Texas Instruments LM22671QMRX-5.0/NOPB

Overview

LM22671QMRX-5.0/NOPB from Texas Instruments is a 42 V, 500 mA synchronous step-down DC/DC regulator with fixed 5.0 V output, 500 kHz switching frequency, ±1.5% feedback reference accuracy, and integrated 200 mΩ N-channel MOSFET. It operates from 4.5 V to 42 V input and supports industrial embedded power rails requiring stable 5 V supply under wide temperature range.

For engineers reviewing the LM22671QMRX-5.0/NOPB datasheet, LM22671QMRX-5.0/NOPB pinout, LM22671QMRX-5.0/NOPB application, or LM22671QMRX-5.0/NOPB equivalent, key selection criteria include input voltage range (4.5–42 V), thermal shutdown threshold (150°C), soft-start current (50 µA typ), enable threshold hysteresis (0.6 V), and SO PowerPAD™ package compatibility with PCB thermal management.

Technical Context

The LM22671QMRX-5.0/NOPB implements voltage-mode PWM control with input voltage feed-forward for loop gain stabilization across input variations. Its internal Type III compensation is optimized for fixed 5 V output, eliminating external compensation components.

It integrates a bootstrap gate driver with dedicated BOOT/SW pins to drive the high-side MOSFET, requires ≥5 mA minimum load for boot-cap recharge during minimum off-time (100 ns), and supports three RT/SYNC modes: internal 500 kHz oscillator, resistor-adjustable 200–1000 kHz, or external synchronization (1–1 MHz).

Key Specifications

Pinout & Package

LM22671QMRX-5.0/NOPB uses an HSOP-8 package (4.89 mm × 3.90 mm) with exposed thermal pad (EP) that must be soldered to PCB ground for thermal performance and EMI reduction.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM22671QMRX-5.0/NOPB, LM22670QMRX-5.0/NOPB offers lower input capability but insufficient current headroom, while TPS54302DDAR delivers higher current but lacks fixed 5 V output and requires full schematic redesign - neither is pin-compatible, and both necessitate layout and firmware validation for replacement.

Availability

LM22671QMRX-5.0/NOPB is available at Aetrix Electronics and suitable for industrial control PLCs, automotive body electronics, and telecom remote radio units requiring stable component supply across extended temperature and voltage ranges.

Supply support for LM22671QMRX-5.0/NOPB 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 over 90 years of innovation history.

The LM22671 product line delivers SIMPLE SWITCHER® buck regulators targeting cost-sensitive, space-constrained industrial and automotive power conversion where ease of design-in and thermal robustness are critical.

FAQ

What is the maximum input voltage rating for LM22671QMRX-5.0/NOPB?

The absolute maximum input voltage for LM22671QMRX-5.0/NOPB is 43 V, but the recommended operating range is 4.5 V to 42 V. Operation above 42 V risks exceeding safe junction temperature or violating internal device stress limits, even briefly. The 42 V upper limit ensures reliable long-term performance under transient conditions such as load dump in automotive applications. Always maintain ≥1 V margin below 43 V in system design.

Does LM22671QMRX-5.0/NOPB require external feedback resistors?

No, LM22671QMRX-5.0/NOPB does not require external feedback resistors. It features an internally trimmed 5.0 V reference connected directly to the FB pin, enabling true fixed-output operation. Unlike the LM22671-ADJ variant, this part has no external resistor divider network - the FB pin is left unconnected in standard operation. This simplifies layout, improves accuracy, and eliminates resistor tolerance drift from the output regulation path.

Can LM22671QMRX-5.0/NOPB synchronize to an external clock?

Yes, LM22671QMRX-5.0/NOPB supports external clock synchronization via the RT/SYNC pin. When driven with a clean 1–1 MHz square wave meeting VSYNC = 1.75 V threshold and 50% duty cycle, the device locks to the rising edge of the external signal. Synchronization must be established during startup; loss of clock causes automatic fallback to the internal 500 kHz oscillator. Note: current limit foldback is disabled during sync mode, requiring careful short-circuit protection design.

What thermal pad connection is required for LM22671QMRX-5.0/NOPB?

The exposed thermal pad (EP) on LM22671QMRX-5.0/NOPB must be soldered directly to a solid PCB ground plane using ≥4 thermal vias (0.3 mm diameter) spaced evenly beneath the pad. TI specifies R_θJA = 60°C/W only when EP is properly connected; floating or undersized thermal land increases junction temperature by >30°C at full load. No thermal compound or isolation is permitted - the pad is electrically GND and serves dual mechanical and thermal functions.

Is LM22671QMRX-5.0/NOPB qualified for automotive applications?

Yes, LM22671QMRX-5.0/NOPB is the automotive-grade variant (LM22671-Q1 family) and is AEC-Q100 Grade 1 qualified for operation from –40°C to +125°C junction temperature. It undergoes additional stress testing including HTOL, temperature cycling, and ESD per JS-001. The "Q" suffix and "/NOPB" lead-free marking confirm automotive qualification - standard LM22671 parts lack this certification and are not approved for vehicle ECUs or body control modules.