STMicroelectronics STLQ020C18R

Overview

STLQ020C18R from STMicroelectronics is a 200 mA ultra-low-quiescent-current low-dropout (LDO) voltage regulator in SOT323-5L package, delivering fixed 1.8 V output with ±2% accuracy at 25 °C and ±3% over −40 °C to +125 °C. It operates from 2 V to 5.5 V input, achieves 160 mV dropout at 200 mA, and draws only 300 nA quiescent current at no load-enabling multi-year battery life in always-on wearable and medical sensors.

For engineers reviewing the STLQ020C18R datasheet, STLQ020C18R pinout, STLQ020C18R application, or STLQ020C18R equivalent, key selection criteria include its sub-1 µA shutdown current (5 nA typ.), logic-controlled EN pin with no internal pull-up, output discharge capability (optional), and thermal/overcurrent protection-critical for space-constrained, battery-powered edge nodes requiring long-term reliability without external supervision.

Technical Context

The STLQ020C18R employs an adaptive biasing circuit that maintains ultra-low I_q while enabling fast transient response and 52 dB PSRR at 100 Hz (V_OUT = 2.5 V, 10 mA load). Its bandgap reference and opamp-based control loop ensure stable regulation across temperature and load, with line regulation as tight as 0.005 %/V and load regulation of 0.0015 %/mA at 25 °C.

Thermal protection activates at 160 °C (20 °C hysteresis) only when load exceeds 1 mA; below that threshold, thermal shutdown is disabled to preserve sub-µA operation. The device integrates constant-current limiting (380 mA typ.) and requires no external compensation-stabilized with ≥1 µF ceramic capacitors on both input and output.

Key Specifications

Pinout & Package

SOT323-5L package: 5-pin surface-mount, 2.0 × 1.8 mm footprint, exposed pad connected to GND for thermal enhancement. Compatible with standard reflow profiles and high-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6210B182MR-G and RP114K181D-TR, STLQ020C18R uniquely combines sub-µA shutdown (5 nA), integrated output discharge, and thermal hysteresis-making it optimal for safety-critical, maintenance-free medical and industrial edge nodes where leakage and fault recovery behavior are design-determining.

Availability

STLQ020C18R is available at Aetrix Electronics and suitable for smartphone image sensor biasing, wearable physiological monitoring, and portable medical diagnostics requiring stable component supply with guaranteed long-term manufacturability and traceable sourcing.

Supply support for STLQ020C18R 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 STLQ020 series belongs to ST's ultra-low-power LDO portfolio, engineered specifically for battery-operated edge devices demanding nanowatt-level quiescent consumption without sacrificing transient performance or protection robustness.

FAQ

What is the minimum input voltage required for stable 1.8 V output at 200 mA?

The STLQ020C18R requires VIN ≥ VOUT + VDROP = 1.8 V + 0.16 V = 1.96 V for full-load regulation. Per datasheet Table 4, dropout is specified at 160 mV for VOUT = 2.5 V; for 1.8 V output, typical dropout is 150–165 mV across temperature. Operation below 1.96 V enters dropout, where output declines linearly but Iq remains controlled.

Can the EN pin be left unconnected if shutdown functionality is not needed?

No-the EN pin has no internal pull-up and must not be left floating. To maintain permanent ON state, tie EN directly to VIN. Leaving it unconnected risks undefined logic state, intermittent shutdown, or increased susceptibility to ESD-induced toggling due to high-impedance node.

Does STLQ020C18R support output discharge, and how is it enabled?

Yes-output discharge is implemented on specific versions (marked "R" suffix variants like STLQ020C18R) and activated automatically when EN is pulled low. Internal 100 Ω discharge path (RLOW) discharges VOUT to GND within milliseconds, preventing back-powering of upstream circuits or latch-up in multi-rail systems.

How does thermal protection behave under light-load conditions?

Thermal shutdown is disabled when load current falls below 1 mA-ensuring Iq stays ≤1 µA even at elevated ambient temperatures. Protection engages only above 1 mA, triggering at 160 °C with 20 °C hysteresis. This design preserves ultra-low-power operation in standby while safeguarding against overload faults during active use.