LMQ644A0QRXARQ1

Voltage Regulators - DC DC Switching Regulators Overview

The LMQ644A0QRXARQ1 is a 36V synchronous buck DC-DC converter designed for high-current single or dual outputs. It features an interleaved, stackable current-mode control architecture supporting up to six phases for currents up to 36A. The device offers a 50ns minimum high-side switch on-time, enabling direct conversion from 12V, 24V, or automotive inputs to low-voltage rails. It operates within an input voltage range of 3V to 36V and supports output voltages down to 0.8V. The component is housed in a VQFN-FCRLF (RXA) package with 24 pins, rated for operating temperatures from -40°C to +150°C.

Voltage Regulators - DC DC Switching Regulators Feature Summary

• Interleaved, stackable current-mode control architecture enables fast transient response and precise current sharing across multiple phases.
• 50ns high-side switch shortest on-time allows large step-down ratios for efficient direct conversion from standard automotive input voltages.
• Low quiescent current design minimizes power consumption during standby modes while maintaining stable regulation under varying load conditions.

Voltage Regulators - DC DC Switching Regulators Applications

• High-current single or dual output power distribution in automotive electronic control units
• Direct conversion from 12V or 24V automotive buses to low-voltage processor supply rails
• Power management systems requiring fast transient response and simplified loop compensation

Voltage Regulators - DC DC Switching Regulators Procurement Notes

Verify the specific suffix RXARQ1 confirms the VQFN-FCRLF package and automotive grade qualification. Ensure the ordering part number matches the required output configuration, as the LMQ644xx-Q1 series includes variants with different current ratings and pin configurations. Cross-reference the datasheet revision date to confirm compatibility with your system's thermal and electrical requirements before finalizing procurement.

Voltage Regulators - DC DC Switching Regulators Selection Notes

Select this component when designing systems requiring high efficiency at high currents with minimal external component count. The stackable architecture allows scaling current capacity by paralleling devices without complex current-sharing circuits. Consider the 50ns on-time limitation when selecting output voltage levels to ensure adequate duty cycle for stable operation. Verify that the thermal performance of the VQFN-FCRLF package meets the heat dissipation needs of the target application environment.

Voltage Regulators - DC DC Switching Regulators Part Context

This device belongs to the Texas Instruments LMQ644xx-Q1 family of automotive-grade synchronous buck converters. The family is engineered for robust performance in harsh automotive environments, offering high reliability and extended temperature ranges. The LMQ644A0 variant specifically provides dual-output capabilities with integrated current sharing, distinguishing it from single-output counterparts in the same series.

Voltage Regulators - DC DC Switching Regulators Replacement Considerations

Compatible substitutes include other members of the LMQ644xx-Q1 family, such as LMQ644A2-Q1, which offers similar functionality but with different current ratings. Ensure any replacement maintains the same package type (VQFN-FCRLF) and electrical specifications to preserve board layout and thermal design integrity without redesigning the power stage.

Voltage Regulators - DC DC Switching Regulators FAQ

What is the maximum number of phases supported by the LMQ644A0QRXARQ1?

The device supports up to six phases when stacked, allowing for total output currents up to 36A.

How does the device handle current sharing between phases?

It uses an interleaved current-mode control architecture that ensures excellent load regulation and precise current sharing without requiring external current-sharing components.

What is the minimum input voltage for this converter?

The minimum input voltage is 3V, allowing operation from low-voltage automotive sources or partially discharged batteries.