ON Semiconductor’s NCP171 is a dual-mode Low Drop-Out (LDO) regulator which helps designers prolong the battery run-time of IoT devices by limiting the current drawn to almost nothing when the system is inactive.
The NCP171, a Super Low Iq (SLIQ) LDO, has an innovative dual-mode architecture which features two different LDO cores, one for use in Active mode, the other for Low-power mode. A signal on the device’s Eco pin triggers switching between modes.
This dual-mode architecture mirrors the dual-mode operation of a typical battery-powered IoT node: in Active mode, it periodically performs intensive operations such as RF transmission, returning to Low-power mode when the system is either sleeping or executing tasks that draw very little battery power.
In these IoT nodes, energy usage in Low-power mode makes up by far the larger proportion of total power consumption. This means that the LDO’s quiescent current, Iq, is a vitally important parameter, as is its ability to provide high performance in Active mode.
In Low-power mode, the NCP171 draws only 50nA at no load. This mode also offers a built-in voltage offset factory-programmable to 50mV, 100mV, 150mV or 200mV, to further reduce system power consumption.
In Active mode, the NCP171 can provide up to 80mA of output current with excellent transient response for demanding RF and sensor applications, while maintaining a high power-supply rejection ratio of up to 65dB, and a typical drop-out voltage of just 41mV.
The LDO comes in a 1.2mm x 1.2mm package and is stable with only two 1μF capacitors, offering a smaller board footprint with fewer external components, higher system efficiency and lower overall cost than a circuit based on a buck regulator.
The STR-NCP171-EVK kit can be used with the Strata environment GUI which can enable/disable the LDO, switch between Active mode and Low-power mode, and monitor other telemetry on the platform, including input and output voltage, power dissipated and temperature.
NCP171: Highly stable output with excellent transient response