italie |
MAME owes italie many thank yous, hah
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Reged: 09/20/03
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Posts: 15246
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Loc: BoomTown
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Re: HELP:Measuring refresh rate of PCBs
01/04/11 08:40 PM
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> > Floating values could be a function of the PCB, tthe quality of the input signal, > the > > connections, the impedance/capacitance of the probe wire, improper > > coupling/grounding...etc. > > > > If you don't have access to a scope, I'd start by filtering the input pin as shown > on > > page 7 (below) with a 620 Ohm resistor and a 510pf capacitor to make sure your > imput > > is clean. > > > > http://www.national.com/ds/LM/LM1881.pdf > > Ok thanks, I'll try filtering the input..but capacitors must be polarized or normal > ceramic?
Ceramic is fine.
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