I have numerous switchers that have been sampled to me over the years, yet I've never, Never, NEVER put one into an application. They're noisier than linears, at best, at least twice as much so as the cheapest and simplest linear supply, and still cost WAY more than a linear supply. When I run into a temperature or weight sensitive application, I'll think about 'em, but, for now, I like the <<50 mV noise level of the $2 linears. When properly applied, filtered, and bypassed, Vcc under full load with all the noise should still remain within ~80 mV of its DC rating at frequencies from DC to 100 MHz.

I've "played" with several reset/supervisor IC's. What I had in mind was carefully studying the behavior of the OSC-out pin on the MCU with respect to the Vcc level. I suspect that the reason my linear-powered 805x's don't work with switchers is that the startup transient is doing something to the MCU.

I'm thinking that if I allow the osc-out pin to drive a 2-bit shift-register with an XOR across it, it will produce a 2-cycle long reset pulse, as specified in one or another datasheet.

There ought to be a specificaiton for the RC circuit that all mfg's show in combination with 805x's, that actually works. I'm thinking it's no accident that the popularity of these reset IC's has developed over the same period during which small, low-cost switchers have become common, though.

RE