32.768 kHz CMOS oscillator — the RTC clock spine
The ASEK-32.768KHZ-L-R-S-T: 32.768 kHz is the industry-standard RTC reference — the divider ratio to one second is a clean power of two (2^15), which is why every real-time clock crystal uses this frequency; ±25ppm stability translates to a worst-case time drift of roughly ±2.16 seconds per day, or about ±1.3 minutes per month at temperature extremes.
3.2 × 2.5 mm SMD footprint and 3.3 V power budget
Maximum supply current is 3.5 mA at 3.3 V — modest enough that a coin-cell backup can hold the rail during main-power loss, but verify the host RTC input filter does not rely on the oscillator being continuously active when it is gated off.
Sourced to order against BOM quantities through independent distribution, with availability and current lead times confirmed at RFQ.