[time-nuts] Microchip PIC CTMU

[David]

I ran a search through the time-nuts archives and found only one
mention of this a couple years ago asking the same question which is,
has anybody explored the capabilities of the Microchip PIC CTMU for
use as a time to digital converter or programmable delay?

The Microchip datasheets lack detailed performance specifications but
my conservative estimate is that resolution down to 500ps over 200ns
using the built in 10 bit ADC should be possible without complex
calibration.  (The PIC series ADCs with more than 10 bits are pretty
horrible.)

See What You Can Do with the CTMU:
http://ww1.microchip.com/downloads/en/AppNotes/CTMU%2001375a.pdf

Overview of Charge Time Measurement Unit (CTMU):
http://www.microchip.com/stellent/groups/SiteComm_sg/documents/DeviceDoc/en542792.pdf

PIC18(L)F2X/4XK22 w/10 Bit ADC:
http://ww1.microchip.com/downloads/en/DeviceDoc/39977f.pdf

PIC18F66K80 w/12 Bit ADC:
http://ww1.microchip.com/downloads/en/DeviceDoc/39977f.pdf

I prefer more discrete implementations but this might be useful for
its higher integration, lower cost, and simplicity in less demanding
applications.