ADS8588H: Errors for sinusoidal signal of 2 kHz

Lars Hummel

Part Number: ADS8588H

Hello,

I am using the this ADC for a 6-wire LVDT interface that uses an 2kHz (+-10%) Excitation signal. The requirements are very high with 0.07% absolute accuracy

In Figure 55. "Third-Order LPF Magnitude Response" the Butterworth Low-Pass-Filter shows a magnitude damping of aprox -1 dB an a non-linearity just between 2 and 3 kHz.

1. Does this mean that my input signal is also damped by 1dB?

2. How do I take the non-linearity of this Butterworth LPF into account if my excitation f shifts to this non-linearity region?

3. Where can I optain the errors of the ADC on the amplitude for my 2kHz (+-10%) signal? Just from the errors gain/offset/non-linearity?

Thanks in advance

Regards

Lars

over 2 years ago

0 Dale Li over 2 years ago

TI__Mastermind 37190 points

Hi Lars,

For the magnitude of LPF in Figure 55, the “-1 dB” axis point in the graph should be updated to indicate 0 dB. The datasheet should be updated. I apologized for the confusion to you.

Regards,

Dale

0 Lars Hummel over 2 years ago in reply to Dale Li

Prodigy 155 points

Hello Dale,

Thanks for your feedback.

I have to know the influence of the ADC-internal Butterworth filter for a 2kHz signal - specially what damping has this filter on a 2 kHz signal. Is there data (damping-values over frequency or arround 2kHz) or other data (Butterworth - Parameters e. g. R- and C-Values) available?

Thanks in advance

Lars

0 Dale Li over 2 years ago in reply to Lars Hummel

TI__Mastermind 37190 points

Lars,

Let me check if I can find something, I will get it back to you soon.

Regards,

Dale

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ADS8588H: Errors for sinusoidal signal of 2 kHz