Texas Instruments LM1117MP-1.8

Overview

LM1117MP-1.8 from Texas Instruments is a fixed-output, 1.8 V, 800 mA low-dropout linear regulator in SOT-223 package, featuring 1.2 V dropout at 800 mA, ±1% output voltage accuracy over 0°C to 125°C, and integrated thermal shutdown and current limiting. It delivers stable power for microprocessor core supplies and post-regulation of DC–DC converters.

For engineers reviewing the LM1117MP-1.8 datasheet, LM1117MP-1.8 pinout, LM1117MP-1.8 application, or LM1117MP-1.8 equivalent, key selection considerations include dropout voltage at full load, thermal resistance (R_θJA = 61.6°C/W), minimum required 10 µF tantalum output capacitor, and compatibility with 3.2–10 V input range for 1.8 V output regulation.

Technical Context

The LM1117MP-1.8 uses a bandgap reference trimmed via Zener diode to maintain ±1% output voltage accuracy across temperature and load. Its internal PNP pass transistor enables low dropout operation, with quiescent current as low as 5 mA and ripple rejection of 60 dB at 120 Hz.

It operates within 0°C to 125°C junction temperature range and includes foldback current limiting and thermal shutdown. The device requires no external components for basic operation but mandates ≥10 µF tantalum output capacitance for stability and transient response.

Key Specifications

Pinout & Package

SOT-223 (MP) package: 4-pin thermally enhanced plastic surface-mount package with exposed tab (pin 2/TAB connected to VOUT for thermal conduction).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV1117-18CDCYR and MCP1700-1802E/TO, the LM1117MP-1.8 uniquely balances high output current (800 mA), robust thermal performance in SOT-223, and proven industrial reliability-making it optimal for core power delivery where both current and stability are essential.

Availability

LM1117MP-1.8 is available at Aetrix Electronics and suitable for microprocessor core supplies, post-regulation of DC–DC converters, and battery-powered instrumentation requiring stable component supply and long-term industrial availability.

Supply support for LM1117MP-1.8 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 designing analog ICs, embedded processors, and power management solutions for industrial, automotive, and communications markets.

The LM1117 product line delivers cost-effective, thermally robust low-dropout regulators optimized for core voltage regulation and noise-sensitive analog subsystems in space-constrained applications.

FAQ

What is the minimum input voltage required for stable operation of the LM1117MP-1.8?

The LM1117MP-1.8 requires a minimum input voltage of 3.2 V to maintain regulation at full 800 mA load, based on its 1.2 V dropout specification. At lighter loads, input can drop lower-for example, 2.5 V at 100 mA-but design margin should preserve ≥3.2 V input under worst-case conditions. Input below 3.2 V risks dropout and output collapse.

Does the LM1117MP-1.8 require an external capacitor on the ADJ pin?

No-the LM1117MP-1.8 is a fixed-output variant; its ADJ pin is internally connected to ground and does not accept external components. Only the adjustable LM1117-ADJ version uses the ADJ pin for resistor-based output programming. For LM1117MP-1.8, the ADJ/GND pin must be connected directly to system ground.

Can the LM1117MP-1.8 be used without a heatsink in a 25°C ambient environment?

Yes, the LM1117MP-1.8 can operate without an external heatsink at 25°C ambient if power dissipation remains ≤1.6 W-calculated as (V_IN − 1.8 V) × I_OUT. For example, at V_IN = 5 V and I_OUT = 500 mA, dissipation is 1.6 W, matching the limit set by R_θJA = 61.6°C/W. Higher loads or input voltages require PCB copper pour or heatsinking.

What output capacitor is required for stability with the LM1117MP-1.8?

The LM1117MP-1.8 requires a minimum 10 µF tantalum capacitor at the output for guaranteed stability and transient response. Aluminum electrolytic or ceramic capacitors may be used only if their ESR falls within 0.3–22 Ω; standard 10 µF X7R ceramics typically lack sufficient ESR and require series resistance or parallel damping.

Is the LM1117MP-1.8 compatible with lead-free reflow soldering processes?

Yes, the LM1117MP-1.8 in SOT-223 package is rated for lead-free reflow with a peak temperature of 260°C for 4 seconds, per JEDEC J-STD-020. Its package construction and die attach materials meet RoHS and lead-free assembly requirements without derating.