TPS7B7702-Q1: Single Channel Usage

Hi Mayur,

I am looking into whether SENSEx can be left floating to be sure, but I think it is fine to leave it floating. Please allow me 1-2 business days to get back to you with a more definitive answer.

Unfortunately there is no P2P alternative for this device.

Regards,

Nick

Hello Nick,

Thanks for the reply.

Along with SENSEx, kindly consider the following pins also: EN2, SENSE_SEL, LIM2, FB2, OUT2.

Thank you.

Hi Mayur,

For the other pins, please see this other post I supported a while back. 

Regards,

Nick

Hello Nick,

Do we have an answer on the effects of leaving pin SENSEx open?

Hi Mayur,

The designer is going to look at the schematics today. I think it is fine but just want to be sure.

Thanks,

Nick

Hi Nick,

Thanks for the reply

Hello Nick,

I had one more query. 

We are using TPS7B7701, we are using Pin No 5 i.e. Sense for sensing and Pin No 7 is left NC.

Now if we plan to use TPS7B7702, if Pin 7 is left NC i.e. SENSE_SEL, is there any way to get the Sensing through Pin 5 keeping Pin7 open?

Hi Mayur,

Why not tie the NC pin for TPS7B7701 to the potential (i.e. GND) that would set the dual channel device SENSE1 status to output the channel 1 status? To be more clear, if you tie pin 7 (NC for TPS7B7701 and SENSE_SEL for TPS7B7702) to GND, this will configure SENSE1 for the TPS7B7702 to output the channel 1 status, and the TPS7B7701 is not affected because pin 7 is not internally connected anyways. 

If you leave pin 7 floating, the SENSEX pin status is indeterminate because the logic level is unknown.

Regards,

Nick

Hi Nick,

Yes this will solve the issue, but however with current layout feasibility, we don't have an option to tie pin 7 to GND as it is NC. Hence we are looking into the possible issues that can arise out of using the dual channel LDO instead of single channel LDO.

Hi Mayur,

Gotcha, I thought you were in the design phase. 

In that case, I am trying to see if there is an internal pull-up/down circuit to keep SENSE_SEL in a known state when it is not externally biased. I'll update you when I have more info.

Regards,

Nick

Hi Nick,

Thank you for the reply.

Are there any updates?

Hi Mayur,

I'm sorry, I was waiting on a reply and I forgot about this. I pinged the designer again to take a look at this.

Regards,

Nick