STMicroelectronics STLQ015XG28R

Overview

STLQ015XG28R from STMicroelectronics is a 150 mA ultra-low-quiescent-current linear voltage regulator in SOT23-5L package, delivering 2.8 V output with ±2% tolerance at 25 °C, 112 mV typical dropout at 150 mA, and 1.4 µA quiescent current under full load - designed for battery-powered microcontroller power rails requiring multi-year standby life.

For engineers reviewing the STLQ015XG28R datasheet, STLQ015XG28R pinout, STLQ015XG28R application, or STLQ015XG28R equivalent, key selection criteria include shutdown current (≤200 nA at 125 °C), ceramic capacitor compatibility (1 µF min), logic-controlled enable, thermal/short-circuit protection, and operation across –40 °C to 125 °C.

Technical Context

The STLQ015XG28R integrates a P-channel pass transistor with internal current limiting and thermal shutdown at 170 °C (15 °C hysteresis). Its enable input accepts logic-level control (VEN low ≤0.4 V, high ≥0.7×VIN) and drives <200 nA input current.

It achieves stable regulation with 0.47–10 µF ceramic output capacitors (ESR 0.056–6 Ω), delivers 40 dB PSRR at 1 kHz, and maintains 75 µVRMS output noise (10–100 kHz) at 0.8 V output - confirming suitability for low-noise sensor and RF subsystem biasing.

Key Specifications

Pinout & Package

SOT23-5L package: 5-pin surface-mount, 2.95 mm × 1.60 mm footprint, 1.45 mm height, ECOPACK® compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6209B28MR-G and RP111N281D-TR-F, the STLQ015XG28R uniquely combines 1 nA shutdown current, integrated thermal shutdown, and 125 °C-rated operation - making it optimal for sealed, long-life, thermally constrained battery systems.

Availability

STLQ015XG28R is available at Aetrix Electronics and suitable for wearable health monitors, smart meter sensor nodes, industrial wireless sensors, and automotive cabin controllers requiring stable component supply over extended product lifecycles.

Supply support for STLQ015XG28R 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 products for automotive, industrial, and consumer markets.

The STLQ015 series belongs to ST's ultra-low-power linear regulator portfolio, engineered specifically for energy-harvesting and battery-operated systems demanding nanoscale shutdown current and extended temperature resilience.

FAQ

What is the minimum input voltage required to maintain 2.8 V output at 150 mA load?

The STLQ015XG28R requires a minimum input voltage of 2.912 V (2.8 V + 112 mV dropout) to sustain regulation at full load. At elevated temperatures up to 125 °C, dropout increases to 300 mV, raising the minimum input to 3.1 V. Operation below these thresholds causes output collapse into dropout.

Can the STLQ015XG28R be used with a 0.47 µF ceramic output capacitor?

Yes - the datasheet explicitly guarantees stability with 0.47 µF ceramic capacitors (X5R/X7R) having ESR between 0.056 Ω and 6 Ω. This enables compact designs where space constraints preclude 1 µF caps, though 1 µF is recommended for best PSRR and transient response.

Does the NC pin (Pin 4) require any PCB layout treatment?

Pin 4 is internally unconnected and must remain electrically floating. ST recommends leaving it unconnected on the PCB; grounding or routing traces to it may introduce parasitic coupling or violate SOT23-5L mechanical specifications. No thermal or electrical function is assigned to this terminal.

How does the enable pin behave during power-up when VIN rises before EN is asserted?

The STLQ015XG28R remains in shutdown until EN exceeds 0.7×VIN. During VIN ramp-up, EN must be held low (≤0.4 V) or left open (with <200 nA leakage) until VIN stabilizes; premature EN assertion before VIN reaches regulation threshold may cause erratic turn-on or delayed output rise due to insufficient gate drive margin.