ADS1299EEGFE-PDK: The BIAS_DRV option also helps in improving common mode rejection by implementing a feedback loop

yong liu

Part Number: ADS1299EEGFE-PDK

Dear TI Engineer:

I tried two sources for BIAS_DRV you mentioned in last related question, that is BIASREF_INT be set 0 or 1.

I found that these two ways has roughly equivalent common mode rejection function for 50Hz sine wave.

At the same time, I read in slau443b page 34 that, The advantage of using BIAS_DRV signal is that it takes advantage of feedback loop to get better common mode rejection.

Now is my question, is "BIASREF_INT be set 1" way tests much more better or just a little better?

2 个月前

0 Lydia 2 个月前

TI__Mastermind 29185 points

您好，

已经收到了您的案例，调查需要些时间，感谢您的耐心等待。

0 yong liu 2 个月前回复 Lydia

Prodigy 10 points

如果能得到您及时有价值的回复，我将会感到非常的感激。

0 Lydia 2 个月前回复 yong liu

TI__Mastermind 29185 points

您好，

已经帮您升级处理，但是目前还没有得到回复，会再次帮您催促，请您耐心等待。

+1 Lydia 2 个月前回复 yong liu

TI__Mastermind 29185 points

Hi,

The CMRR improvement with the BIAS amplifier circuit should be equivalent when using either internal or external BIASREF voltage. BIASREF is simply the DC bias voltage required to shift the body's bio-potential signals to be within range of the analog front-end. Typically, this voltage is near mid-supply (AVDD+AVSS) / 2.

For evaluation, the customer can ignore the U11 circuit footprint. This was included for the purpose of evaluating a discrete amplifier as a BIAS driver, but I do not know of any customers who use this.

Ask the customer to remove the jumpers from JP6 and JP1. The bias electrode can be connected to JP1 pin 2.

Regards,

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ADS1299EEGFE-PDK: The BIAS_DRV option also helps in improving common mode rejection by implementing a feedback loop