The DSC1121DL5-026.0000T: This is a MEMS-based oscillator, not a quartz crystal. The MEMS resonator is less prone to shock-induced frequency jumps and has a tighter initial accuracy than a bulk quartz blank. If you are replacing a quartz oscillator on a board that sees vibration or thermal cycling, the MEMS die is the part that actually survives longer.
Supply range and output — fit check
Runs from 2.25 V to 3.6 V — covers 2.5 V and 3.3 V rails without a separate regulator. The CMOS output drives standard logic inputs directly; no level translation needed on a 3.3 V bus.
Rated -40 to +105 °C — this is the industrial-plus band. It stays within spec in an outdoor telecom enclosure or a factory floor controller that sees elevated ambient temperatures.
The base product number is DSC1121; the full suffix specifies the stability grade and frequency.