STMicroelectronics LK115D30

Overview

LK115D30 from STMicroelectronics is a very low-dropout linear voltage regulator delivering 3.0 V at up to 100 mA output current, with 0.17 V typical dropout at 60 mA, ±3% output tolerance at 25 °C, and dual logic-controlled shutdown (pins 2 and 3). It targets battery-powered systems requiring ultra-low quiescent current (0.01 µA in off mode) and high PSRR (79 dB at 120 Hz).

For engineers reviewing the LK115D30 datasheet, LK115D30 pinout, LK115D30 application, or LK115D30 equivalent, key selection factors include its SO-8 package, dual active-HIGH/active-LOW enable control, 2.2 µF minimum output capacitance requirement, and operation across –40 °C to 125 °C junction temperature.

Technical Context

The LK115D30 integrates internal current and thermal limiting, operates with input voltages up to 20 V, and maintains regulation down to VI = VO + 0.17 V. Its dual enable architecture supports flexible power sequencing: pin 2 (ON/OFF) requires ≥2.4 V for ON when pin 3 is grounded, while pin 3 (ON/OFF) requires ≤(VIN − 2.4 V) for ON when pin 2 is tied to VIN.

It achieves 66 µV RMS output noise (10 Hz–100 kHz), 79 dB supply voltage rejection at 120 Hz, and stable operation with only 2.2 µF ceramic output capacitor (ESR 0.5–10 Ω), eliminating need for large electrolytics in space-constrained designs.

Key Specifications

Pinout & Package

Supplied in an SO-8 package (ECOPACK®, lead-free, JEDEC-standard footprint), the LK115D30 uses a standard 8-pin small-outline integrated circuit body with 1.27 mm pitch and 5.0 mm × 4.0 mm outline.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-dropout, dual-enable voltage regulator applications.

Compared with XC6219B302MR-G and AP7361-30SG-7, the LK115D30 uniquely provides dual independent enable inputs in SO-8, lowest shutdown IQ (0.01 µA), and lowest dropout (0.17 V), making it optimal for ultra-low-power, multi-domain power management where precise sequencing and minimal leakage are mandatory.

Availability

LK115D30 is available at Aetrix Electronics and suitable for wearable health monitors, automotive body control modules, industrial sensor nodes, and medical point-of-care devices requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LK115D30 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 headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, power management ICs, sensors, and analog chips for industrial, automotive, and consumer markets.

The LK115XX series belongs to ST's precision low-dropout regulator product line, engineered specifically for ultra-low-power, battery-operated applications demanding dual enable control, wide temperature operation, and minimal external components.

FAQ

What is the minimum input voltage required for regulation at full 100 mA load?

The LK115D30 maintains regulation as long as input voltage remains ≥ VO + VDROP. With 0.17 V typical dropout at 60 mA and 0.2 V maximum at 100 mA (per datasheet trend), minimum input is 3.0 V + 0.2 V = 3.2 V. At light loads (<10 mA), dropout drops to ~0.1 V, allowing operation down to 3.1 V.

Can both enable pins be used simultaneously, and what happens if conflicting logic is applied?

No - the truth table explicitly prohibits "L H" (pin 2 low, pin 3 high), defining it as NOT ALLOWED. Applying this state may cause undefined output behavior or increased quiescent current. Valid combinations are H L (ON), H H (OFF), and L L (OFF); pin 2 and pin 3 must never be driven to opposite active states.

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

Yes - a minimum 0.1 µF ceramic capacitor is required between IN and GND, placed as close as possible to pins 1 and 4. This stabilizes the input impedance, prevents oscillation during transient load steps, and improves PSRR. Larger values (e.g., 1 µF) are acceptable but not necessary for basic stability.

Does the LK115D30 support reverse-voltage or reverse-current protection?

No - the device lacks built-in reverse-voltage or reverse-current protection. If input polarity reversal or back-driving from the output is possible in the system, external protection (e.g., series Schottky diode on IN or MOSFET-based ideal diode) must be added to prevent damage or latch-up.