Texas Instruments LMR38015SDRRR

Overview

LMR38015SDRRR from Texas Instruments is a synchronous buck DC/DC converter designed for wide-input industrial power rails, delivering 1.5A continuous output current across 4.2V–80V input, featuring 40µA quiescent current in PFM mode, adjustable 200kHz–2.2MHz switching frequency, and integrated high- and low-side MOSFETs in a 12-pin WSON package. It supports prebiased start-up, precision enable, and spread-spectrum EMI reduction for rugged transport and factory automation systems.

For engineers reviewing the LMR38015SDRRR datasheet, LMR38015SDRRR pinout, LMR38015SDRRR application, or LMR38015SDRRR equivalent, key selection criteria include its 97% max duty cycle for ultra-low dropout operation, ±1.5% reference voltage tolerance over temperature, RT/SYNC pin programmability, open-drain power-good flag with built-in glitch filtering, and thermal shutdown at 163°C - all critical for MHEV/EV auxiliary supplies and wireless infrastructure power delivery.

Technical Context

The LMR38015SDRRR employs fixed-frequency peak-current mode control with internal compensation, enabling stable regulation using minimal external components. Its dual-mode operation (PFM for light-load efficiency, FPWM disabled per Datasheet Table 4) ensures predictable behavior under dynamic loads while maintaining tight output voltage regulation via a 1.0V ±1.5% reference and feedback loop with <2.5% total output deviation.

It integrates high-side (303mΩ) and low-side (133mΩ) NMOS switches, supports frequency synchronization from 300kHz–2.1MHz, and implements frequency foldback to extend effective duty cycle beyond 97% during input dips - enabling reliable operation down to 4.2V VIN with near-100% on-time capability.

Key Specifications

Pinout & Package

LMR38015SDRRR is housed in a 3.0mm × 3.0mm 12-pin WSON package with wettable flanks and exposed thermal pad (EP), optimized for automated optical inspection and high thermal performance (R_θJA = 54.3°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LMR38015FDRRR and LMR36015SDDAR, the LMR38015SDRRR offers superior light-load efficiency via PFM mode and built-in EMI reduction - making it optimal for battery-backed industrial sensors and compact wireless nodes where thermal and spectral constraints dominate.

Availability

LMR38015SDRRR is available at Aetrix Electronics and suitable for industrial transport, wireless infrastructure, and factory automation applications requiring stable component supply, long-term lifecycle assurance, and traceable sourcing from authorized channels.

Supply support for LMR38015SDRRR 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 and embedded processing technologies, with decades of expertise in power management ICs for industrial, automotive, and communications markets.

The LMR38015SDRRR belongs to TI's SIMPLE SWITCHER® family - engineered for rugged, easy-to-deploy DC/DC conversion in harsh environments where wide input range, reliability, and minimal external components are essential.

FAQ

What is the maximum input voltage rating for the LMR38015SDRRR?

The LMR38015SDRRR has an absolute maximum input voltage rating of 85V across VIN to PGND, with recommended operating range from 4.2V to 80V. This allows robust operation in automotive and industrial settings where load-dump transients occur. The device maintains regulation down to 4.2V input, supporting cold-crank scenarios. Always observe derating guidelines above 80V for long-term reliability.

Does the LMR38015SDRRR support external frequency synchronization?

Yes, the LMR38015SDRRR supports external clock synchronization via the RT/SYNC pin, accepting square-wave inputs from 300kHz to 2.1MHz. When driven above the PLL upper threshold (~2V), the internal oscillator disables and locks to the external clock's falling edge. This feature enables deterministic EMI reduction and multi-rail synchronization in complex power systems using the LMR38015SDRRR.

How does the power-good (PG) flag behave during startup and fault conditions?

The LMR38015SDRRR's open-drain PG pin remains low during soft-start and asserts high only after V_OUT reaches and sustains 90–114% of the regulated value. It pulls low during overcurrent, thermal shutdown, or EN deactivation. With built-in 45µs glitch filtering, brief transients won't trigger false flags - ensuring reliable host processor signaling in real-world industrial deployments using the LMR38015SDRRR.

Can the LMR38015SDRRR operate with a precharged output capacitor?

Yes, the LMR38015SDRRR supports prebiased output start-up, allowing safe turn-on when the output capacitor is already charged. This prevents reverse current flow through internal MOSFETs and avoids damaging inrush into downstream circuitry. The feature is enabled by default and requires no configuration - a key advantage for hot-swap and redundant power architectures using the LMR38015SDRRR.

What thermal performance can be expected from the LMR38015SDRRR in a standard PCB layout?

In a typical 2-layer PCB with 1-in² 2oz copper thermal pad connected to the EP, the LMR38015SDRRR achieves R_θJA(effective) ≈ 23.0°C/W (per datasheet). At 1.5A load and 24V input, junction temperature rise is ~34.5°C above ambient - well within the 150°C max rating. For higher ambient or sealed enclosures, adding thermal vias under the EP further improves dissipation, ensuring reliable operation of the LMR38015SDRRR.