ADC problem!

aialinux · ‎2006-02-12

Posted on February 13, 2006 at 06:32

ADC problem!

aialinux · ‎2006-02-12

Posted on February 12, 2006 at 22:03

I am using the ADC in STR710 chip. When P1.0 is 1.00V

I want to know the converted value stored in ADC_DATA[0].

The STR710 ADC is different to other MCU.

I am not so clear to it's principle.

How to calculate the converted value when AIN0 has voltage 0--2.5V.

[ This message was edited by: dom on 13-02-2006 02:34 ]

hichem2 · ‎2006-02-12

Posted on February 13, 2006 at 06:32

Hi dom,

While the analog modulator is critically important in determining accuracy of a sigma delta ADC, digital software calibration techniques are essential for reducing offset and gain errors, as well as improving linearity.

The converted value stored in ADC_DATA[n] is a signed twoâ€™s complement.

To calibrate the converter, itâ€™s necessary to apply the minimum and maximum inputs supported 0V and 2.5V. The digital output for a 0V input is the offset.

The offset and gain correction factors calculated by software can be stored digitally and applied to all outputs from the converter.

Note: You can find with the STR71x software library package (available on the web) an example of how to use the STR71x ADC 12 converter in single channel mode.

Regards,

Hichem