Hi Dave, Good to hear it works. First of all: the PSU decoupling (100n close to each chip) is mandatory for digital circuits to work reliable.
The input current of 23k246 can be neglected. Speed is determined by the feed resistance and the capacity of the circuit (that is: input capacity of the chip, but also of traces). Long wires do add extra capacity (and induction, to make it even worse). It is hard to predict the real capacity and thus the max resistance allowed for a certain speed. In practice, an oscilloscope can be used to determine if the signal is good enough. Regards, Joep 2012/9/11 PDSACAA <[email protected]>: > > Matt/Joep > A result!! > > Changed the CLK resistor network to 1k/2.2k (didn’t have 2k don’t ask why) > > Assuming PIC output level of 5V, divider would give 3.44V (ish) which was > within 23k256 spec of Vcc (3.3V ) + 0.3V max. input. > > Obtained perfect results no problems reading/writing large byte values. - > yippee!! > > Showed that 23k256 had not appeared to have suffered any damage from my > fumbling. > > Think I will stop there and call a halt on the 74HTC08 alternative method > for now. > > Looks as though comment by Joep "larger current faster signals" did the > trick. > > Where would one look on the 23k256 data sheet to assess the clock current > sensitivity? > > If you find out why will you let me know? > > Thanks for help with this > > Kind Regards > > Dave > > > > > -- > You received this message because you are subscribed to the Google Groups > "jallib" group. > To view this discussion on the web visit > https://groups.google.com/d/msg/jallib/-/eA8MlKwUm30J. > > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/jallib?hl=en. -- You received this message because you are subscribed to the Google Groups "jallib" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/jallib?hl=en.
