Texas Instruments LMR38010SDDAR

Overview

LMR38010SDDAR from Texas Instruments is a 4.2-V to 80-V, 1-A synchronous buck DC/DC converter with 40-µA quiescent current, precision enable, and integrated synchronous rectification in an 8-pin HSOIC PowerPAD package. It delivers regulated output for industrial transport and MHEV/EV systems requiring wide-input resilience and pre-biased start-up capability.

For engineers reviewing the LMR38010SDDAR datasheet, LMR38010SDDAR pinout, LMR38010SDDAR application, or LMR38010SDDAR equivalent, key selection factors include its 200-kHz–2.2-MHz adjustable switching frequency, spread-spectrum EMI reduction, ±1.0% reference voltage tolerance at 25°C, and functional safety documentation support.

Technical Context

The LMR38010SDDAR employs fixed-frequency peak-current mode control with internal compensation, enabling stable regulation across input voltages from 4.2 V to 80 V and output loads up to 1 A. Its architecture integrates high-side (303 mΩ) and low-side (133 mΩ) MOSFETs, supports PFM and FPWM operation modes, and features cycle-by-cycle current limiting with hiccup-mode short-circuit protection.

It implements precision enable logic (VEN-H = 1.25 V typ), a filtered open-drain power-good flag with 40-µs glitch filter, and RT/SYNC pin dual functionality-resistor-programmable frequency (200 kHz–2.2 MHz) or external clock synchronization (300 kHz–2.1 MHz). Thermal shutdown activates at 163°C with 13°C hysteresis.

Key Specifications

Pinout & Package

LMR38010SDDAR is housed in an 8-pin HSOIC (DDA) package with exposed thermal pad (PowerPAD™), measuring 4.89 mm × 3.90 mm. The package supports high-power dissipation with R_θJA = 42.9°C/W and R_θJC(bot) = 4.3°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LMR38010FDDAR and LMR38010FSDDAR, the LMR38010SDDAR uniquely balances ultra-low quiescent current (40 µA) with spread-spectrum EMI reduction-making it optimal for battery-backed industrial IoT nodes where standby life and EMC certification are co-prioritized.

Availability

LMR38010SDDAR 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 LMR38010SDDAR 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 decades of expertise in high-reliability industrial and automotive power conversion.

The LMR38010SDDAR belongs to TI's SIMPLE SWITCHER® family-designed specifically for rugged, wide-input industrial and transportation power systems where input transients, thermal stress, and long product lifecycles are primary constraints.

FAQ

What is the minimum input voltage required for LMR38010SDDAR to start up and maintain regulation?

The LMR38010SDDAR requires a minimum input voltage of 4.2 V to initiate start-up and sustain regulation. During deep input dips, it achieves nearly 100% duty cycle to maintain output voltage-making it suitable for cold-crank scenarios in 12-V automotive and MHEV systems. Below 4.2 V, the device enters undervoltage lockout and ceases switching. This threshold is specified across the full –40°C to +150°C junction temperature range.

Does LMR38010SDDAR support synchronization to an external clock, and what are the valid frequency and voltage requirements?

Yes, the LMR38010SDDAR supports external clock synchronization via the RT/SYNC pin. Valid synchronization frequencies range from 300 kHz to 2.1 MHz. The external clock must have a high-level voltage ≥2.0 V, low-level voltage ≤0.6 V, and pulse width ≥50 ns. The internal PLL locks to the falling edge of the input clock, and if the clock stops, the device automatically reverts to resistor-programmed operation. This capability is confirmed in the Electrical Characteristics table under "SYNC clock high/low level thresholds" and "Clock lock time."

How does the power-good (PG) flag on LMR38010SDDAR behave during start-up and fault conditions?

The PG pin on LMR38010SDDAR is an open-drain output that pulls low during start-up (for ~4 ms after EN assertion), thermal shutdown, current-limit hiccup, or output undervoltage/overvoltage faults. It remains high only when V_OUT is within 92–112% of the target (based on FB reference), with built-in 40-µs glitch filtering to ignore transient excursions. When EN is low, PG is forced low regardless of output status. These behaviors are documented in Section 7.5 under "Power-Good" parameters and Figure 8-6.

Can LMR38010SDDAR operate with a pre-charged output voltage, and how is this enabled?

Yes, the LMR38010SDDAR supports start-up with a pre-biased output-a feature explicitly listed in its Features section and verified in the Description. This is achieved through internal circuitry that prevents reverse current flow during initial switch turn-on, allowing safe ramp-up even when V_OUT is already at or near the target voltage. No external components or configuration changes are required; the function is inherent to the IC's control architecture and validated across the full operating temperature range.

What thermal performance metrics are specified for LMR38010SDDAR in its HSOIC PowerPAD package?

The LMR38010SDDAR in the DDA (HSOIC-8) PowerPAD package has a junction-to-ambient thermal resistance (R_θJA) of 42.9°C/W on a standard 2-layer board, and 29°C/W on TI's evaluation module board. Its junction-to-case (bottom) resistance is 4.3°C/W, confirming efficient heat transfer to the PCB ground plane. Thermal shutdown activates at 163°C with 13°C hysteresis (recovery at 150°C), and these values are production-tested per JEDEC JESD51 standards and published in Section 7.4 of the datasheet.