Texas Instruments LM22673MRE-ADJ/NOPB

Overview

LM22673MRE-ADJ/NOPB from Texas Instruments is a 42 V, 3 A step-down DC/DC voltage regulator in an HSOP-8 PowerPAD package, featuring adjustable output (as low as 1.285 V), 500 kHz fixed switching frequency, and internal voltage-mode compensation. It integrates a 120 mΩ N-channel MOSFET switch and supports industrial control, telecom power, and embedded systems requiring robust 24 V/12 V rail conversion.

For engineers reviewing the LM22673MRE-ADJ/NOPB datasheet, LM22673MRE-ADJ/NOPB pinout, LM22673MRE-ADJ/NOPB application, or LM22673MRE-ADJ/NOPB equivalent, key selection criteria include input voltage range (4.5–42 V), feedback reference accuracy (±1.5%), soft-start programmability, adjustable current limit via IADJ pin, and thermal shutdown at 150°C.

Technical Context

The LM22673MRE-ADJ/NOPB implements a voltage-mode PWM controller with input voltage feedforward to stabilize loop gain across wide VIN variations. Its internal Type III compensation is optimized for output voltages ≤5 V, enabling stable operation with low-ESR ceramic capacitors without external compensation components.

It features a bootstrap gate driver for the high-side N-MOSFET, requiring a 10 nF ceramic capacitor between BOOT and SW pins. Minimum on-time (100 ns) and off-time (200 ns) constrain duty-cycle limits, supporting high VIN-to-VOUT ratios while ensuring boot-capacitor recharge and accurate current-sense timing.

Key Specifications

Pinout & Package

LM22673MRE-ADJ/NOPB uses the HSOP-8 PowerPAD (DDA) package with exposed thermal pad soldered to PCB ground plane for enhanced thermal performance (R_θJA = 60°C/W). The 4.89 mm × 3.90 mm body size supports high-density layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM22670MRE-ADJ/NOPB, the LM22673MRE-ADJ/NOPB offers higher input voltage capability and faster transient response due to 500 kHz operation; versus TPS54332DR, it provides superior design flexibility through IADJ and SS pin control, at the expense of slightly higher R_DS(ON).

Availability

LM22673MRE-ADJ/NOPB is available at Aetrix Electronics and suitable for industrial motor drives, telecom power supplies, and embedded computing systems requiring stable component supply across multi-year production cycles.

Supply support for LM22673MRE-ADJ/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 decades of expertise in high-reliability DC/DC conversion.

The LM22673 product line delivers SIMPLE SWITCHER® buck regulators targeting industrial, telecom, and embedded applications needing wide-input, high-current, easy-to-design power solutions - emphasizing minimal external components and WEBENCH® integration.

FAQ

What is the minimum output voltage achievable with LM22673MRE-ADJ/NOPB?

The LM22673MRE-ADJ/NOPB has a feedback reference voltage of 1.285 V (typical), which sets the lowest possible output voltage when the FB pin is connected directly to VOUT. With an external resistor divider, outputs as low as 1.285 V can be precisely set - no lower output is supported, as the internal reference cannot be scaled below this value. This makes LM22673MRE-ADJ/NOPB suitable for powering modern low-voltage cores like 1.2 V or 1.8 V devices only when paired with appropriate divider ratios and layout attention to noise rejection at the FB node.

Does LM22673MRE-ADJ/NOPB require an external bootstrap diode?

No, LM22673MRE-ADJ/NOPB integrates a bootstrap diode internally, eliminating the need for an external component between BOOT and VIN. This simplifies the bill of materials and improves reliability by removing a potential failure point. However, a 10 nF ceramic capacitor must still be placed between BOOT and SW pins to provide the floating gate-drive voltage for the high-side N-MOSFET - this capacitor must be mounted with short, low-inductance traces to ensure proper gate charging during each switching cycle.

How is current limit adjusted on LM22673MRE-ADJ/NOPB?

Current limit on LM22673MRE-ADJ/NOPB is adjusted using a single resistor connected between the IADJ pin and GND. During startup, the IC samples the IADJ voltage after ~100 µs: if above ~0.8 V (e.g., pin left open), it defaults to 4.2 A (typ); if held at 0.8 V via resistor, the resulting current sets the limit per Figure 12 in the datasheet. Resistor values from 10 kΩ to 100 kΩ yield limits from ~3.4 A to ~5.5 A. Accuracy degrades to +35%/–25% when adjusted, so LM22673MRE-ADJ/NOPB is best used where moderate tolerance is acceptable.

What thermal considerations apply to LM22673MRE-ADJ/NOPB in HSOP-8 PowerPAD package?

LM22673MRE-ADJ/NOPB in HSOP-8 PowerPAD (DDA) has a junction-to-ambient thermal resistance (R_θJA) of 60°C/W with standard 2-layer PCB layout. To maintain safe operation at 3 A, the exposed pad must be soldered to a minimum 1-inch² copper area tied to GND - this reduces thermal resistance significantly. Internal thermal shutdown activates at ~150°C junction temperature and releases at ~135°C. For continuous 3 A operation at 42 V input, forced airflow or additional copper pours are recommended to avoid thermal limiting, especially in enclosed enclosures.

Can LM22673MRE-ADJ/NOPB be synchronized to an external clock?

No, LM22673MRE-ADJ/NOPB does not support external synchronization. It operates at a fixed 500 kHz internal oscillator frequency with no RT/SYNC pin or frequency-adjust capability. This differs from later-generation regulators like the LM5164 or TPS54332, which offer sync inputs. For noise-sensitive applications requiring frequency alignment, designers must rely on careful layout, filtering, or accept the fixed 500 kHz fundamental and its harmonics - or select an alternative part with sync functionality.