Texas Instruments LM2675MX-ADJ

Overview

LM2675MX-ADJ from Texas Instruments is a monolithic step-down (buck) DC-DC switching regulator IC with adjustable output voltage (1.21 V to 37 V), 1 A continuous output current capability, 260 kHz fixed-frequency operation, ±1.5% output voltage tolerance over line and load, and 8 V to 40 V input voltage range - used in industrial power supplies, embedded system rails, and point-of-load conversion.

For engineers reviewing the LM2675MX-ADJ datasheet, LM2675MX-ADJ pinout, LM2675MX-ADJ application, or LM2675MX-ADJ equivalent, key selection criteria include feedback reference accuracy (1.21 V), thermal shutdown behavior, ON/OFF control interface compatibility, and external component count minimization for cost-sensitive buck designs.

Technical Context

The LM2675MX-ADJ integrates a DMOS high-side power switch, internal frequency compensation, and a 260 kHz oscillator - eliminating need for external compensation networks. Its feedback loop regulates output by comparing FB pin voltage to an internal 1.21 V reference, requiring only two resistors for output programming.

It operates in continuous conduction mode up to 1 A load, features cycle-by-cycle current limiting (1.25–2.1 A typical), thermal shutdown, and TTL-compatible ON/OFF control with 50 μA standby current - enabling efficient, self-protected regulation without auxiliary circuitry.

Key Specifications

Pinout & Package

LM2675MX-ADJ is packaged in an 8-pin SOIC (D package), 4.9 mm × 6 mm body size, with exposed thermal pad connected internally to GND. Pin functions are validated per TI SNVS129G Rev JUNE 2025.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM2675MX-ADJ, LM2575HVSX-ADJ trades higher input voltage tolerance and lower EMI for reduced efficiency and larger passives, while TPS54202DR offers higher integration and frequency at the cost of increased design complexity and sensitivity to layout parasitics.

Availability

LM2675MX-ADJ is available at Aetrix Electronics and suitable for industrial power supplies, embedded system rails, and point-of-load conversion requiring stable component supply, long-term lifecycle support, and verified thermal performance in 8-pin SOIC packaging.

Supply support for LM2675MX-ADJ 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, embedded processing, and power management technologies, with leadership in high-reliability industrial and automotive-grade components.

The LM2675MX-ADJ belongs to TI's SIMPLE SWITCHER® family - designed specifically for ease-of-use, minimal external component count, and robust operation in cost-sensitive DC-DC conversion applications.

FAQ

What is the minimum input voltage required for stable operation of the LM2675MX-ADJ?

The LM2675MX-ADJ requires a minimum input voltage of 6.5 V under recommended operating conditions. Below this threshold, regulation cannot be maintained - especially when the output voltage is set near the upper end of its 1.21 V to 37 V range. For example, with VOUT = 30 V, VIN must exceed ~32 V to sustain duty cycle margin; always verify minimum VIN using the datasheet's dropout curves (Figure 5-13/5-14) for your specific output setting.

How do I calculate the feedback resistor values for a target output voltage with the LM2675MX-ADJ?

To set VOUT with the LM2675MX-ADJ, use R1 = R2 × ((VOUT / 1.21 V) − 1), where R2 is typically 10 kΩ to 100 kΩ. For example, for 12 V output: R1 = 10 kΩ × ((12 / 1.21) − 1) ≈ 89.2 kΩ - select standard 88.7 kΩ or 90.9 kΩ. The LM2675MX-ADJ's 1.21 V reference has ±1.5% tolerance, so final output accuracy depends on both resistor tolerance and reference drift.

Does the LM2675MX-ADJ require an external catch diode, and what type is recommended?

Yes, the LM2675MX-ADJ requires an external Schottky diode connected from VSW to GND (cathode to VSW). A 3.3 A, 50 V Schottky such as IR 30WQ05F is specified in TI's typical application (Figure 7-1). Fast recovery and low forward voltage (<0.5 V) are essential to maintain efficiency and prevent reverse recovery losses - standard PN diodes are unsuitable due to slow switching and excessive power loss.

Can the LM2675MX-ADJ be used in a synchronous buck configuration?

No, the LM2675MX-ADJ is an asynchronous buck controller with an integrated high-side DMOS switch but no low-side synchronous rectifier. It relies on an external Schottky diode for the freewheeling path. Synchronous operation requires a second actively controlled switch - which the LM2675MX-ADJ does not support. For synchronous alternatives, consider TI's TPS54x02 series or LM2678 family.

What thermal considerations apply to the LM2675MX-ADJ in SOIC (D) package at full 1 A load?

In the 8-pin SOIC package, the LM2675MX-ADJ has a junction-to-ambient thermal resistance (RθJA) of 105°C/W. At 1 A output into 5 V (efficiency ~90%), power dissipation is ~0.56 W - resulting in ~59°C junction rise above ambient. TI states copper PCB traces alone suffice for heatsinking; adding ≥1 in² of 2-oz copper pour under the exposed pad (connected to GND) reduces RθJA significantly and improves reliability under sustained load.