-----Original Message----- From: Roland Andrag To: PICLIST@MITVMA.MIT.EDU Date: Tuesday, June 09, 1998 2:01 PM Subject: Amplification vs. high res A/D >Hello all... > >This is sort of off topic, but not really, so I didn't include the >OT... Here goes: > >I'd like to get the feeling of the group regarding the input of a >small analogue signal (say 0-100 mV). The choice lies between using a >differential amp to get 0-5 V and using an 8 bit (possibly internal) >A/D to get it into the PIC, or to simply use a 12-bit A/D without >amplification... It depends of what resolution you need. Of course one OP is more cheaper then any 12-bit A/D. What kind of signal? Ehat frequencies? > >For the direct use of a higher res A/D my next question would be >whether A/D converters are available that accept differential inputs >(from a Wheatstone bridge sort of arrangement).. Battery powered, >single supply (0-5 V)... You realy need diff. inputs ? High CMMR ? If it's enough for 80bit internal A/D you can use single diff. OP, see Analog Device's AD620,621, cheaper - AD623. ================================== Alex Torres, Kharkov, Ukraine (exUSSR) E-Mail: altor@geocities.com 2:461/28 FidoNet Home Page: http://www.geocities.com/SiliconValley/Lab/6311