Texas Instruments LMR23630FDRRT

Overview

LMR23630FDRRT from Texas Instruments is a 36-V, 3-A synchronous step-down DC-DC converter in a 12-pin WSON package with wettable flanks, featuring adjustable switching frequency (200–2200 kHz), FPWM mode for low ripple, 75-µA quiescent current in PFM, and integrated high- and low-side MOSFETs with R_DS(on) of 160 mΩ/95 mΩ. It delivers stable 1–28 V output for industrial power conditioning from unregulated sources.

For engineers reviewing the LMR23630FDRRT datasheet, LMR23630FDRRT pinout, LMR23630FDRRT application, or LMR23630FDRRT equivalent, key selection considerations include its RT-pin-based frequency adjustability, FPWM vs PFM mode trade-offs, thermal performance in compact WSON layout, and compatibility with prebiased soft-start and precision enable sequencing in PLC and HVAC control systems.

Technical Context

The LMR23630FDRRT implements peak-current-mode control with internal compensation, enabling stable regulation across wide input (4–36 V) and output (1–28 V) ranges without external loop components. Its 60 ns minimum on-time supports high-duty-cycle operation down to 1.5 V output at 36 V input.

It features dual operating modes: PFM for ultra-low IQ (75 µA) at light load and FPWM for fixed-frequency, low-ripple performance. Frequency synchronization (200–2200 kHz) and RT-pin programmability allow EMI optimization, while hiccup-mode short-circuit protection and thermal shutdown ensure robustness in factory automation environments.

Key Specifications

Pinout & Package

The LMR23630FDRRT uses a 12-pin WSON package (3.00 mm × 3.00 mm) with wettable flanks for automated optical inspection and enhanced thermal dissipation via exposed thermal pad connected to PGND.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LMR23630FDRRT, LMR23630DRR trades PGOOD functionality for identical frequency flexibility, while LMR23625FDDA offers pin-count reduction and fixed-frequency simplicity at the expense of current headroom and feature set - making LMR23630FDRRT optimal for designs requiring both programmable frequency and power-good signaling in minimal area.

Availability

LMR23630FDRRT is available at Aetrix Electronics and suitable for factory automation systems, HVAC control units, and industrial asset trackers requiring stable component supply, long-lifecycle support, and consistent parametric performance across production batches.

Supply support for LMR23630FDRRT 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 and automotive markets.

The LMR23630FDRRT belongs to TI's SIMPLE SWITCHER® family, designed specifically for rugged, easy-to-use DC-DC conversion in harsh industrial environments where reliability, wide input range, and minimal external components are critical.

FAQ

What is the function of the RT pin on the LMR23630FDRRT?

The RT pin on the LMR23630FDRRT sets the switching frequency by connecting an external resistor to AGND. With RT open, the device defaults to 400 kHz; using resistors from 17.8 kΩ to 198 kΩ adjusts frequency from 2200 kHz down to 200 kHz. This pin is not intended to be shorted to ground, and its impedance directly determines oscillator timing - enabling EMI mitigation and inductor size optimization in the final LMR23630FDRRT design.

Does the LMR23630FDRRT support synchronization to an external clock?

Yes, the LMR23630FDRRT supports frequency synchronization via its EN/SYNC pin. An AC-coupled external clock signal (200–2200 kHz, 2.8–5.5 V amplitude) can be injected through a small capacitor to align switching edges with system clocks or other converters. This capability reduces beat frequencies and simplifies EMI filtering in multi-rail LMR23630FDRRT-based power systems used in PLCs and motion controllers.

How does the PGOOD pin on the LMR23630FDRRT operate?

The PGOOD pin on the LMR23630FDRRT is an open-drain output that asserts low when output voltage deviates beyond ±7% of the target (e.g., 92–107% of V_REF). It features deglitch delays of 150 µs (rise) and 18 µs (fall) to reject transients. A 10–100 kΩ pullup to ≤12 V is required. This signal enables safe power sequencing and fault detection in LMR23630FDRRT-powered systems like HVAC controllers where rail integrity must be verified before firmware initialization.

Can the LMR23630FDRRT start up into a prebiased output?

Yes, the LMR23630FDRRT supports soft-start into a prebiased output. Its internal soft-start circuitry monitors the FB pin voltage during startup and modulates the duty cycle to prevent reverse current flow or output overshoot when powering into an already charged rail. This behavior is critical in redundant power architectures and hot-swap applications where the LMR23630FDRRT may be inserted into a live system - ensuring seamless transition without disrupting downstream logic.

What thermal performance can be expected from the LMR23630FDRRT in its WSON package?

The LMR23630FDRRT in the 12-pin WSON package has a junction-to-board thermal resistance (R_θJB) of 16.3 °C/W and junction-to-ambient (R_θJA) of 41.5 °C/W with standard 2-layer PCB layout. With proper thermal pad soldering to a solid ground plane, it sustains 3-A continuous output at ambient temperatures up to +85°C without derating. The exposed thermal pad (Pin 9) must be connected to PGND and routed with ≥4 thermal vias to inner ground layers to achieve rated performance in the final LMR23630FDRRT implementation.