I am designing a system that really needs a switched capacitor filter or ten. For now I have stuck in the Linear ones that are singles in an SO-8. I have been looking for another maker to see if I have other options and have found to my alarm that it appears that Linear is the only source I can trust.
National: The parts can still be found on the web site with google but there seems to be no way to get to them from the main page. This is usually a sign that the company is about to drop the product line.
Maxim: I've been burned too many times by these guys. They make lots more datasheets than actual parts.
TI: These appear to be only second source versions of the National parts.
Does anyone know of another company that I may have missed? I need to kill off something at, lets say 7KHz on a signal at 1KHz and I have clocks from 1KHz to 128KHz. The actual numbers vary over a 5:1 range so a fixed tuning would have to be a way better filter than one I can tune by changing the clock.