Nano-quiescent synchronous buck for battery-powered designs
The ST1PS01FJR is a 400 mA nano-quiescent synchronous step-down buck converter from STMicroelectronics, part of the ST1PS01 family. It targets always-on, battery-operated systems where the quiescent current floor directly sets the standby battery life. The 2 MHz fixed switching frequency keeps the inductor and output capacitor small enough for space-constrained wireless sensor nodes and wearable PCBs. Output is fixed at one of four factory-set voltages: 1.05 V, 1.25 V, 1.35 V, or 1.55 V. The synchronous rectifier eliminates the external Schottky diode, saving board area and raising efficiency at light loads.
Package, temperature grade, and PCB integration
Housed in an 8-UFBGA, FCBGA (FlipChip) package with a supplier device package size of 1.11x1.41 mm. The 0.4 mm ball pitch demands a controlled solder-paste stencil and a micro-via-capable PCB stack-up for fan-out.
For a second-source hedge within the same family, the ST1PS01HJR shares the same 400 mA output, 2 MHz switching, and 8-FlipChip package, but with a different fixed output voltage set. Confirm the BOM's target voltage before substituting.