I'd like to implement a clock distribution system with a clock source (24MHz) switchover in the case of failure. Not exactly a trivial problem, especially when a smooth transition between the clocks is required. Best to be delagated to a ready-made chip, which... barely exists. The only two chips I was able to find are the ICS581-2 (perfect match for my needs) and ICS580 (3 cycle stall, don't know yet if it's a problem or not). The first one turns out to be unobtainium and Mouser labels it as obsolete. So what is the modern way of doing this? I don't think I have a sudden attack of dysgooglia, there seems not to be much about the issue.
On a similar note: what oscillators should be used? Two exact copies of the same part, or a combo of a crystal oscillator and a MEMS? Is there any wisdom handed down over the ages about the long-term reliability of MEMS oscillators?
Best regards, Piotr