SDADC problem in single-ended mode.

txmsszd · ‎2016-09-04

Posted on September 04, 2016 at 10:02

Hi,

I meet a problem with my project in which a STM32F373 MCU is used to collect singnal in single-ended mode.I short the pin with GND to test the board,the ADC values I get seems to fluctuate like saw-tooth.

The graph above shows what I get with my board.The signal is moving averaged.

But if I chang SDADC module into differential mode,the saw-tooth liked pattern disappears.

The single passes through a RC network before it arrives at the SDADC pin.

Has anyone encountered such a prolem?

Thanks

txmsszd · ‎2016-09-06

Posted on September 07, 2016 at 03:00

What you said makes sense to me after some calculation.I decide to use it in differential mode,but the available channel seems finite,only 11 channel?

The evaluation board of ST has been referred in the process of schematic designing. The datasheets of LDOs mentioned above are consulted for analog power supply circuit. The circuit schematic could not be provided due to some restrictions,sorry for this.

Many thanks,markt. Your kindly and patient explanations are highly appreciated.

Best regards.