AnsweredAssumed Answered

AD7709 CONVERTER PROBLEM

Question asked by Michael-C-L on Nov 18, 2013
Latest reply on Nov 27, 2013 by Michael-C-L

Hi,

i use an ad7709 to measure thermocouple signal, and there is a problem:

conditions:

1. input channel:AIN1 and AIN2.

2. use pseudo-bipolar mode.

problems:

1. when i operated as follow process:

     hardware reset (use reset pin ) --> read first data --> read second data --> end

     then, both datas were wrong.

2. when i only read one data,

     hardware reset --> read first data --> end

     then, the data was right.

so why?

 

and i also have some questions:

1. do i need to calibrate the product after manufacture?

     i read datasheet that, the device is factory-calibrated at final test. however, we will use different voltage reference, is that still ok?

2. do i need to care about zero shift?,

     in most ad converters, this is a serious problem, so is it same with this device?

 

Thanks.

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