The OPT8241 SUB_BIAS Pin Can directly connect to 0V all the time?

Hi Bharath,

Thanks for you information!

Hi Bharath,

I want to know when SUB_BIAS voltage is setting to -5V, How much better than setting SUB_BIAS voltage to 0V. In our new design we want to remove the LMR70503 circuit. I'd like to think you should have do the experiment.

Thanks.

Hi Bharath,

if you feel convenient,please help me to solve the problem above this.

Thanks&Regards

None

Hi,

It is ok to connect SUB_BIAS to 0V all the time. Improvement due to use of negative bias depends a lot on operating conditions (Probably about 10-30% better depth resolution depending on Modulation frequency, VMIXH voltage. Improvement is more noticeable at modulation frequencies greater than 40MHz). It is best to use an option for negative voltage SUB_BIAS during prototyping. Once the operating conditions are fixed, you can do two expts -

- Turn on SUB_BIAS, take a note of the performance (standard deviation of phase at a fixed distance)

- Turn off SUB_BIAS, record performance again.

Compare the two performances and decide on whether you need SUB_BIAS. If you don't need it, you can DNP (Do not populate) the parts when you do the production version.

Regards

Hi Bharath,

thanks for you reply.

Regards.