This application note gives an overview of on-chip 32 kHz oscillator modes used in low power MCUs and the different drive settings supported by the SiT15xx families. The SiT15xx devices feature NanoDrive™, a factory programmable output voltage swing to optimize power and connectivity to existing oscillator sustaining circuits. This document lists valid combinations of SiT15xx output drive VOH/VOL settings and the associated part number for specific MCUs.