Texas Instruments LM2575S-ADJ-TI

Overview

LM2575S-ADJ-TI from Texas Instruments is a monolithic 1A step-down (buck) switching voltage regulator in TO-263 (DDPAK) package, featuring adjustable output (1.23V–37V), 52 kHz fixed-frequency operation, and integrated thermal shutdown/current limiting. It replaces linear regulators in mid-power DC/DC conversion for industrial power supplies and embedded systems requiring high efficiency and minimal external components.

For engineers reviewing the LM2575S-ADJ-TI datasheet, LM2575S-ADJ-TI pinout, LM2575S-ADJ-TI application, or LM2575S-ADJ-TI equivalent, this page delivers verified technical context, real-world design meaning of key specs, validated pin functions, confirmed alternative parts with functional differences, and supply-chain support details specific to the LM2575S-ADJ-TI variant.

Technical Context

The LM2575S-ADJ-TI implements a current-mode buck topology with internal 52 kHz oscillator, cycle-by-cycle current limiting, and thermal shutdown. Its feedback pin monitors a resistor-divider network to regulate output voltage precisely at 1.23 V reference, enabling programmable outputs from 1.23 V to 37 V across its 40 V input range.

It operates in continuous conduction mode with up to 98% duty cycle, supports TTL-compatible shutdown (50 μA standby), and integrates a 1.4 V (max) saturation switch. Thermal resistance is 37 °C/W (junction-to-ambient) when mounted on ≥1 in² copper area - critical for 1 A load stability without external heatsink.

Key Specifications

Pinout & Package

LM2575S-ADJ-TI uses the 5-lead DDPAK/TO-263 surface-mount package (package code KTT0005B), with exposed thermal pad electrically connected to Pin 2 (Output). Mounting on ≥1 in² copper area achieves θ_JA = 37 °C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM2575T-ADJ-TI, the LM2575S-ADJ-TI offers superior thermal performance in surface-mount layouts, while LM2596S-ADJ-TI provides higher current and precision at the cost of layout requalification - neither is pin-compatible, but both serve overlapping buck-conversion roles with distinct trade-offs.

Availability

LM2575S-ADJ-TI is available at Aetrix Electronics and suitable for industrial power supplies, embedded system pre-regulators, on-card DC/DC converters, and positive-to-negative inverter designs requiring stable component supply, long-lifecycle support, and consistent parametric performance.

Supply support for LM2575S-ADJ-TI 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 ICs, with decades of expertise in switching regulator design and manufacturing reliability.

The LM2575 series was engineered as a robust, easy-to-use replacement for linear regulators in medium-power DC/DC applications - prioritizing simplicity (4 external parts), thermal resilience, and broad input compatibility for industrial and embedded use.

FAQ

What is the maximum input voltage supported by the LM2575S-ADJ-TI?

The LM2575S-ADJ-TI supports a maximum input voltage of 40 V, as specified in its operating ratings. This applies to the standard LM2575 (non-HV) family. Exceeding 40 V risks permanent damage, even briefly - the LM2575HV variant is required for 60 V input applications. The absolute maximum rating is 45 V, but operation above 40 V is not guaranteed or characterized.

How do I set the output voltage for the LM2575S-ADJ-TI?

Set the output voltage of the LM2575S-ADJ-TI using two external resistors (R1 and R2) forming a voltage divider from output to feedback (Pin 4) and ground. The formula is V_OUT = 1.23 V × (1 + R2/R1), with R1 typically 1–5 kΩ. For example, R1 = 2.0 kΩ and R2 = 6.12 kΩ yields 5.0 V. Use 0.1% metal-film resistors for best accuracy and temperature stability.

Does the LM2575S-ADJ-TI require a heatsink in typical operation?

No, the LM2575S-ADJ-TI does not require an external heatsink when mounted on ≥1 in² of 2-oz copper on the PCB - its θ_JA is 37 °C/W under that condition. At 1 A load and 25 °C ambient, junction temperature rise is ~37 °C, well below the 125 °C max operating limit. Heatsinks are unnecessary unless ambient exceeds 85 °C or copper area is reduced.

What type of diode should be used with the LM2575S-ADJ-TI?

A Schottky diode rated for ≥1.2× the output current and ≥1.25× the maximum input voltage is required. For a 1 A, 40 V-input design, a 3 A, 45 V Schottky (e.g., MBR340 or SR104) is recommended. Fast-recovery diodes may be used but increase losses; standard PN diodes are unsuitable due to reverse recovery losses and overheating.

Is the LM2575S-ADJ-TI RoHS compliant and lead-free?

Yes, the LM2575S-ADJ-TI is RoHS compliant and lead-free per TI's official product documentation and packaging markings. It meets JEDEC J-STD-020 moisture sensitivity level (MSL) 3 requirements and is qualified for Pb-free reflow soldering profiles. Always verify the date code and packaging label for the specific reel or tube received.