DS90UB933-Q1: DS90UB933 port capacitance at data input from image sensor

Hi Kuramochi-san,

Thanks for your inquiry. As you found in the datasheet we do not specify the pin capacitance of the pins which you listed. Are you looking for a method to simulate the I/O behavior of the DS90UB933? If so, I would recommend taking a look at the IBIS model for this device which is included in the product page on TI.com. 

Best,

Thomas

Hi Thomas-san,

Thank you for your reply.
I understand you suggest them to use IBIS model to confirm signal integrity.

But pin capacitance is better to roughly estimation.
Then do you provide roughly estimated capacitance for each pin from the point of view of IC design?
We don't require guaranty for this answer and we'd like to know it for reference only.

Sorry for bothering you but I'm waiting your answer.

Thank you and best regards,
Kazuki Kuramochi

Hi Kumamochi-san,

After looking into this a bit more we do not have pin capacitance values available for the DS90BU933. The best alternative which we could provide is the IBIS model for I/O simulation.

Best,

Thomas

Hi Thomas-san,

I broke down IBIS model on TI.com.
Then pkg and those pin's capacitance is as follows.

pkg = 0pF
DIN[0,1] = 1.107pF(typ)
DIN[2:11] / HSYNC / VSYNC = 1.615pF(typ)
PCLK = 1.615pF(typ)

Then could I regard that those pin's capacitance is as input capacitance as reference?

Thank you and best regards,
Kazuki Kuramochi

Thomas-san,

I understand that IBIS model is using just 1 sample and it has difference against datasheet's value.
However, you suggested to use IBIS model to estimate impact from input capacitance.
So I'll explain them about they can use IBIS model's capacitance as just reference but it probably have gap against actual value so we cannot guaranty any result from using IBIS model's capacitance.

Thank you and best regards,
Kazuki Kuramochi