ADS8684: 由于加了RC滤波导致的读数如何补偿？

Zoe Yang

Part Number: ADS8684

Dear Dale,

我的客户在用ADS8684的时候由于前级输入信号有一些干扰，所以在输入的这里加入了RC滤波滤掉信号噪声。如图所示，R=20k, C=0.01uF. 但是这样的配置导致增益有偏差，之前增益设定为1，加入RC滤波增益偏移20%。请问这种情况下如何通过读数来补偿这种增益偏移带来的误差从而回归到读取出真实值？

感谢您的答复！

over 3 years ago

0 Dale Li over 3 years ago

TI__Mastermind 45745 points

Hi Zoe,

To compensate the additional gain error at room and full temperature range, the customer will have to do periodic calibration. This is not realistic for most customers. The cutoff frequency of external RC filter in your customer's design is only 796Hz which is really low. There are few ways to improve the error on the system level:

Reduce the resistor value and increase the capacitor value.
Select a lower tolerance high precision and low temperature drift resistor.
Do gain and offset calibration at room temperature before sampling analog signal.

Best regards,

Dale

0 Dale Li over 3 years ago in reply to Dale Li

TI__Mastermind 45745 points

This thread was closed because communicated in emails.

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ADS8684: 由于加了RC滤波导致的读数如何补偿？