Texas Instruments LMR38015S5QDRRRQ1

Overview

LMR38015S5QDRRRQ1 from Texas Instruments is an AEC-Q100 Grade 1 automotive synchronous buck converter delivering 1.5A continuous output at fixed 5V, operating from 4.2V to 80V input with 40µA quiescent current and integrated spread-spectrum EMI reduction - deployed in 48V mild-hybrid ECU bias supplies and battery management systems.

For engineers reviewing the LMR38015S5QDRRRQ1 datasheet, LMR38015S5QDRRRQ1 pinout, LMR38015S5QDRRRQ1 application, or LMR38015S5QDRRRQ1 equivalent, key selection criteria include its fixed-5V output configuration, 12-pin WSON wettable flank package with PowerPAD™, ±1.5% reference tolerance over –40°C to +150°C, and functional safety documentation support for ISO 26262 ASIL-B system integration.

Technical Context

The LMR38015S5QDRRRQ1 implements peak-current mode control with internal compensation, enabling stable regulation across wide input ranges without external loop components. Its fixed 5V output eliminates FB resistor divider requirements, simplifying layout and reducing BOM count while maintaining ±1.5% output accuracy over temperature.

It integrates high-side (303mΩ) and low-side (133mΩ) MOSFETs, supports frequency synchronization from 300kHz to 2.1MHz via RT/SYNC pin, and features precision enable with 1.1–1.25V logic threshold and open-drain power-good flag with built-in 45µs glitch filter - all qualified for automotive junction temperatures up to +150°C.

Key Specifications

Pinout & Package

LMR38015S5QDRRRQ1 uses a 12-pin WSON (DRR) package with 3mm × 3mm footprint and wettable flanks for automated optical inspection (AOI). The exposed thermal pad (EP) must be soldered to PCB ground plane for optimal thermal performance (R_θJC(bot) = 4.7°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LMR38015S5QDRRRQ1, the LMR38015FS5QDRRRQ1 trades 35µA higher quiescent current for FPWM stability, while LM61480QRNRRQ1 offers greater current headroom at the expense of input voltage range and EMI features - making LMR38015S5QDRRRQ1 uniquely balanced for 48V mild-hybrid bias rails.

Availability

LMR38015S5QDRRRQ1 is available at Aetrix Electronics and suitable for automotive inverter bias supplies, 48V mild-hybrid ECU power, and battery management system applications requiring stable component supply across extended product lifecycles.

Supply support for LMR38015S5QDRRRQ1 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 power management technologies, with deep expertise in automotive-grade reliability and functional safety.

The LMR38015-Q1 product line delivers high-voltage, low-I_Q synchronous buck converters engineered specifically for automotive 12V/24V/48V systems - emphasizing AEC-Q100 qualification, EMI robustness, and seamless integration into ASIL-B–capable power architectures.

FAQ

What is the output voltage configuration of the LMR38015S5QDRRRQ1?

The LMR38015S5QDRRRQ1 is factory-configured for fixed 5.0V output, eliminating the need for external feedback resistors. Its internal reference maintains ±1.5% accuracy over –40°C to +150°C junction temperature, and the FB pin must be directly connected to VOUT per datasheet guidance - no resistor divider is permitted or required for this variant.

Does the LMR38015S5QDRRRQ1 support external frequency synchronization?

Yes, the LMR38015S5QDRRRQ1 supports external clock synchronization via the RT/SYNC pin across 300kHz to 2.1MHz. When driven with a valid square wave (≥2.0V high, ≤0.6V low, >50ns pulse width), the internal PLL locks to the external signal, enabling deterministic EMI reduction and system-level timing alignment - critical for multi-converter automotive platforms.

How does the LMR38015S5QDRRRQ1 handle cold-crank conditions in automotive systems?

The LMR38015S5QDRRRQ1 sustains regulation down to 4.2V input with up to 97% duty cycle, allowing uninterrupted 5V output during engine cranking events where battery voltage dips below 6V. Its ability to operate at nearly unity duty cycle - combined with integrated pre-biased start-up - prevents brownouts in safety-critical ECUs without external boost circuitry.

What thermal performance can be expected from the LMR38015S5QDRRRQ1 in a typical automotive PCB layout?

In a standard 4-layer PCB with 2oz copper and the thermal pad fully soldered to a 4cm² ground plane, the LMR38015S5QDRRRQ1 achieves R_{θJA(effective)} ≈ 23.0°C/W. At 1.5A load and 24V input, junction temperature rise remains below 65°C above ambient - well within the +150°C AEC-Q100 Grade 1 limit, even at +85°C ambient under hood.

Is the LMR38015S5QDRRRQ1 compatible with functional safety development per ISO 26262?

Yes, the LMR38015S5QDRRRQ1 is functional safety-capable with documentation available to support ISO 26262 ASIL-B system design. It includes diagnostic features such as power-good flag with glitch filtering, thermal shutdown with hysteresis, cycle-by-cycle current limiting, and precise enable threshold - all verified across the full –40°C to +150°C temperature range per AEC-Q100 Grade 1.