable flanks
    • Switching frequency from 100kHz to 2.2MHz
    • Meets CISPR 25 class 5 EMI requirements
  • Single and dual-output features
    • Wide input voltage range of 3V to 36V
    • 1% accurate fixed 3.3V, 5V or adjustable outputs from 0.8V to 20V
    • Hiccup-mode overcurrent protection and thermal shutdown protection with hysteresis
    • Precision ENABLE and PGOOD functions
    • 50ns tON(min) for high VIN / VOUT ratio
    • 80ns tOFF(min) for low dropout
  • Versatile dual-output operation
    • Shutdown mode current: 0.5µA typical
    • No-load standby current: 9µA typical
    • Built-in compensation and 3ms soft start
    • Independent precision ENABLE and PGOOD
  • Adaptable single-output operation
    • > 95% efficient for an 8A load, single output, VIN =12V, VOUT = 5V
    • External compensation and adjustable soft start
    • PGOOD, SYNCIN, and SYNCOUT functions
  • AEC-Q100 qualified for automotive applications:
    • Device temperature grade 1: –40°C to +125°C ambient operating temperature
    • Operation up to 150°C junction temperature
  • Functional Safety-Capable
  • Designed for Low EMI
    • Symmetrical input voltage pins with > 1mm clearance to ground
    • Four 22nF integrated VIN to GND bypass capacitors
      • Two bypass capacitors placed in series between each VIN and GND for high reliability
    • Pin selectable spread spectrum option
    • Pin selectable FPWM or auto mode operation
    • Enhanced HotRod™ QFN (25) package with wettable flanks
    • Switching frequency from 100kHz to 2.2MHz
    • Meets CISPR 25 class 5 EMI requirements
  • Single and dual-output features
    • Wide input voltage range of 3V to 36V
    • 1% accurate fixed 3.3V, 5V or adjustable outputs from 0.8V to 20V
    • Hiccup-mode overcurrent protection and thermal shutdown protection with hysteresis
    • Precision ENABLE and PGOOD functions
    • 50ns tON(min) for high VIN / VOUT ratio
    • 80ns tOFF(min) for low dropout
  • Versatile dual-output operation
    • Shutdown mode current: 0.5µA typical
    • No-load standby current: 9µA typical
    • Built-in compensation and 3ms soft start
    • Independent precision ENABLE and PGOOD
  • Adaptable single-output operation
    • > 95% efficient for an 8A load, single output, VIN =12V, VOUT = 5V
    • External compensation and adjustable soft start
    • PGOOD, SYNCIN, and SYNCOUT functions

The LMQ644xx-Q1 is a 36V, synchronous, buck, DC/DC converter for high-current single or dual outputs. The device uses an interleaved, stackable, current-mode control architecture for easy loop compensation, fast transient response, excellent load and line regulation, and accurate current sharing with an output clock supporting up to 6 phases for currents up to 36A. A high-side switch minimum on-time of 50ns gives large step-down ratios, enabling the direct conversion from 12V, 24V, or automotive inputs to low-voltage rails for reduced system complexity and design cost.

The LMQ644xx-Q1 incorporates spread spectrum in an optimized enhanced HotRod QFN package, with wettable flanks, and four 22nF high frequency integrated capacitors to minimize EMI. Dual Random Spread Spectrum (DRSS) frequency hopping is set to ±10% (typical), drastically reducing emissions through a combination of triangular and pseudo-random modulation. A bias pin allows the LMQ644xx-Q1 to save losses by powering the device from the output of the converter, achieving a 9µA no-load quiescent current to extend the operating run-time in battery-powered systems. The LMQ644xx-Q1 can maintain high efficiency light-load operation even when stacking multiple devices for high efficiency over the full load range.

The LMQ644xx-Q1 is a 36V, synchronous, buck, DC/DC converter for high-current single or dual outputs. The device uses an interleaved, stackable, current-mode control architecture for easy loop compensation, fast transient response, excellent load and line regulation, and accurate current sharing with an output clock supporting up to 6 phases for currents up to 36A. A high-side switch minimum on-time of 50ns gives large step-down ratios, enabling the direct conversion from 12V, 24V, or automotive inputs to low-voltage rails for reduced system complexity and design cost.

