In last week's meeting, I noted I had been looking at the schematics for
Fox-1 and RT-IHU and found the circuits for the latchup protection and
watchdog functions. I admit this might be basic to some, but I'm finding
it fascinating! Anyway...
Since last week's meeting, I researched the parts used:
onsemi FPF2001 is a current limit switch used on both Fox-1 and half the
RT-IHU. It's obsolete, replaced by onsemi's FPF2000. But the FPF2000 is
listed as end-of-life. It's replacement part is the TI TPS22942.
MAX4995 is a current limit switch used on the other half of the. This
part looks good for new designs.
For the watchdog functionality, both Fox-1 and RT-IHU use the
STWD100NYWY3F chip. this parts looks good for new designs.
That's as far as I got. Next, I want to research the Fox-1 and RT-IHU
designs to determine the thresholds of the current limit switches. In
particular, I want to see if the TPS22942 is a suitable replacement,
assuming we have the same current requirements.
That's where I'm at,
Radio Amateur Satellite Corporation