Alas, I have a fully working supply using the UC3827-1 (buck, current fed). But, I have some alarm circuits that detect faults, and must disable the supply. I was trying to use the SS pin to disable, but it did not. (I eventually resorted to shunting the command voltage to ground, fooling the supply into thinking it had a 0V set point, but that does not work perfectly). So I looked with a scope. The SS pin should use a current source to charge a cap, which is 0.47uF. Alas, no current is coming out of the part, no charge voltage is building up, but shucks, the part starts up and operates anyhow. It is almost like the pin does not go anywhere and does not operate as a SS.
I usually default to assuming that I am missing something.. but I cannot see it!
Anyone know anything about this?
Baffled in Pittsburgh,
Chris~