Texas Instruments LMR14050SDDAR

Overview

LMR14050SDDAR from Texas Instruments is a 40V input, 5A synchronous step-down DC-DC converter with integrated 90mΩ high-side MOSFET, 40µA quiescent current, 2.2MHz switching frequency capability, and internal compensation - designed for automotive battery regulation and industrial power supplies where compact size and low-noise operation are critical.

For engineers reviewing the LMR14050SDDAR datasheet, LMR14050SDDAR pinout, LMR14050SDDAR application, or LMR14050SDDAR equivalent, key selection considerations include its 4–40V input range, precision enable threshold (1.2V), 75ns minimum on-time, RT/SYNC frequency programming/synchronization, and thermal shutdown at 170°C.

Technical Context

The LMR14050SDDAR implements fixed-frequency peak current mode control with slope compensation to ensure stability at duty cycles >50%. Its sleep mode reduces quiescent current to 40µA under light load while maintaining regulation via COMP voltage clamping at 400mV.

It features an integrated bootstrap regulator enabling ~97% maximum duty cycle, with automatic BOOT capacitor recharge when BOOT–SW drops below 3.2V - critical for low-dropout operation. Protection includes cycle-by-cycle current limiting, output overvoltage protection (109% VREF trip), and thermal shutdown with 12°C hysteresis.

Key Specifications

Pinout & Package

LMR14050SDDAR uses an 8-pin HSOIC package with exposed thermal pad (DDA), measuring 4.9mm × 6mm. The PowerPAD™ thermal pad must be soldered to a dedicated PCB ground plane for optimal thermal performance (RθJC(bot) = 7.8°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar step-down converter applications.

Compared with LMR14050SDDAR, LMR14030SDDAR offers identical integration and ease of use at reduced current capacity, while TPS54560QDGQRQ1 trades simplicity for automotive qualification and extended input range - making LMR14050SDDAR optimal for cost-sensitive industrial and non-safety automotive designs requiring ultra-low IQ and plug-and-play operation.

Availability

LMR14050SDDAR is available at Aetrix Electronics and suitable for automotive battery regulation, industrial power supplies, and telecom/datacom systems requiring stable component supply, long-lifecycle support, and consistent parametric performance across production batches.

Supply support for LMR14050SDDAR 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 ICs, with decades of expertise in high-reliability DC-DC conversion and automotive-grade power solutions.

The LMR140xx SIMPLE SWITCHER® product line targets space-constrained, thermally demanding applications - delivering fully integrated, easy-to-use buck converters for industrial, automotive, and communications infrastructure without requiring loop compensation expertise.

FAQ

What is the absolute maximum input voltage rating for the LMR14050SDDAR?

The LMR14050SDDAR has an absolute maximum VIN-to-GND rating of 44V. Exceeding this voltage may cause permanent damage. For reliable operation, the recommended input range is 4V to 40V - sufficient to handle automotive load-dump events (per ISO 7637-2) and industrial 36V rails. Always include transient voltage suppression if system-level surges exceed 44V.

Does the LMR14050SDDAR require external compensation components?

No, the LMR14050SDDAR features internal compensation, eliminating the need for external Type-II or Type-III compensation networks. This simplifies design, reduces BOM count, and improves stability across varied output capacitor types and ESR values - a key advantage over controllers like the TPS54560 that require manual loop tuning.

How does the LMR14050SDDAR achieve ultra-low 40µA quiescent current?

The LMR14050SDDAR achieves 40µA IQ in sleep mode by disabling the high-side MOSFET, clamping the internal COMP voltage at 400mV, and reducing gate drive and oscillator activity - all while maintaining output regulation through periodic wake-up bursts. This behavior is confirmed in Section 6.3.3 of the datasheet and validated across –40°C to +125°C.

Can the LMR14050SDDAR synchronize to an external clock, and what are the timing requirements?

Yes, the LMR14050SDDAR supports synchronization via the RT/SYNC pin across 250kHz–2.3MHz. Required clock specs: high-level ≥1.7V, low-level ≤0.5V, minimum pulse width ≥30ns, and falling-edge alignment. When synchronized, the internal oscillator locks to the external edge, enabling EMI reduction in noise-sensitive systems such as radar or audio processing.

What thermal performance can be expected from the LMR14050SDDAR in a standard 2-layer PCB layout?

In a standard 2-layer PCB with the thermal pad fully soldered to a 1-in² copper pour connected to internal ground planes, the LMR14050SDDAR achieves RθJA ≈ 43.2°C/W. At 5A output and 12V input, junction temperature rise is ~216°C above ambient - so derating or enhanced copper (e.g., 4-layer with thermal vias) is required for full-load operation above 25°C ambient. Datasheet Figure 5-1 confirms >85% efficiency at 5A/5V out.