ADS5294: Analog input

Hi,

Thanks for using ADS5294 device.

Yes, when you are going to input signal with DC coupled,

please first look at the ADS5294 datasheet page 30 and Figure 44.

It shows that you need to use ADS5294 VCM pin 68 to keep your input signal

common-mode as (about 0.95V). Also you can use this page 30 to estimate

to match your input impedance with ADC input circuitry.

Also please look at the ADS5294 User's Guide page 27 Figure 20 as reference

(for example, use THS4509 with its CM set to VCM from ADS5294.)

Thank you!

Hi,

If you are concerning very low input frequency purpose,

yes, it is better to use DC coupled input,

could you please let me know how low the input signal you try to run?

because you can see from ADS5294 datasheet page 27 Figure 38,

you may need to set LF noise suppression Enable.

Thank you!

Hi,

for setting the Low Frequency Noise Suppression Enable,

please set the register Address=0x14, also please refer to ADS5294 Datasheet Page 40 Table 6

and Page 46 Table 8.

Also assume your Sample Rate is set as 80MSPS,

then also please refer to datasheet page 27 Figure 38 and Figure 39.

Those frequency range can fit your signal bandwidth range.

Thank you!