Texas Instruments LMR38025SQDRRRQ1

Overview

LMR38025SQDRRRQ1 from Texas Instruments is an AEC-Q100 Grade 1 automotive synchronous buck converter delivering 2.5A continuous output current across a 4.2V to 80V input range, featuring 40µA quiescent current, adjustable 200kHz–2.2MHz switching frequency, and integrated synchronous rectification in a 3mm × 3mm WSON-12 package. It supports prebiased start-up and operates at up to 97% duty cycle for 48V mild-hybrid ECU bias supplies.

For engineers reviewing the LMR38025SQDRRRQ1 datasheet, LMR38025SQDRRRQ1 pinout, LMR38025SQDRRRQ1 application, or LMR38025SQDRRRQ1 equivalent, key selection criteria include its ultra-low IQ for always-on systems, spread-spectrum EMI reduction, precision enable with UVLO control, and functional safety documentation support for ASIL-B–capable designs.

Technical Context

The LMR38025SQDRRRQ1 employs fixed-frequency peak-current mode control with internal compensation, enabling stable regulation using minimal external components. Its high-side/low-side NMOS power stage features R_DS(on) of 303mΩ/133mΩ and supports PFM operation for light-load efficiency or FPWM mode for constant-frequency, low-ripple performance.

It integrates a precision 1.0V reference (±1.5% over –40°C to +150°C), programmable soft-start (4.2ms), and open-drain power-good flag with built-in glitch filtering (45µs). The RT/SYNC pin enables either resistor-based frequency setting or external clock synchronization from 300kHz to 2.1MHz.

Key Specifications

Pinout & Package

LMR38025SQDRRRQ1 uses a 12-pin WSON (DRR) package with wettable flanks and integrated PowerPAD™ thermal pad (3mm × 3mm footprint). The exposed pad must be soldered to PCB ground for optimal thermal performance (R_θJB = 21.7°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous buck converter applications.

Compared with LMR38025FSQDRRRQ1, the LMR38025SQDRRRQ1 trades FPWM for slightly lower system cost and complexity, while retaining identical EMI mitigation and thermal robustness; versus LMR36520QDPWRQ1, it delivers higher current, wider input range, and comprehensive automotive-grade features essential for 48V MHEV control units.

Availability

LMR38025SQDRRRQ1 is available at Aetrix Electronics and suitable for automotive inverter bias supplies, 48V mild-hybrid ECU power rails, and battery management system auxiliary regulators requiring stable component supply across extended product lifecycles.

Supply support for LMR38025SQDRRRQ1 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and automotive-grade power management solutions with decades of automotive qualification experience.

The LMR38025SQDRRRQ1 belongs to TI's SIMPLE SWITCHER® automotive buck converter family, engineered specifically for high-reliability 48V/12V DC/DC conversion in engine bay and powertrain control modules.

FAQ

What is the maximum input voltage rating for the LMR38025SQDRRRQ1?

The LMR38025SQDRRRQ1 has an absolute maximum input voltage rating of 85V, with recommended operating range from 4.2V to 80V. This allows safe operation during automotive load-dump transients and cold-crank conditions while maintaining regulation down to 4.2V input at near-100% duty cycle. Exceeding 85V may cause permanent damage per Absolute Maximum Ratings.

Does the LMR38025SQDRRRQ1 support external frequency synchronization?

Yes, the LMR38025SQDRRRQ1 supports external clock synchronization via the RT/SYNC pin across a 300kHz to 2.1MHz range. When driven with a valid square wave (high ≥2.0V, low ≤0.6V, pulse width ≥50ns), the internal PLL locks to the external signal, enabling EMI reduction through synchronized switching in multi-rail systems.

How does the LMR38025SQDRRRQ1 handle prebiased output conditions during startup?

The LMR38025SQDRRRQ1 supports prebiased output start-up, allowing safe turn-on when the output capacitor is already charged. Internal circuitry prevents reverse current flow from VOUT into the IC, eliminating risk of damage or latch-up during hot-swap or backup supply transitions-critical for redundant power architectures in automotive ECUs.

What thermal performance can be expected from the LMR38025SQDRRRQ1 in a standard 2-layer PCB layout?

In a typical 2-layer PCB with 1oz copper and the thermal pad fully soldered to a 1cm² ground plane, the LMR38025SQDRRRQ1 achieves R_{θJA(effective)} ≈ 23.0°C/W (per datasheet). At 2.5A load and 24V input, this yields ~55°C junction rise above ambient-well within the +150°C max TJ limit. For higher ambient or sealed enclosures, adding thermal vias under the pad further reduces thermal resistance.

Is the LMR38025SQDRRRQ1 qualified for functional safety applications?

Yes, the LMR38025SQDRRRQ1 is functional safety-capable with documentation available-including FIT rate data, FMEDA reports, and safety manual-to support ISO 26262 ASIL-B system-level development. It is not ASIL-B certified out-of-box but provides the necessary hardware-level safety mechanisms (e.g., thermal shutdown, cycle-by-cycle current limit, power-good flag) and traceable design data for integration into safety-critical automotive subsystems.