A low quiescent current LDO is a low-dropout voltage regulator optimized to operate with a drastically low quiescent current (Iq, or self-consumption), which is lower than or comparable to the average load current it supplies.

This feature is necessary for power-budgeted applications, such as battery-powered devices or green-compliant equipment  with long stand-by operation, where it helps extend the battery life and reduces the overall power consumption.

ST’s series of low quiescent current LDO regulators is ideal for portable consumer devices, such as smartphones, smart watches, Bluetooth earphones, and wearables. Industrial, smart building and smart-home sensors can also benefit from the very low quiescent current, both in operating and disabled (stand-by) modes. Other applications include smart meters, healthcare devices and coin-cell powered devices.

Various small footprint package options are available including the SOT23-5L, SOT323-5L, Flip-Chip4 from 0.65 x 0.65 mm and DFN from 1 x 1 mm.

STLQ020 Ultra-low consumption

STLQ020 series of 200 mA low-dropout voltage regulators has a quiescent current as low as 300 nA, without any compromise on performance. Thanks to a dedicated low power design and load-adaptive circuity, the STLQ020 offers much better dynamic behavior than other comparable LDOs on the market, such as higher PSRR (> 40 dB up to 200 kHz) and faster line/load transient response. It is the ideal companion to supply low-consumption microcontrollers, sensors and other small loads in space-constrained devices powered by coin or Li-Ion cells and working mainly in stand-by mode. The STLQ020’s tiny flip-chip-4 and DFN-6 packages can fit wellness monitors, medical sensors, and wireless IoT devices. The STLQ020 operates with an input voltage from 1.5 to 5.5 V, with a selection of output voltages from 0.8 to 4.5 V plus an adjustable version.

STLQ015 ultra-low quiescent current linear regulators

The  STLQ015 ultra-low consumption LDOs provide up to 150 mA current from an input voltage ranging from 1.5 to 5.5 V. They feature a quiescent current of just 1.4 μA at the maximum load and a standby current of typically 1 nA, extending the battery lifetime in those applications requiring very long standby time. Requiring only two small external capacitors, they provide a cost-effective and space-saving solution for powering microcontrollers in portable and battery-powered systems, electronic sensors, home medical instruments and portable entertainment gadgets. The STLQ015 series is available in a wide range of output voltages, from 0.8 V to 3.3 V in 100 mV steps. 

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