Silas

Wrong ADC conversion value (STM32H743)

Discussion created by Silas on Mar 13, 2018
Latest reply on Mar 16, 2018 by T J

Hi,

 

I'm using channel 2 in Single-ended mode of ADC1 of STM32H743II. The VREF+ pin is connected to an external voltage reference of 2.048V. VDD and VDDA is supplied by differents  LDO of 3V. The clock of ADC is 100MHz and the prescaler is 8: fADC=12.5MHz. The STM32CubeMX ADC1 config is attached.

 

When the conversion is triggered by software, the interrupt is generated as expected. The DR register values for some input voltages follow below:

 

96.8mV -> 2559 (0x9FF)

72.6mV -> 2047 (0x7FF)

48.4mV -> 1023 (0x3FF)

24.2mV -> 511 (0x1FF)

12.1mV -> 127 (0x7F)

4.8mV -> 111 (0x6F)

 

 

How can I solve this issue?

 

Thanks,

Silas

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