DS90UB936-Q1: Internal pull-down/pull-up when PDB=L or H for UB936 and DS90UB947

Atsushi Hirai

Part Number: DS90UB936-Q1

Hi team,

My customer is reviewing the state of internal pull-down and pull-up during reset and normal operation.

Could you fill below list out with all pins which have internal pull-down/pull-up for UB936 and UB947? I think there is no Pull-up in these devices. Please correct if it's wrong.

DS90UB936

PDB=Low

Pull-down:

Pull-up: Nothing

PDB=High

Pull-down:

Pull-up: Nothing

DS90UB947

PDB=Low

Pull-down:

Pull-up: Nothing

PDB=High

Pull-down:

Pull-up: Nothing

over 4 years ago

0 Nicholas Darash over 4 years ago

TI__Mastermind 18755 points

Hello,

For the 936 there is an internal pull-down resistor of 50kOhm, as for the 947 it has an internal pull-down resistor but it will take some time to find the value of the resistor.

Regards,

Nick

0 Atsushi Hirai over 4 years ago in reply to Nicholas Darash

TI__Expert 4970 points

Nick-san,

What I asking is not only for PDB pin but also all other pins.

We can wait for a few days. Please check it. Thank you for your support.

0 Nicholas Darash over 4 years ago in reply to Atsushi Hirai

TI__Mastermind 18755 points

Hello,

Can you be specific about which pins you want details about. I don't have this information readily available and it may take many hours to dig into the design database to get this info. I would just like to know exactly what we are looking for before we agree to take on a huge endeavor like this.

Regards,

Nick

0 Atsushi Hirai over 4 years ago in reply to Nicholas Darash

TI__Expert 4970 points

Nick-san,

Understood.

But customer needs all pins because this is review.

Could you check only the existence of pull-up/down and if it’s available in both PDB=H and L?

Regards,

0 Nicholas Darash over 4 years ago in reply to Atsushi Hirai

TI__Mastermind 18755 points

Hello Atsushi,

This still would take some time for us to dig this up. Why is this information necessary? For review they should make sure they are following the recommendations listed in the datasheet.

Regards,

Nick

0 Atsushi Hirai over 4 years ago in reply to Nicholas Darash

TI__Expert 4970 points

Nick-san,

The main reason is because our datasheet doesn't clearly mentions the state of internal pull-up/down during PDB=L. Customer have to understand how to behave all pins during both PDB=H and L to avoid unexpected state for connected devices with UB936, 947.

This is the maximum compromise. Please support.

0 Nicholas Darash over 4 years ago in reply to Atsushi Hirai

TI__Mastermind 18755 points

Hi Atsushi,

Let me check with my team to see what we can do here. I don't think getting the resistor values for each pin is realistic though.

Regards,

Nick

0 Atsushi Hirai over 4 years ago in reply to Nicholas Darash

TI__Expert 4970 points

Nick-san,

Got it. Thank you for your support.

I'll wait your next response.

0 Nicholas Darash over 4 years ago in reply to Atsushi Hirai

TI__Mastermind 18755 points

I will let you know what I can find.

Regards,

Nick

0 Nicholas Darash over 4 years ago in reply to Nicholas Darash

TI__Mastermind 18755 points

Hello,

This information is not readily available and I cannot take resources away from the designers to dig this all up. All we can provide is the information that is given in the datasheet. It would potentially be weeks of searching through old design files and running simulations and even then I could not guarantee how accurate they would be.

Regards,

Nick

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DS90UB936-Q1: Internal pull-down/pull-up when PDB=L or H for UB936 and DS90UB947