MEMS clock source for 25 MHz rail
The MEMS resonator is sealed at die level, which eliminates the start-up reliability concerns that quartz crystals pick up from thermal cycling or mechanical shock. Supply voltage spans 2.25V to 3.6V, so the same part works across a 2.5V or 3.3V rail without a separate regulator. The wide tolerance also absorbs supply droop during MCU wake-up transients.
Standby pin and power-down current
That is low enough to keep a battery-backed RTC domain alive while the main processor sleeps, and the CMOS output re-enables in microseconds after the standby pin is released. The MEMS core draws less than a quartz Pierce oscillator of the same output drive, which matters when the clock tree has multiple fan-outs.
Surface-mount only.