Texas Instruments LMR51410XDBVR

Overview

LMR51410XDBVR from Texas Instruments is a synchronous buck DC/DC converter delivering 1A continuous output current, operating from 4V to 42V input, with fixed 400kHz switching frequency and PFM light-load mode - designed for rugged industrial power conditioning in PLCs, smart meters, and major appliances.

For engineers reviewing the LMR51410XDBVR datasheet, LMR51410XDBVR pinout, LMR51410XDBVR application, or LMR51410XDBVR equivalent, key selection considerations include its SOT-23-6 package footprint, ±1.5% reference voltage accuracy, 80ns minimum on-time, hiccup-mode short-circuit protection, and monotonic start-up with prebiased output capability.

Technical Context

The LMR51410XDBVR implements fixed-frequency peak-current mode control with internal compensation, enabling stable regulation using minimal external components. It integrates synchronous high-side (0.7Ω R_DS(on)) and low-side (0.36Ω R_DS(on)) MOSFETs, supports adjustable output voltage via 0.8V reference, and features precision enable with 1.227V turn-on threshold.

Its PFM operation optimizes light-load efficiency, while built-in protections include cycle-by-cycle current limiting (1.25–1.95A high-side peak), thermal shutdown at 165°C, VIN UVLO with 4V rising threshold and 0.25V hysteresis, and hiccup-mode recovery after sustained short circuits.

Key Specifications

Pinout & Package

SOT-23-6 (DBV) package: 2.90mm × 2.80mm footprint, thermally enhanced for 1A operation in space-constrained industrial PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LMR51410XDBVR, the XFDBVR variant trades light-load efficiency for tighter ripple control, while the LMR51610XDBVR offers higher current at the cost of reduced high-VIN step-down capability - both require validation of thermal performance and feedback loop stability in the target design.

Availability

LMR51410XDBVR is available at Aetrix Electronics and suitable for PLC power supplies, smart meter DC-DC stages, and major appliance control boards requiring stable component supply, long-term industrial lifecycle support, and consistent parametric performance.

Supply support for LMR51410XDBVR 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 industrial-grade product development and manufacturing excellence.

The LMR514xx family targets rugged, space-constrained industrial power conversion - delivering high-voltage tolerance, integrated protection, and simplified design for PLCs, energy meters, and factory automation equipment.

FAQ

What is the maximum input voltage transient the LMR51410XDBVR can withstand?

The LMR51410XDBVR supports input transients up to 50V for durations under 10ns, as specified in its Absolute Maximum Ratings. This capability enables reliable operation in industrial environments with load dump or inductive switching spikes, without requiring external TVS clamping in many cases. The device's internal circuitry is hardened to sustain these brief overvoltage events without latch-up or degradation. Always verify system-level stress with worst-case transient waveforms in your application.

Does the LMR51410XDBVR require an external bootstrap capacitor?

Yes, the LMR51410XDBVR requires a 100nF ceramic capacitor (X7R/X5R, ≥16V rating) between the CB and SW pins to generate gate drive voltage for its integrated high-side MOSFET. This bootstrap capacitor is refreshed during each low-side conduction phase. Omitting or undersizing this capacitor causes high-side drive failure and immediate regulation loss. TI specifies placement directly between CB and SW with minimal trace length to maintain stability and efficiency.

Can the LMR51410XDBVR operate with a prebiased output?

Yes, the LMR51410XDBVR features monotonic start-up with prebiased output support - it will not force reverse current into a precharged output rail. This behavior is enabled by internal circuitry that monitors FB voltage during enable and adjusts soft-start accordingly. It is essential for applications involving hot-swap, power sequencing, or backup battery switchover where the output may already be held at nominal voltage before the converter starts.

What is the purpose of the EN pin's precision enable function in the LMR51410XDBVR?

The EN pin on the LMR51410XDBVR provides a precision enable threshold (1.227V typical) that allows designers to implement system-level undervoltage lockout (UVLO) using an external resistor divider from VIN. This enables controlled startup only when input voltage exceeds a defined safe level - critical for battery-powered or utility-fed systems where brownout operation must be avoided. The EN pin must never be left floating and draws only 10–50nA when active.

How does hiccup-mode protection work in the LMR51410XDBVR during a short circuit?

Under sustained short-circuit conditions, the LMR51410XDBVR enters hiccup mode after detecting 256 consecutive current-limit cycles: it shuts down for 150ms (typical THICCUP), then attempts automatic restart. This cycle repeats until the fault clears. Hiccup mode limits average power dissipation to prevent thermal damage - unlike continuous current limiting, which would cause rapid junction temperature rise. It also aids fault diagnosis by producing observable on/off pulsing at the output.