Texas Instruments LM2575T-12-TI

Overview

LM2575T-12-TI from Texas Instruments is a monolithic 1A step-down (buck) switching voltage regulator in TO-220 package, delivering a fixed 12V output with ±4% tolerance over 15–40V input and 0.2–1A load. It integrates PWM controller, power switch, oscillator, and protection circuitry, enabling high-efficiency DC/DC conversion without external compensation. It replaces linear regulators in industrial power supplies requiring compact, thermally robust 12V rails.

For engineers reviewing the LM2575T-12-TI datasheet, LM2575T-12-TI pinout, LM2575T-12-TI application, or LM2575T-12-TI equivalent, key selection criteria include its 52 kHz fixed-frequency operation, internal thermal shutdown and cycle-by-cycle current limiting, TTL-compatible shutdown capability (50 μA standby), and compatibility with standard off-the-shelf inductors - all critical for reliable, low-BOM-count buck converter design.

Technical Context

The LM2575T-12-TI implements a current-mode controlled buck topology with an integrated 65 V N-channel DMOS power switch and 52 kHz oscillator. Its feedback loop uses a precision 1.23V reference and internal error amplifier to regulate output voltage via duty-cycle adjustment.

Protection features include thermal shutdown triggered at 150°C junction temperature and peak-current limiting set at 2.2A typical (1.7–3.2A range). The device operates across −40°C to +125°C junction temperature and supports input voltages up to 40V, with dropout behavior defined by minimum on-time and saturation voltage (0.9V typical at 1A).

Key Specifications

Pinout & Package

LM2575T-12-TI is housed in a 5-lead TO-220 package (package code NDH0005D) with exposed tab electrically connected to Pin 2 (Output). Mounting requires thermal interface to heatsink or copper pour.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM2575HVT-12, LM2575T-12-TI trades input voltage headroom for cost and legacy compatibility; compared with LM2596T-12, it offers proven reliability and simpler magnetics design at the expense of current rating and switching frequency - making it optimal for established 1A, 40V-max industrial platforms.

Availability

LM2575T-12-TI is available at Aetrix Electronics and suitable for industrial power supplies, embedded system pre-regulators, on-card DC/DC conversion, and positive-to-negative converter designs requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for LM2575T-12-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.

The LM2575 series was developed as part of TI's SIMPLE SWITCHER® portfolio to provide rugged, easy-to-use buck regulators for industrial and embedded applications where reliability, thermal resilience, and minimal external component count are critical.

FAQ

What is the maximum input voltage rating for LM2575T-12-TI?

The LM2575T-12-TI has a maximum input voltage rating of 40V, as specified in the Absolute Maximum Ratings table. Operation above this level risks permanent damage. For applications requiring higher input voltage tolerance (e.g., 48V systems), the pin-compatible LM2575HVT-12 variant - rated for up to 60V - should be considered instead of LM2575T-12-TI.

Does LM2575T-12-TI require external compensation components?

No, LM2575T-12-TI includes internal frequency compensation and is designed for stable operation with only four external components: input capacitor, output capacitor, inductor, and catch diode. This eliminates the need for external compensation networks, simplifying design and reducing bill-of-materials cost - a core advantage of the LM2575T-12-TI architecture.

What is the thermal performance of LM2575T-12-TI in a TO-220 package without a heatsink?

In the standard 5-lead TO-220 package (NDH0005D), LM2575T-12-TI has a junction-to-ambient thermal resistance (θJA) of 65°C/W with minimal copper area. At 1A output and 15V input, typical power dissipation is ~3W, resulting in ~195°C junction rise - exceeding the 125°C max operating temperature. Therefore, LM2575T-12-TI requires either a heatsink or ≥4 in² PCB copper area (θJA = 45°C/W) for full-load operation.

Can LM2575T-12-TI be used in a buck-boost (inverting) configuration?

Yes, LM2575T-12-TI can be configured as a positive-to-negative converter using the standard buck-boost topology, as documented in TI's application notes and the LM2575 datasheet Figure 1. In this mode, the output is inverted, and the feedback network must be reconfigured to sense the negative rail - enabling LM2575T-12-TI to generate −12V from a +24V input.

What is the shutdown current consumption of LM2575T-12-TI?

The LM2575T-12-TI draws 50 μA typical (max 500 μA) quiescent current in TTL shutdown mode when the ON/OFF pin is held high (>2.2V). This ultra-low standby current makes LM2575T-12-TI suitable for battery-powered or energy-sensitive systems where power sequencing and sleep-mode integrity are essential design requirements.