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ADS7945: Simultaneous sampling with two ADS7945's and a single REF5030

Part Number: ADS7945
Other Parts Discussed in Thread: REF5030, ADS7946

Hello,

I am simultaneously sampling two differential signals with tho ADS7945s sharing a single chip select. I would like to use a single REF5030 to drive the reference input of both ADS7945s, but there is little information about the reference input of the ADC. Is a single REF5030 able to drive two ADS7945 reference inputs?

Thank you,

Sebastian

  • Hello Sebastian,


    The REF5030 is able to drive two ADS7945's simultaneously sampling. I recommend you place a 1uF bypass capacitor in close proximity to the REF5030 output pin and two separate1uF bypass capacitors, one for each ADS7945 device in close proximity to the REFIN pin.

    The TINA transient simulation shows the REF5030 response where the reference voltage droops about ~612uV or ~1.7 LSBs when driving a single ADS7945 during the first 10us of continuous conversion and then recovers.  The reference droops approximately  ~953uV or 2.6 LSBs when driving (2) ADS7945's simultaneously converting.


    Please find attached a zip file with the following TINA simulation files:

    -REF5030+ADS7946 simulation files (2MSPS)

    -REF5030+(2) ADS7946 simultaneously sampling (2MSPS)

    -Original ADS7946 TINA Transient model file with instructions for your reference

    Thank you and Best Regards,

    Luis

    6165.ADS7945_REF5030.zip

  • Thank you for the response.

    Best,
    Sebastian