Texas Instruments LM2575T-5.0/LB03

Overview

LM2575T-5.0/LB03 from Texas Instruments is a monolithic 1A step-down (buck) switching voltage regulator in a 5-lead TO-220 package, delivering a fixed 5.0V ±4% output across 8V–40V input, with 52 kHz fixed-frequency operation, thermal shutdown, and cycle-by-cycle current limiting. It replaces linear regulators in industrial power supplies requiring high efficiency and minimal external components.

For engineers reviewing the LM2575T-5.0/LB03 datasheet, LM2575T-5.0/LB03 pinout, LM2575T-5.0/LB03 application, or LM2575T-5.0/LB03 equivalent, key selection criteria include its 1A continuous output capability, 77% typical efficiency at 12V_IN/1A, TO-220 thermal resistance (θ_JA = 65°C/W unheatsinked), TTL-compatible shutdown, and compatibility with standard off-the-shelf inductors.

Technical Context

The LM2575T-5.0/LB03 integrates a PWM controller, power switch, oscillator, error amplifier, and protection circuitry into a single silicon die. Its internal 52 kHz oscillator drives a N-channel MOSFET output stage with 0.9V typical saturation voltage and 2.2A peak current limit, enabling stable buck conversion without external frequency-setting components.

Feedback is internally trimmed to 5.0V for fixed-output variants-no external resistors required-and regulation is maintained over −40°C to +125°C junction temperature. The device uses voltage-mode control with built-in compensation, requiring only four external components: input capacitor, output capacitor, catch diode, and inductor.

Key Specifications

Pinout & Package

LM2575T-5.0/LB03 is housed in a 5-lead TO-220 package (Package Number NDH0005D) with an electrically connected metal tab (Pin 5) for thermal dissipation and mechanical mounting. Pin 1 is Input, Pin 2 is Output, Pin 3 is Ground, Pin 4 is Feedback (internally tied to 5.0V reference), and Pin 5 is Tab/Case (connected to Pin 3).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM2575T-5.0/KC0005A, LM2575T-5.0/LB03 offers identical performance with distinct manufacturing traceability; compared with LM2575HVT-5.0/LB03, it trades 20V input headroom for lower unit cost and qualification scope in standard 12V/24V applications.

Availability

LM2575T-5.0/LB03 is available at Aetrix Electronics and suitable for industrial power supplies, embedded controller rails, and point-of-load converters requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for LM2575T-5.0/LB03 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 architecture and reliability validation.

The LM2575 series was designed specifically for cost-sensitive, medium-power DC-DC conversion in industrial, automotive, and consumer applications where simplicity, thermal robustness, and minimal external component count are critical.

FAQ

What is the maximum input voltage rating for LM2575T-5.0/LB03?

The LM2575T-5.0/LB03 has an absolute maximum input voltage of 45V and a recommended operating input range of 8V to 40V. Exceeding 40V continuously risks violating the specified output voltage accuracy and thermal limits; for 48V systems, TI recommends the LM2575HVT-5.0/LB03 variant instead. The LM2575T-5.0/LB03 datasheet confirms this rating in the Absolute Maximum Ratings table.

Does LM2575T-5.0/LB03 require external feedback resistors?

No, the LM2575T-5.0/LB03 is a fixed-output variant with internal feedback divider trimmed to 5.0V - Pin 4 (Feedback) is internally connected and requires no external resistors. This distinguishes it from the adjustable LM2575-ADJ version. All electrical characteristics for LM2575T-5.0/LB03 assume this configuration, and adding external resistors would disrupt regulation.

What is the thermal resistance (θ_JA) of LM2575T-5.0/LB03 in its TO-220 package?

The LM2575T-5.0/LB03 in the 5-lead TO-220 package (NDH0005D) has a junction-to-ambient thermal resistance of 65°C/W with minimal PCB copper and 45°C/W with ~4 in² of copper area surrounding the leads. These values are measured per JEDEC standards and appear in the Electrical Characteristics table under "Thermal Resistance." Proper heatsinking is essential to sustain 1A output at elevated ambient temperatures.

Can LM2575T-5.0/LB03 be used in synchronous rectification designs?

No, the LM2575T-5.0/LB03 uses an internal N-channel MOSFET paired with an external Schottky catch diode (e.g., SR103 or MBR340); it does not support synchronous rectification. The datasheet specifies diode-based topology only, and no gate drive signals or timing controls for a second switch are provided. For synchronous operation, TI recommends the TPS5430 or newer LM2678 series.

Is LM2575T-5.0/LB03 RoHS compliant and lead-free?

Yes, LM2575T-5.0/LB03 is manufactured in TI's RoHS-compliant, lead-free TO-220 package per JEDEC J-STD-020 moisture sensitivity level (MSL) 3 requirements. The "LB03" flow code denotes a lead-free assembly process, and TI's official product folder confirms Pb-free status and compliance with EU RoHS Directive 2011/65/EU. Full material declarations are available via TI's Quality & Environmental page.