econ Posted November 21, 2005 Report Share Posted November 21, 2005 I tried to use ADC0832 instead of ADC0832. The problem is that, internally Vref is tied in Vcc pin of the ADC0832; I just want to use this IC so that the volatge input range should be in 1.6-4.2V or any range below 5V, instead of the usual 0-5V. I can't figure out how to do this? Any Ideas! Quote Link to comment Share on other sites More sharing options...
EdwardM Posted November 21, 2005 Report Share Posted November 21, 2005 Hi econthere is an excellent introduction to opamps, particularly chapter 4, which will help to solve your problemBest of LuckEdhttp://homepage.mac.com/tbitson/weather/TI_OpAmp_Tutorial.pdf Quote Link to comment Share on other sites More sharing options...
ante Posted November 23, 2005 Report Share Posted November 23, 2005 I am sorry but I have to ask: Isn’t ADC082 an A/D Converter, not an op amp? Quote Link to comment Share on other sites More sharing options...
MP Posted November 24, 2005 Report Share Posted November 24, 2005 econ,You do not have to use 5V. Nor do you need to vary the reference voltage. It is fine. The analog voltage will give you a number which represents the input. It is capable of a DC voltage between 0 and 5 volts. You do not need to use the full scale voltage. After you get a digital number, it is only a matter of math.I think that Edward was suggesting that you use an op-amp circuit to vary the zero and span of the analog voltage. This would allow you to re-scale it. But unless the resolution is critical, you can just use the input that you mentioned with no additional hardware. MP Quote Link to comment Share on other sites More sharing options...
EdwardM Posted November 24, 2005 Report Share Posted November 24, 2005 Thanks MPthat's exactly what I was suggesting but in reading over what I've posted, it does need more detail. However I did take econs' question literally and pointed to one possible way to solve the problem.Ed Quote Link to comment Share on other sites More sharing options...
MP Posted November 26, 2005 Report Share Posted November 26, 2005 It is a good suggestion, Edward. It is possible that econ needs the resolution. Hope you didn't take my post out of context. I just wanted to add to it as it seemed econ was confused about the operation of the ADC and others were confused what you meant by using op-amps.Talking about confusion...my biggest confusion was the first line in the first post...."I tried to use ADC0832 instead of ADC0832." ??? Aren't these the same chip?MP Quote Link to comment Share on other sites More sharing options...
econ Posted December 4, 2005 Author Report Share Posted December 4, 2005 Tnx for the ideas. It was just a typo. error. I mean "Use ADC0832 instead of using ADC0831". Since ADC0831 has a separate pin (Vref) and ADC0832 integrates both the Vcc and Vref, the real problem is that how to change the usual resolution from 0-5V, to 1.5-4.16 for an instance. Tnx for the suggestion! Quote Link to comment Share on other sites More sharing options...
login
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.