ADUCM361 sampling frequency with single conversion mode and multi channel

Hi,

We are using ADUCM361 in our project. We have below queries. Please claify

1. What is the maximum ADC sampling frequency, if the ADC is configured with single conversion mode and switching between 2 channels. (Example: Conigure ADC to read channel 1, wait for conversion complete interrupt, Configure ADC to read channel 2 and wait for the conversion to complete, repeat). 

2. During the single conversion mode ADCxFLT configuration and fADC (As given in table 16 and 30 of the UG-367) is applicable?  or this is applicable only for the contineous conversion mode?

Thanks & Regards,

Vinay

  • I have moved this question about ADuCM361 to the (+) Q&A - Precision Microcontrollers - EngineerZone (analog.com) community.  Someone here should be able to assist you.

    Thanks,

    Jellenie

  • Hi,

    1) Switching b/w channels take negligible amount of time.

    ADC sampling rate with 50/60Hz notch on= 50sps in continuous conversion mode

                                   = 16.67sps in single conversion mode

    2) Tables 16 and 30 are applicable for both singe and continuous conversions.

  • Hi Akila,

    Thanks for the inputs. Based on your comments, I have below queries.

    Currently our ADUCM361 Configuration is as follows

    Mode - Single conversion

    Channels used - 2 (Switching between two  channels -> configure ADC to read channel 1, wait for conversion complete interrupt, Configure ADC to read channel 2 and wait for the conversion to complete, repeat)

    PGA Gain - 1

    Filter configuration for both channels is as below

    AF - 6

    SF - 3

    CHOP - Enabled

    RAVG2 - Enabled

    SINC4EN - Disabled

    NOTCH2 - Enabled

    Based on the above configuration and based on the calculation given in the table 16, the sampling frequency should be nearly 215Hz for each channel, but actually we are getting the sampling frequency of 50Hz for each channel. 

    Note: Sampling frequency is the rate at which we are getting new data ready interrupt. 

    Could you please analyze this and let us know how we are getting the 50Hz? 

    Also, in your previous statement, you mentioned with single conversion mode with NOTCH on, the sampling frequency is 16.6Hz, but we are getting around 50Hz. Could you please clarify this?

    Thanks & Regards,

    Vinay