I seem to remember that, too. As such, we may need to look at other parts or different versions of the same parts. That depends, obviously on the maximum current draw expected during normal operation. Does anybody on this list know if we have that information for the AX5043 chain?

Jonathan

On 1/19/23 17:40, Rich Gopstein via pacsat-dev wrote:

Burns might remember the details (or Zach certainly would), but one of those parts was undersized for the RT-IHU and would cut out when we were transmitting with the ax5043.  I think we had to back down the xmit power in order for the device not to reset.

Rich

On Thu, Jan 19, 2023 at 5:46 PM Jonathan Brandenburg via pacsat-dev pacsat-dev@amsat.org wrote:

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,

Jonathan


-- 
Jonathan Brandenburg
Radio Amateur Satellite Corporation
1-214-213-1066


-----------------------------------------------------------

pacsat-dev mailing list -- pacsat-dev@amsat.org
View archives of this mailing list at
https://mailman.amsat.org/hyperkitty/list/pacsat-dev@amsat.org
To unsubscribe send an email to pacsat-dev-leave@amsat.org
Manage all of your AMSAT-NA mailing list preferences at
https://mailman.amsat.org

---

pacsat-dev mailing list --pacsat-dev@amsat.org View archives of this mailing list athttps://mailman.amsat.org/hyperkitty/list/pacsat-dev@amsat.org To unsubscribe send an email topacsat-dev-leave@amsat.org Manage all of your AMSAT-NA mailing list preferences athttps://mailman.amsat.org