2013-03-11 06:13 AM
Hi
We figured out some ADC channel miss match on STM32F100C8 device, which we couldn't explane. We use the following test setup: - ADC1_IN0 (PA0) to ADC1_IN3 (PA3) are used. - Regular group scan mode with DMA is used. - VDDA = 3.300V is used as reference. - All for channel are connected together to a OP buffer as common source. - ADC cloch 12MHz with 55.5cycle sample time. We got the following test results: - ADC channel nois is fine +/- 1LSB. - ADC1_IN1 is fine +/- 1 LSB compared to measured input voltage. - All other channels are void -10LSB compared to measured input voltage. - Changing the order within the regular group sequence had no influence. - Incresing the sample time to 239.5cycle had no influence. - Disconnecting ADC1_IN0 had no influence (To avoid voltage glitch related to the errate sheet) - Reducing the ADC clock to 1.5MHz had no influence. Thasnk for any help in advance. Raphael #adc2013-03-11 09:47 AM
Hi
Only channel ADC1_IN1 was initialized proper. All other channels were still initialized as digitial input with pull down enabled. Best regards Raphael