The DSC1033BI1-004.0000 is a MEMS-based XO (Standard) from Microchip's PureSilicon™ series, delivering a 4 MHz CMOS clock output from a 3.3V rail.
Standby pin for low-power sleep modes
The 3mA typical active draw at 4 MHz is low enough that the standby savings only matter when the sleep-to-active duty cycle is heavily weighted toward sleep.
Microchip lists the DSC1033BI1-004.0000 as Obsolete. For a new design, consider the active DSC1033 family siblings in the same 4-SMD no-lead package. The 'CI1' suffix variant (DSC1033CI1-004.0000) shares the same 4 MHz frequency, 3.3V supply, and CMOS output but may carry a different stability grade or temperature range — verify the datasheet before substituting.