mikec@wheaties.ai.mit.edu (Mike E. Ciholas) (05/04/90)
In article <8222@rice-chex.ai.mit.edu> mikec@rice-chex.ai.mit.edu (Mike E. Ciholas) writes: >In article <11220003@hpccc.HP.COM> wille@hpccc.HP.COM (Ross Wille) writes: >>Shouldn't the A/D converter have a sample & hold in front of it? Since >>it is using successive approximation, the input should be stable during >>the entire conversion time. Maybe the A/D has a built-in S&H but I'd >>think not. Maybe it just works well enough with out one. Anybody know? >> >>-Ross >The ADC0831 has a sample and hold on it, when the conversion start pulse >comes, it samples for one high period of the conversion clock, then >ignores the input. Very nice chip, all in all. > >Mike Ciholas WHOOOPS! Sorry about that, I am wrong. The NATIONAL ADC 0831 has no sample and hold, which is bad. HOWEVER, MICRO-LINEAR's ML2281 does have a sample and hold that works as described. That is where I got the info. (the micro linear chip is pin and functional compatible, but offers a sample and hold and faster conversion timing). I'll see what I can get the chips for. If they don't cost much if any more than the national, then I'll get those for the kits. Mike Ciholas email: mikec@ai.mit.edu snail: 289 Highland Ave, #108/Somerville, MA 02144 phone: (617) 623-3563 air: N1909C, 1954 Cessna 170B