View Full Version : pull up resistors

03-14-2005, 08:03 PM
I am using an at89c2051.I heard that only metal film resistors must be used for pull up..
Why is that :? :? :? Why cant ordinary be used??

03-14-2005, 11:00 PM
I never used metal film resistors on 89c2051 cpus, and they all worked fine.

oh I recall that the RC Reset circuit of 89c2051 should have R>= 50K.
usually we use 10K in all other 51 family cpus.

please confirm from datasheet and use R>=50K i.e 62K or so.
Otherwise in some cases the cpu stops working after an hour or so. :)