Along with RC filter use 2 diodes for clamping. | Max vtg of ADC input --- /\ - | ----------------/\/\/\/\/-------- | | --- ---- /\ ---- - | | GND | Pailoor - Ross Bencina wrote: > Greetings O PICsters, > > I'm building a device for a friend that has a bunch of external (user > connected) (8 to 12bit) adc inputs (the current design uses a 16f84 and a > tlc542 adc). The box will be used in a "musical" environment. The adc inputs > will be (mostly) powered from the unit itself (ie resistive sensors, light > sensitive transistors circuits etc.). Sensors may be connected using longish > leads. > > As electronics isn't my strong point I'm looking for some advice on > how/whether to "protect" the inputs to avoid having the adc inputs fried. At > the moment I'm planning to connect simple (RC) lowpass filters at each > input. Other than noise I'm not sure what other potential "issues" could > arise (esd etc?), or whether I should even be worried about this in a > non-industrial context. > > Any comments would aid my understanding considerably, > > Thanks, > > Ross. > > > ................................. > http://www.audiomulch.com/~rossb/ -- Website : http://business.vsnl.com/chiptech Content-Type: text/x-vcard; charset=us-ascii; name="vcard.vcf" Content-Description: Card for Ravi Pailoor Content-Disposition: attachment; filename="vcard.vcf" Content-Transfer-Encoding: 7bit Attachment converted: wonderland:vcard.vcf 1 (TEXT/CSOm) (000072FA)