Texas Instruments LMR36006BRNXT

Overview

LMR36006BRNXT from Texas Instruments is a 4.2-V to 60-V, 0.6-A synchronous step-down DC/DC converter in a 2-mm × 3-mm HotRod™ VQFN-HR package. It delivers regulated output voltage via adjustable feedback (V_FB = 1.0 V), operates at 1 MHz fixed frequency, and integrates high-side/low-side MOSFETs with R_DS(on) of 435 mΩ (HS) and 280 mΩ (LS). It supports industrial field transmitters and PLC modules requiring robust 66-V transient tolerance and –40°C to +150°C operation.

For engineers reviewing the LMR36006BRNXT datasheet, LMR36006BRNXT pinout, LMR36006BRNXT application, or LMR36006BRNXT equivalent, key selection criteria include input surge immunity (66 V), ultra-low quiescent current (26 µA), integrated power-good flag with 140-µs deglitch delay, and EMI-optimized HotRod™ layout enabling CISPR 25 Class 5 compliance without external filters.

Technical Context

The LMR36006BRNXT uses peak-current-mode control with internal loop compensation, enabling stable regulation across 4.2–60 V input while automatically transitioning between PWM (heavy load) and PFM (light load) for optimal efficiency. Its valley current limit (0.8–0.95 A LS) and hiccup-mode short-circuit protection (94-ms off-time) provide fault resilience without external circuitry.

It features precision enable thresholds (VEN-VOUT-H = 1.231 V, hysteresis = 110 mV), a 5-V internal LDO (VCC) with 3.8-V UVLO, and a true open-drain power-good flag (PG) referenced to FB with ±7% window and 140-µs filtering-enabling reliable system supervision without external supervisors.

Key Specifications

Pinout & Package

VQFN-HR (12-pin) package with wettable flanks, 0.4-mm pitch, and thermal pad exposed on bottom for enhanced PCB heat dissipation. Designed for minimal EMI layout: VIN and PGND pins are paired on opposite sides; SW and BOOT form tight coupling path; AGND and PGND are separate but require low-inductance connection.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LMR36015BRNXT and LMR33630ADJR, the LMR36006BRNXT offers the smallest solution size for sub-1-A applications at 60-V input, with optimized EMI performance and lowest quiescent current-making it ideal for space- and efficiency-critical field devices where 0.6-A output suffices.

Availability

LMR36006BRNXT is available at Aetrix Electronics and suitable for field transmitters, PLC I/O modules, and HVAC sensor nodes requiring stable component supply across extended temperature and surge-prone environments.

Supply support for LMR36006BRNXT 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 company specializing in analog and embedded processing technologies, with leadership in power management ICs for industrial, automotive, and communications markets.

The LMR36006BRNXT belongs to TI's LMR360xx family of rugged, high-input-voltage buck converters designed specifically for scalable industrial power supplies-emphasizing surge immunity, wide temperature operation, and EMI-compliant integration.

FAQ

What is the maximum input voltage the LMR36006BRNXT can withstand without damage?

The LMR36006BRNXT has an absolute maximum input voltage rating of 66 V, meaning it can survive transient overvoltages up to that level without permanent damage. Its recommended operating input range is 4.2 V to 60 V. This 66-V tolerance enables robust operation in industrial environments subject to IEC 61000-4-5 surge events, eliminating the need for external TVS diodes in many designs. The LMR36006BRNXT maintains regulation throughout its full 4.2–60-V operating range.

Does the LMR36006BRNXT support adjustable output voltage, and how is it configured?

Yes, the LMR36006BRNXT supports fully adjustable output voltage via an external resistor divider connected to the FB pin. Its internal reference is precisely trimmed to 1.0 V (±1.5%), so V_OUT = 1.0 V × (1 + R_FBT/R_FBB). Common configurations include 3.3 V (R_FBT = 232 kΩ, R_FBB = 100 kΩ) and 5.0 V (R_FBT = 402 kΩ, R_FBB = 100 kΩ). The FB pin must never be left floating or grounded, and the divider should use 1% tolerance resistors for best accuracy. This flexibility makes the LMR36006BRNXT suitable for diverse system rails.

How does the power-good (PG) flag on the LMR36006BRNXT behave during startup and fault conditions?

The LMR36006BRNXT PG pin is an open-drain output that goes high only when V_OUT is within ±7% of the target (e.g., 3.09–3.51 V for 3.3 V). During startup, it asserts high after a typical 4-ms delay following EN assertion. It deasserts low during undervoltage, overcurrent, thermal shutdown, or EN deactivation. A built-in 140-µs deglitch filter prevents false triggering from brief transients. When unused, PG must be grounded-not left floating-to ensure predictable system behavior. This eliminates external supervision circuitry in most applications.

What thermal performance can be expected from the LMR36006BRNXT in a typical 2-layer PCB layout?

In a standard 2-layer PCB with 1-oz copper, 200 mm² thermal pad copper pour, and no airflow, the LMR36006BRNXT exhibits a junction-to-board thermal resistance (R_θJB) of 23.3°C/W. At 0.6-A load and 24-V input, power dissipation is ~0.3 W, resulting in ~7°C rise above board temperature. With proper thermal vias under the exposed pad and modest airflow, junction temperatures remain well below the 150°C maximum even at full load and 85°C ambient-enabling reliable operation in sealed enclosures. Thermal shutdown activates only above 170°C.

Is the LMR36006BRNXT pin-compatible with other devices in the LMR360xx family?

Yes, the LMR36006BRNXT shares the same 12-pin VQFN-HR (2 mm × 3 mm) package and pinout with the LMR36015BRNXT (1.5-A version) and LMR36006CRNXT (2.1-MHz version). This enables direct hardware reuse across designs requiring different current ratings or switching frequencies-reducing layout effort and qualification time. No PCB changes are needed when upgrading to LMR36015BRNXT for higher current, or switching to LMR36006CRNXT for faster transient response and smaller inductors.