The LMQ644xx-Q1 incorporates spread spectrum in an optimized enhanced HotRod QFN package, with wettable flanks, and four 22nF high frequency integrated capacitors to minimize EMI. Dual Random Spread Spectrum (DRSS) frequency hopping is set to ±10% (typical), drastically reducing emissions through a combination of triangular and pseudo-random modulation. A bias pin allows the LMQ644xx-Q1 to save losses by powering the device from the output of the converter, achieving a 9µA no-load quiescent current to extend the operating run-time in battery-powered systems. The LMQ644xx-Q1 can maintain high efficiency light-load operation even when stacking multiple devices for high efficiency over the full load range.

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Technical documentation

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Type Title Date
* Data sheet LMQ644xx-Q1 3V to 36V, Low IQ , Dual 6/5/4A, Automotive Buck Converter Optimized for Power Density and Low EMI datasheet (Rev. A) PDF | HTML 08 Jul 2024
EVM User's guide LMQ644A2QEVM-D2100 36-V, Dual, 6-A Outputs, Synchronous, Buck Converter PDF | HTML 10 Jul 2023
EVM User's guide LMQ644A2QEVM-S2100 36-V, 12-A, Single-Output, Dual- Phase, Synchronous Buck PDF | HTML 10 Jul 2023
User guide LMQ644A2-Q1 6-Phase Buck Regulator Design for Automotive ADAS Applications PDF | HTML 05 Jul 2023
Functional safety information LMQ644xx-Q1 Functional Safety FIT Rate, FMD and Pin FMA PDF | HTML 27 Jun 2023

Design & development

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

Evaluation board

LM644A2QEVM-S2100T — LM644A2-Q1 evaluation module

The LM644A2QEVM-S2100T showcases the features and performance of the LM644A2-Q1 dual buck DC/DC converter with integrated power MOSFETs. The evaluation module provides a single 12A output with dual-phase interleaved configuration. The output voltages can be programmed to a fixed 3.3V, 5V or (...)
User guide: PDF | HTML
Not available on TI.com
Evaluation board

LMQ644A2QEVM-D2100 — LMQ644A2-Q1 evaluation module for dual-output synchronous step-down converter

The LMQ644A2QEVM-D2100 evaluation module (EVM) evaluates the features and performance of the LMQ644A2-Q1, dual buck DC/DC converter with integrated power MOSFETs. The EVM provides dual 6 A outputs. The output voltage can be individually programmed to a fixed 3.3 V and 5 V or adjustable using (...)

User guide: PDF | HTML
Not available on TI.com
Evaluation board

LMQ644A2QEVM-S2100 — LMQ644A2-Q1 evaluation module for single-output synchronous step-down converter

The LMQ644A2QEVM-S2100 evaluation module (EVM) evaluates the features and performance of the LMQ644A2-Q1, dual buck DC/DC converter with integrated power MOSFETs. The EVM provides 12 A output. The output voltage can be individually programmed to a fixed 3.3 V and 5 V or adjustable using external (...)

User guide: PDF | HTML
Not available on TI.com
Simulation model

LMQ644A0-Q1 PSpice Transient Model (Rev. A)

SLVME25A.ZIP (1204 KB) - PSpice Model
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Calculation tool

LMQ644XX-DESIGN-CALC — LMQ644XX quick-start design tool

This stand-alone tool facilitates and assists with the design of a DC/DC buck regulator based on the LM(Q)64480/A0/A2-Q1 dual channel buck converter. The user can expeditiously arrive at an optimized design to meet the application requirements.
Supported products & hardware

Supported products & hardware

Products
AC/DC & DC/DC converters (integrated FET)
LMQ64480-Q1 — Automotive, 36V, 8A, low-IQ dual-output synchronous step-down converter LMQ644A0-Q1 — Automotive, 36V, 10A, low-IQ dual-output synchronous step-down converter LMQ644A2-Q1 — Automotive, 36V, 12A, low-IQ dual-output synchronous step-down converter
Download
Reference designs

PMP23117 — 3.3-V, 24-A, four-phase reference design for automotive applications

This four-phase reference design provides 3.3 VOUT at 24 A from a 3.8-V to 16-V automotive power source. The design uses two LMQ644A2-Q1 dual-channel synchronous buck regulators operating at a nominal switching frequency of 500 kHz. Forced pulse width modulation (FPWM) or pulse frequency (...)
Test report: PDF
Package Pins CAD symbols, footprints & 3D models
VQFN-FCRLF (RXA) 24 Ultra Librarian
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Ordering & quality

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