DS90UB954-Q1: About PDB pin of DS90UB954...

Peter Tseng

Part Number: DS90UB954-Q1

Dear Sirs,

I have a question about the PDB pin.

In the datasheet, the PDB pin must keep more than 1.5V to enable the IC and there is 50Kohm internal pull-down resistor.

However, as the connection below in the datasheet, if connect to 1.8V with 33Kohm, the PDB will be around 1.08V, right?

(voltage divided with 33K and 50K from 1.8V)

This connection will work or not?

Please help to clarify if there is any misunderstanding about it.

Thanks.

0 Shruti More over 3 years ago

Hello Peter,

Yes, you are right, this connection will not work.

Peter Tseng said:
This connection will work or not?

This will be changed in the next datasheet revision. The pull-up needs to be 10K ohm.

Best Regards,

Shruti

0 Peter Tseng over 3 years ago in reply to Shruti More

Hi Sir,

Another question is, what is the PDB voltage range if considered about the divider resistor tolerance, the PDB pin voltage may be lower than 1.5V.

Thanks.

0 Shruti More over 3 years ago in reply to Peter Tseng

Hello Peter,

The PDB voltage Vin high and low, min and max values (for when VDDIO is 1.8V or 3.3V) are shown in the specification tables in the 954 datasheet:

You should make sure that the resistor tolerance results in a voltage within these min and max values.

Best Regards,

Shruti

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