In order to decrease the range of the ADC (I'am using the Highspeed AD/DA Card hsmc model) we found in the data sheet of the adc manufacturer that you simple need to reduce the supply voltage.Is there a proper way of doing so? -By configuring the fpga? -By using an external high precision voltage source? if so how do I connect them? Best regards, Bert.
Hi Bert, could you please help clarify your query first, you'd like to change the power supply? Or modify the reference voltage?In addition, please indicate the source/content of what you described regarding ''found in the data sheet of the adc manufacturer that'', so that I can assist in right way. Nikita, Terasic
Thanks for your reply.In order to clarify: *)Basically the thing i trying to do is decreasing range to increase resolution: (this was maybe not correct mentioned in my introduction post sorry for that) *)In the datasheet of the manufacture (http://www.analog.com/media/en/technical-documentation/data-sheets/ad9248.pdf) of the adc chip is mentioned the following --- Quote Start --- The input span of theADC tracks reference voltage changes linearly. If the ADC isbeing driven differentially through a transformer, the reference... page 20 of 48 --- Quote End --- so I suppose the by varying the source voltage I'm able to change range (and so to change resolution more bits for less voltage => I would like to use them with smaller signals) The question is now can I do did in a proper way on the Highspeed AD/DA Card board? (http://www.terasic.com.tw/cgi-bin/page/archive.pl?language=english&categoryno=67&no=278) Best regards. Bert.
Hello,sorry for the long delay how ever let me explain: -We would like to increase resolution and thererfore decrease the range> (also wrongly mentioned in first post i'm sorry for that) -in the data sheet ( http://www.analog.com/media/en/technical-documentation/data-sheets/ad9248.pdf ) --- Quote Start --- The input range can be adjusted by varying the reference voltage applied to the AD9248, using either the internal reference with different external resistor configurations or an externally applied reference voltage --- Quote End --- Now my questions is can we vary this reference voltage in a proper way in the Highspeed AD/DA Card hsmc model? Best regards, Bert.