STMicroelectronics LF80ABDT

Overview

LF80ABDT from STMicroelectronics is a very low dropout (LDO) linear voltage regulator delivering 500 mA output current with 0.45 V typical dropout at 200 mA, ±1% output voltage accuracy (8.0 V), and logic-controlled shutdown (TTL-compatible enable pin). It operates from -40°C to +125°C and requires only a 2.2 µF ceramic output capacitor for stability - ideal for space-constrained, battery-powered industrial sensors and portable instrumentation.

For engineers reviewing the LF80ABDT datasheet, LF80ABDT pinout, LF80ABDT application, or LF80ABDT equivalent, key selection considerations include its 8.0 V fixed output, 0.45 V dropout at 200 mA, 50 µA quiescent current in OFF mode, and PENTAWATT-5 package with integrated thermal/current protection - critical for low-power always-on subsystems and automotive body electronics.

Technical Context

The LF80ABDT implements a PNP pass transistor architecture enabling ultra-low dropout voltage and high PSRR (80 dB typ. at 120 Hz). Its internal bandgap reference and error amplifier maintain tight output regulation across load (5–500 mA), line (VI = 9–16 V), and temperature (-40 to 125°C) variations.

Shutdown is controlled via Pin 2 (INH), which accepts TTL-level logic: ≤0.8 V disables the regulator (50 µA IQ), ≥2.0 V enables it (500 µA IQ). The device includes internal current limiting and thermal shutdown, with R_thJC = 3°C/W and R_thJA = 50°C/W in PENTAWATT-5 package.

Key Specifications

Pinout & Package

PENTAWATT-5 (vertical mount, 5-pin) package with exposed tab for thermal dissipation. Pin 1 = Input, Pin 2 = Inhibit (TTL-compatible enable), Pin 3 = Ground, Pin 4 = Output, Pin 5 = Bypass (not used in standard configuration; tied to GND or left open per design).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LDO regulator applications.

Compared with LDL112PU33R and TLV70780PDQNR, LF80ABDT uniquely combines 8 V output, 500 mA capability, integrated thermal/current protection, and 50 µA shutdown current in a rugged PENTAWATT package - making it the only choice for high-reliability 8 V LDO applications requiring robustness and extended battery life.

Availability

LF80ABDT is available at Aetrix Electronics and suitable for automotive body electronics, industrial sensor nodes, portable medical instruments, and smart meter analog front-ends requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LF80ABDT 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

STMicroelectronics is a global semiconductor leader designing and manufacturing power management, analog, microcontroller, and automotive-grade ICs with emphasis on reliability and industrial qualification.

The LF00 series was developed specifically for low-noise, low-power applications in battery-operated and automotive systems - prioritizing ultra-low dropout, minimal quiescent current, and robust thermal behavior in TO-style packages.

FAQ

What is the minimum input voltage required for regulation at full 500 mA load?

At 500 mA, the maximum dropout voltage is 0.7 V (per LFxxAB specs). With an 8.0 V nominal output, the minimum input voltage is 8.7 V. This ensures regulation remains active even as input sags - critical for 9 V battery or unregulated 12 V rail applications.

Can LF80ABDT be used without the INH (Pin 2) connection?

Yes - tying Pin 2 to VI (input) or leaving it open (with appropriate pull-up per layout) forces the device into permanent ON mode. However, doing so forfeits the 50 µA shutdown current benefit and removes system-level power gating capability.

Is an input capacitor mandatory, and what value is recommended?

A 0.1 µF X7R ceramic capacitor placed within 5 mm of Pin 1 (VI) and Pin 3 (GND) is mandatory for stability and transient response. Larger values (e.g., 1–10 µF) may improve ripple rejection but are not required for basic functionality.

Does LF80ABDT require a specific ESR range for the 2.2 µF output capacitor?

Yes - the datasheet specifies ESR between 0.1 Ω and 10 Ω for the 2.2 µF output capacitor. X7R ceramics typically fall within 0.01–0.1 Ω ESR; adding a small series resistor (e.g., 1 Ω) may be necessary to meet the lower bound if instability occurs.