Hi Stefan,
on our board some DRS chips draw a lot of current through DVDD after power-up and heat up significantly--it is true that our board doesn't have weak pull-down resistors at DENABLE and DWRITE output pins of FPGA, so this problem might have been caused by that, but a reinitialization of the Domino circuit doesn't help either. We tried different capacitors at DVDD and it seemed the larger the capacitance, the better the result--with a capacitor larger than 10nF some of the DRS chips could work happily in the normal way while if the capacitor is only 4.7nF all of them got very hot. Would you please provide some suggestions why there should be such a problem?
Thanks a lot! |