Post Go back to editing

signal attenuation of AD5290

Product Number: AD5290

Hi,

I want to use AD5290. 

Could you confirm following question.

- Could you teach me signal attenuation in dB when used in divider mode with the wiper set to minimum?
  I would like you to provide the typ value and, if possible, the max value. Because I would like to control the audio volume that it needs to be attenuated by -60dB or more.
  https://www.analog.com/jp/analog-dialogue/articles/digipot-specifications-and-architecture.html

Best Regards

  • Hi,

    What do you mean when you say divider mode? Is it in potentiometer mode? Also, what terminal is connected to the supply and the other to ground?

    In this configuration:

    The transfer function is  \frac{Rwb}{Rab+Rw}

    Using 100k Rab, if i'll be considering the max Wiper resistance (100 ohm) and terminal B connected to GND, then the attenuation in dB is -50dB when the wiper is set to minimum.

    Using 100k Rab, if i'll be considering the typical Wiper resistance (50 ohm) and terminal B connected to GND, then the attenuation in dB is -56dB when the wiper is set to minimum.

    When considering +30% tolerance and 50 ohm resistance, the max attenuation is -58dB.

    You can use a 1Mohm digipot to reach -60dB and below in this configuration or you can stack digipots, whichever is more suitable for your application. Here's an application note about stacking, cascading or parallel multiple digipots. Pote (analog.com)

    n

    Best Regards,

    Yokki

  • Hi,

    Thank you for your support.

    >What do you mean when you say divider mode? Is it in potentiometer mode?

      - I think potentiometer mode like P16 on datasheet.

    Thank you for your information about following.

    >Using 100k Rab, if i'll be considering the max Wiper resistance (100 ohm) and terminal B connected to GND, then the attenuation in dB is -50dB when the wiper is set to minimum.

    >Using 100k Rab, if i'll be considering the typical Wiper resistance (50 ohm) and terminal B connected to GND, then the attenuation in dB is -56dB when the wiper is set to minimum.

    >When considering +30% tolerance and 50 ohm resistance, the max attenuation is -58dB.

    Best Regards