Texas Instruments LM1117T-2.85/NOPB

Overview

LM1117T-2.85/NOPB from Texas Instruments is a fixed-output, low-dropout linear voltage regulator delivering 2.85 V at up to 800 mA with 1.2 V dropout at full load, ±1% output voltage accuracy over 0°C to 125°C, and integrated thermal shutdown and current limiting. It serves as a post-regulator for DC–DC converters in embedded power rails requiring stable, low-noise 2.85 V supply.

For engineers reviewing the LM1117T-2.85/NOPB datasheet, LM1117T-2.85/NOPB pinout, LM1117T-2.85/NOPB application, or LM1117T-2.85/NOPB equivalent, key selection criteria include dropout voltage at 800 mA, thermal resistance in TO-220 package, minimum 10-µF tantalum output capacitance requirement, and compatibility with fixed-voltage system rails where precision 2.85 V is specified.

Technical Context

The LM1117T-2.85/NOPB uses an internal bandgap reference trimmed to ±1% accuracy and a PNP pass transistor architecture enabling low dropout operation. Its feedback loop is fully internal-no external resistors required-making it functionally distinct from the adjustable LM1117-ADJ variant.

It operates across 0°C to 125°C junction temperature range with guaranteed line regulation ≤0.2% and load regulation ≤0.4%, and requires a minimum 10-µF tantalum output capacitor for stability and transient response. Thermal shutdown activates at ~150°C junction temperature, and current limit is internally set at 800–1500 mA.

Key Specifications

Pinout & Package

LM1117T-2.85/NOPB uses the TO-220 (3-pin) package: 14.986 mm × 10.16 mm body, vertical mounting, metal tab electrically connected to VOUT for heatsinking. Pin 1 = GND, Pin 2 = VOUT (tab), Pin 3 = VIN.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-dropout linear regulator applications.

Compared with LM1117T-2.85/NOPB, the LM1117T-2.85 offers identical performance with relaxed process certification, while the LD1117S285TR trades precision and thermal capability for compactness-making LM1117T-2.85/NOPB optimal for industrial applications demanding both accuracy and robust thermal management.

Availability

LM1117T-2.85/NOPB is available at Aetrix Electronics and suitable for industrial control systems, portable instrumentation, and battery-powered medical devices requiring stable component supply with long-term lifecycle assurance.

Supply support for LM1117T-2.85/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 ICs, with decades of expertise in precision linear regulators and industrial-grade power solutions.

The LM1117 product line was designed for cost-sensitive, high-reliability linear regulation in industrial, computing, and communications infrastructure-emphasizing dropout performance, thermal robustness, and ease of use in fixed-voltage applications.

FAQ

What is the minimum input voltage required for LM1117T-2.85/NOPB to maintain regulation?

The LM1117T-2.85/NOPB requires a minimum input voltage of 4.05 V to sustain regulation at full 800 mA load, based on its 1.2 V dropout specification. At lighter loads, dropout decreases-for example, 1.1 V at 100 mA-allowing operation down to ~3.95 V. Input must remain below 15 V maximum rating.

Does LM1117T-2.85/NOPB require external capacitors, and what values are mandatory?

Yes, LM1117T-2.85/NOPB requires a minimum 10-µF tantalum capacitor on the output for stability and transient response. An input capacitor (≥10 µF tantalum) is strongly recommended. Ceramic capacitors may be used if ESR is ≥0.3 Ω; otherwise, add series resistance to meet ESR requirements.

Is LM1117T-2.85/NOPB pin-compatible with other LM1117 fixed-voltage variants?

Yes, all LM1117 fixed-voltage TO-220 variants-including LM1117T-2.85/NOPB, LM1117T-3.3/NOPB, and LM1117T-5.0/NOPB-share identical pinout (GND–VOUT–VIN), package dimensions, and thermal pad connection. This allows direct substitution in layouts where output voltage change is acceptable.

What thermal considerations apply when using LM1117T-2.85/NOPB in a sealed enclosure?

In sealed enclosures, LM1117T-2.85/NOPB's TO-220 package has θ_JA = 23.8°C/W. With 1 W dissipation (e.g., 5 V_IN → 2.85 V_OUT, 470 mA), junction rise is ~23.8°C above ambient. At 60°C ambient, T_J reaches 83.8°C-well within 125°C limit. For >2 W dissipation, forced air or external heatsink is advised.

How does LM1117T-2.85/NOPB handle short-circuit conditions?

LM1117T-2.85/NOPB incorporates foldback current limiting and thermal shutdown. Under short-circuit, output current is limited to 800–1500 mA depending on junction temperature; if sustained, thermal shutdown activates at ~150°C and cycles until fault clears. No external protection diode is needed for standard operation.