STMicroelectronics STLQ015M18R

Overview

STLQ015M18R from STMicroelectronics is an ultra-low-quiescent-current linear voltage regulator delivering 150 mA output at fixed 1.8 V with input range 1.5–5.5 V, typical dropout of 112 mV, ±2% output voltage tolerance at 25 °C, and logic-controlled shutdown. It serves as a primary power supply for microcontrollers and sensors in battery-constrained portable systems.

For engineers reviewing the STLQ015M18R datasheet, STLQ015M18R pinout, STLQ015M18R application, or STLQ015M18R equivalent, key selection criteria include quiescent current (1.4 µA at 150 mA load), OFF-mode current (1 nA typ.), ceramic capacitor compatibility (1 µF), thermal/overcurrent protection, and SOT23-5L footprint constraints.

Technical Context

This LDO employs a P-channel MOSFET pass element enabling low dropout and near-zero gate drive current, directly supporting its sub-µA quiescent operation. Internal bandgap reference, error amplifier, and precision resistor divider ensure stable 1.8 V output across –40 °C to 125 °C.

The enable input (EN) controls NMOS-driven shutdown, reducing total supply current to 1 nA typ. by disabling bias networks and disconnecting internal references. Thermal shutdown activates at 170 °C with 15 °C hysteresis, and short-circuit current is internally limited to 250–350 mA.

Key Specifications

Pinout & Package

SOT23-5L package: 2.95 mm × 1.60 mm × 1.45 mm body height, 0.95 mm pin pitch, thermally enhanced die pad (exposed copper not connected internally).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultra-low-I_Q LDO applications.

Compared with XC6206P182MR and ADP160ACBZ-1.8-R7, STLQ015M18R uniquely combines nanoscale shutdown current (1 nA), integrated thermal protection, and ceramic-capacitor stability in SOT23-5L-making it optimal for long-life, space-constrained, and thermally variable applications where leakage budget is sub-nA.

Availability

STLQ015M18R is available at Aetrix Electronics and suitable for wearable health monitors, industrial wireless sensor nodes, smart meter RTC backup systems, and portable medical glucose meters requiring stable component supply with guaranteed long-term manufacturability.

Supply support for STLQ015M18R 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 analog, microcontroller, power, and sensor solutions for industrial, automotive, and consumer markets.

The STLQ015 series belongs to ST's ultra-low-power LDO family, engineered specifically for energy-harvesting and battery-operated devices demanding nanoscale shutdown current and extended operational lifetime without compromising protection or stability.

FAQ

What is the minimum input voltage required for regulation at 1.8 V output?

The STLQ015M18R maintains regulation down to 1.5 V input across temperature and load. At 150 mA output, the dropout voltage is 112 mV typ., so VIN must be ≥1.912 V for full specification compliance. The device remains functional (though out-of-regulation) as low as 1.5 V input, per absolute maximum ratings.

Can the STLQ015M18R be used with a 0.47 µF output capacitor?

No-ST specifies a minimum 0.47 µF capacitance but requires ESR between 0.056 Ω and 6 Ω for stability. A 0.47 µF ceramic capacitor typically has ESR <10 mΩ, falling outside the stable region. Use ≥1 µF X5R/X7R MLCC with ESR ≥0.056 Ω, verified via Figure 15 (COUT stability region) in DS6765 Rev 7.

Does the NC pin (Pin 4) require any PCB routing or grounding?

Pin 4 is internally unconnected and must remain floating. ST recommends leaving it un-routed or optionally connecting it to GND solely for mechanical reinforcement-no electrical function is provided. Do not tie to voltage rails or signal lines, as this may compromise thermal performance or cause latch-up.

How does thermal shutdown behave during sustained overload?

When junction temperature reaches 170 °C, the device enters thermal shutdown, turning off the pass transistor and reducing output current to near zero. After cooling by ≥15 °C (hysteresis), it automatically recovers without external intervention. During repeated cycling, average output current is limited by duty cycle and ambient thermal resistance (R_thJA = 255 °C/W).