SiTime is a specialist in MEMS timing products that challenge typical quartz crystals. One of their offerings is the SiT1552 series of MEMS oscillators. We’ve had questions recently concerning the ‘E’ suffix on some of these products, and whether it affects the device’s specifications.
The ‘E’ suffix on this product does affect its specifications. Per the product’s datasheet (download link), the ‘E’ suffix indicates the device’s temperature stability. ‘E’ is the tightest at 5ppm, while ‘F’ indicates 10ppm temp stability and 1 indicates 20ppm temp stability. Tighter stability values can easily drop in for looser ones, i.e. E will work when you need F or 1, but the opposite is not necessarily true and should be checked with your engineering people prior to purchase.