SN74CBT16233: About On-state resistance and Cio(OFF) graph data

Hi Tsukui,

Since this part is quite a bit older (originally released  in 1995) we don't have all of the data. From what I can tell by looking at similar parts from that time period is that data in the datasheet captures the typical value and max values at 0V and 2.4V inputs and there is an increase in resistance with an increase in input voltage and current drawn through the device.

On the note of capacitance - higher frequency can lower capacitance  - but the typical is what you can expect from the majority of the signal range. We don't have any direct data for this part - but it is a safe bet at around 100KHz to assume the 4pF because parasitic capacitance tends to dip at higher frequencies - not increase. Considering this part is rated for 200MHz - you are pretty safe to assume 4pF. Some of our newer parts can spec the relation with frequency.

However I do think we do have some parts that have a lower on capacitance and on resistance - at the cost of slightly less channels as this is our only 16 channel 2:1 mux. But I do believe we have a part that is a good upgrade from what you are currently using.

The TMUX1574 is a low capacitance 4 channel 2:1 mux/demux. It has a typical Off capacitance of 3.5pF and a on capacitance of 7.5pF. It also has a lower on Resistance at 5.5V supply. I have included the figures below for reference:

One note for the capacitance graph is that it shows only from 1MHz onward because there is very little variation before 1MHz and assuming typical is a good rule of thumb.

While this device isn't 16 channel:

The QFN and our SOT-23-THN packages for this part are 5mm^2 and 8mm^2 respectfully and 4 of them with decoupling caps will be smaller than the smallest SN74CBT16233 package (TVSOP - 50mm^2). And the TSSOP version of the TMUX1574 (22mm^2) , 4 of them are still smaller than the other two packages for the SN device. The smaller packages also have the benefit of adding less package parasitics which aren't necessarily noted in the datasheet.

Please let me know if the 1574 is a possible solution for your application- and if you have any further questions please let me know!

Best,

Parker Dodson

Hi Parker,

Thank you for your kind support.
I will introduce MUX1574 to the customer.

Could you tell me another thing about the Cio (OFF) specifications of MUX1574 and SN74CBT16233.
Is Cio (OFF) the ”capacitance to GND” or ”capacitance between the I/O pins”?

Regards,
Yusuke