ST1PS02 Datasheet 400 mA nano-quiescent synchronous step-down converter with digital voltage selection, Power Good and AUX switch Features 500 nA input quiescent current at V = 3.6 V (not switching) IN 92% typical efficiency at 10 mA load (V = 3.6 V, V = 2.5 V) IN OUT 100% duty cycle 1.8 V to 5.5 V input operating range Undervoltage lockout: 1.57 V (V falling, typ.) IN Up to 400 mA output current capability Low power control operation for the best efficiency Embedded soft-start circuit Tiny external components: L = 2.2 H typ. Settable inductor current limitation Selectable output voltages: 1.0 V to 3.3 V Output voltage Power Good 1.5% output voltage accuracy (V , T = 25 C) OUT A Dynamic output voltage selection (D0, D1 and D2) Auxiliary load switch Vout2 (AUX control input) Available in TQFN12 package Applications Wearable applications Product status link Personal tracking monitors Smart watches, sport bands ST1PS02 Energy harvesting, wireless sensors Wearable and fitness accessories Industrial sensors, portable low power devices Single cell Li-Ion battery applications Bluetooth low energy Zigbee Description The ST1PS02 is a nano-quiescent miniaturized synchronous step-down converter, which is able to provide up to 400 mA output current with an input voltage ranging from 1.8 V to 5.5 V. This converter is specifically designed for applications where high efficiency, PCB size and thickness are the key factors. The output voltage can be set using three digital control inputs, a V from 1.0 V to 3.3 V can be dynamically OUT selected. Thanks to the enhanced PCC (peak current control) the ST1PS02 reaches very high efficiency conversion using just a 2.2 H inductor and two small capacitors. The device embeds a controlled load switch to supply a subsystem with same voltage rail. Advanced design circuitry is implemented to minimize the quiescent current. The device is available in thin plastic package. DS13206 - Rev 4 - July 2021 www.st.com For further information contact your local STMicroelectronics sales office.ST1PS02 Application schematic 1 Application schematic Figure 1. ST1PS02 application schematic Table 1. Typical external components Component Description Value Size - imperial (metric) C Ceramic capacitor with low ESR values 1 10 F 0603 (1608) C , C Ceramic capacitor with low ESR values 2 3 L1 Inductor 2.2 H 0806 (2016) R Pull-up resistor 1 M 1 0402 (1005) R Current limit resistor 0 2 DS13206 - Rev 4 page 2/26