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ADS1220: Search for analog power supply ADS1220

Matteo
Prodigy 115 points
Part Number: ADS1220


Tool/software:

Hello,

I am looking for a supply with a Vout of 3.3 V for the AVDD of the ADS1220 ADC. Currently, I have Vin = 24 V, from which I derive the 3.3 V for the entire PCB using a switching converter.
The digital and analog grounds are not separated. For the AVDD of the microcontroller, which is not critical, I use a ferrite bead and the same 3.3 V for the digital part. However, for the external ADC, I  think it would be better to have a cleaner power source, or not?

Thank you,
Matteo

  • 0
    TI__Mastermind 46425 points

    Hi Matteo,

    Yes, a clean and low noise power supply is recommended for the standalone ADC, especially AVDD. The ripple and noise on the AVDD power supply will lead to an error on your measurement.

    BR,

    Dale

  • 0 in reply to Dale Li
    Prodigy 115 points

    Hi Dale,

    Thank you for your reply.

    Can you recommend me an LDO for AVDD (ADS1220)?
    I want to power the analog section with 3.3 V.
    Since I only need to power this ADC, a voltage reference or an ultra low dropout regulator might also be suitable. Could I potentially use the 3.3 V for DVDD as a source for the regulator?

    Best regards,
    Matteo

  • +1 in reply to Matteo
    TI__Mastermind 46425 points

    Hi Matteo,

    We usually use TPS7A4700 but it can delivery 1A maximum current. TPS76333DBV was designed on ADS1220EVM, you can find it in the EVM user guide. You can post on TI power Management forum to see if TI power team has any new-gen LDO with low noise and high PSRR or any other recommendation. You can find the power supply requirement on ADS1220 below:

    BR,

    Dale