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ADS7253 Reference

Other Parts Discussed in Thread: ADS7253

Hi,

Question in the Reference of ADS7253.
When 2.5V reference using the device internal reference, and then question in REFIO_A and REFIO_B of connection method.

Data Sheet (SBAS584B) page29 Figure84 10uF capacitor between REFGND_x and REFIO_x In is connected.
But,EVM application note(sbau210a) page34 in REFGND_x and REFIO_x between connected by 10uF + 0.1Ω.

Or should I either of the circuit to the reference?

Best regards

  • Hi Cafain,
    The capacitor(10uF) affects the stability of the driving amplifier, therefore a series resistor is recommended to isolate the amplifier output and make it more stable. The value of resistoris depends on the output impedance of the driving amplifier as well as on the signal frequency. The typical values of this resistor range between 0.1 Ω to 2 Ω and the exact value can be found by using SPICE simulations. It is recommended to use the smallest possible values to avoid any voltage spikes at the reference pin, which can potentially affect the conversion accuracy.
    Hopefully this is helpful for you, thanks.

    Regards
    Dale
  • Hi,

    As a characteristic of the op-amp, I understand that it can not be obtained, the phase margin in the capacitive load drive.
    This time using the internal reference, to how to connect the capacitor of 10uF between the terminals.

    I appreciate your support.