Texas Instruments LM22673MRX-5.0/NOPB

Overview

LM22673MRX-5.0/NOPB from Texas Instruments is a 42 V input, 3 A synchronous step-down DC/DC regulator with fixed 5.0 V output, 500 kHz switching frequency, ±1.5% feedback reference accuracy, and integrated 120 mΩ N-channel MOSFET in HSOP-8 PowerPAD package. It delivers high efficiency (>90%) in industrial power rails converting 12 V or 24 V inputs to stable 5 V for microcontroller cores and peripheral logic.

For engineers reviewing the LM22673MRX-5.0/NOPB datasheet, LM22673MRX-5.0/NOPB pinout, LM22673MRX-5.0/NOPB application, or LM22673MRX-5.0/NOPB equivalent, key selection considerations include its 4.5–42 V wide input range, adjustable current limit via IADJ pin, internal voltage-mode compensation, soft-start control via external capacitor, and thermal shutdown at 150°C junction temperature.

Technical Context

The LM22673MRX-5.0/NOPB implements a voltage-mode PWM controller with input voltage feedforward to stabilize loop gain 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 N-channel MOSFET, requiring a 10 nF ceramic capacitor between BOOT and SW. Minimum on-time (100 ns) and off-time (200 ns) constrain practical VIN/VOUT ratios and enforce minimum load (~5 mA) for bootstrap recharge.

Key Specifications

Pinout & Package

LM22673MRX-5.0/NOPB uses an HSOP-8 PowerPAD (exposed pad) package measuring 4.89 mm × 3.90 mm. The exposed thermal pad must be soldered to a PCB ground plane for thermal management and electrical stability.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM22673MRX-5.0/NOPB, LM22674MRX-5.0/NOPB trades 0.5 A current capacity for higher switching frequency and lower conduction loss, while TPS54340DDAR adds configurability at the cost of increased external component count and design complexity.

Availability

LM22673MRX-5.0/NOPB is available at Aetrix Electronics and suitable for industrial control, telecom power conversion, and automotive body electronics requiring stable component supply across long production lifecycles.

Supply support for LM22673MRX-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 delivering analog, embedded processing, and connectivity solutions for industrial, automotive, and communications markets.

The LM22673 product line delivers SIMPLE SWITCHER® buck regulators targeting high-voltage, medium-current DC/DC conversion where ease of design, thermal robustness, and wide input range are critical.

FAQ

What is the maximum input voltage rating for LM22673MRX-5.0/NOPB?

The absolute maximum input voltage for LM22673MRX-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 operating area limits and may trigger overvoltage protection or cause permanent damage. Designers should maintain at least 1 V margin below 43 V in worst-case transient conditions such as load dump in automotive applications.

Does LM22673MRX-5.0/NOPB require an external feedback resistor divider?

No, LM22673MRX-5.0/NOPB does not require an external feedback resistor divider because it features a factory-trimmed internal 5.0 V reference with ±1.5% accuracy. The FB pin is internally connected to the output, enabling true fixed-output operation. This eliminates resistor tolerance errors, layout sensitivity, and board space typically needed for adjustable versions like LM22673-ADJ.

How is current limit adjusted on LM22673MRX-5.0/NOPB?

Current limit on LM22673MRX-5.0/NOPB is adjusted using a single resistor between the IADJ pin and GND. With no resistor, the default peak switch current is 4.2 A (typ). Adding a resistor sets the limit per Figure 12 in the datasheet, with accuracy of +35% / –25%. For example, a 10 kΩ resistor reduces the limit to approximately 2.5 A. The adjustment occurs once at startup and remains fixed until power cycle.

What thermal management is required for LM22673MRX-5.0/NOPB in continuous 3 A operation?

For continuous 3 A operation, LM22673MRX-5.0/NOPB requires the exposed thermal pad (EP) to be soldered to a minimum 200 mm² copper pour connected to GND. With this layout, junction-to-ambient thermal resistance is 60°C/W (HSOP-8), allowing ~2.5 W power dissipation before reaching 125°C junction temperature at 25°C ambient. Forced air or additional thermal vias improve margin in enclosed environments.

Can LM22673MRX-5.0/NOPB be synchronized to an external clock?

No, LM22673MRX-5.0/NOPB does not support external clock synchronization. It operates at a fixed 500 kHz internal oscillator frequency with no RT/SYNC pin. For designs requiring frequency alignment-such as noise-sensitive audio or multi-rail systems-alternatives like TPS54340DDAR (with SYNC pin) or LM5115 (external sync capable) must be considered instead of LM22673MRX-5.0/NOPB.