Author Topic: MCF52233 on board a/d  (Read 2993 times)

Offline neil

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MCF52233 on board a/d
« on: February 24, 2011, 06:56:49 PM »
Hi Mark,
   We have an application where we are are reading 2 pt100's where we have a differential voltage. Se we will be using AD0-AD1, and AD2-AD3. We also need 4 single ended inputs so we will use AN4-AN7.  Can this configuration be done?

We will be using an unbalanced Wheatstone bridge (this way we can make sure we get a positive voltage for the range we require) for the pt100, then through an op-amp to get the voltage up. We will also use an external 2.5v reference on all the channels.

Do you see a problem with the above?

Many Thanks

Offline mark

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Re: MCF52233 on board a/d
« Reply #1 on: February 24, 2011, 07:32:52 PM »
Hi Neil

You can configure differential inputs by using ADC_DIFFERENTIAL on channels 0 and 2 (this will automatically configure 0 and 1 as a differential pair and 2 and 3 as the same).

The inputs 4, 5, 6, and 7 can then be used as single-ended inputs.

As long as all voltages are within the analoge range (0..3V) all should be OK.