I'm considering to buy CN0172 (EVAL-CN0172-SDPZ + EVAL-SDP-CB1Z) to measure the temperature for my research, but I need to know the exact maximum data acquisition frequency of this device at first.
Could anyone help me with this question?
Hi Julia, the CN0172 is based on the AD7793 ADC, which has a programmable data rate of between 4.17 samples / second and 470 samples / second. Note that if you are reading multiple channels, you will need to consider the settling time, which is listed in the AD7793 datasheet, Table 16.
many thanks for your kind reply. I'm new to the electrical device, I don't know the relationship of the frequency, the settling time and the number of channels. It is possible that I read two channels simultaneously under the frequency of 470Hz, will it cause some problem?
Hi Julia, sorry for the delay. The AD7792 is a multiplexed device, it cannot sample simultaneously. According to Table 16, it looks like the effective sample rate when reading multiple channels is 1/(4ms) = 250 samples/second, and this sample rate gets distribuited across the number of channels you are measuring, that is, you will get 125 samples/second per channel.
Do you just need a single unit to measure temperature for your project? Are you new to electrical device in general, or this ADC in particular? Either way, there are lots of subtleties, and once you get over any hardware issues, the CN0172 software may not be able to do what you need. You might be much better off buying something off the shelf, there are low cost options from companies like Dataq, Madgetech, others, that are intended for use as a piece of test equipment, rather than a reference design.
1) if your objective is to measure temperature and you only need one (or a small number) of instruments: Better off buying something off the shelf.
2) If your objective is to design and manufacture temperature measurement equipment and you intend to make and sell lots of instruments, using CN0172 as a reference design, let's continue this conversation.