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ADuCM3029 ADC Detail Questions - Timing, Input and Consumption

Question asked by felipe.murcia on Jan 22, 2018
Latest reply on Jan 24, 2018 by Narsimh

Hi,

  1. I'm considering using the ADuCM329 for an ultralow power application that requires a slow sampling rate of 500Sps, I believe the documentation says single channel single conversion is possible but for SPS lower than 10Ksps dummy conversions are needed (at a 100us delay max). This dummy conversions have to be the full ADC working or could they just reading the ADC output data register (or memory address)? I mean do I actually have to set the  ADC_CNV_CFG.SINGLE bit with a maximum delay of 100us? 
  2. What is the capacitance of the sampling circuit of the ADC? Do you have an equivalent circuit diagram so that I can estimate the required characteristics of an external buffer and the sampling time? I can't seem to find this information anywhere. 
  3. After the sampling phase of the ADC how much does the conversion phase last? Is there a rough estimate in terms of PCLK or ADCLK cycles? 
  4. The current estimation in the datasheet says that for a 100KSps and 1KHz input signal the current consumption is 104uA (with 1.8 supply) through VBAT_ADC while the ADC is doing a conversion. Is this the current in the "sampling + conversion phase" only or is it a mean consumption in those conditions?  

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