Hi @ScottWang, for signals I don't think it need high current where CD4053 should able to provide. Can there be any other case for the Voltage Drop?

Please show all your circuits.

 

Thank you.

You mean that this application needs Ghz bjt?

Thats my conclusion as well, near Ghz Ft's


Regards, Dana.

 

The 2N2369 and 2N5771 have saturation storage times of 13ns and 20ns max. respectively.
Below is the Ltspice simulation comparing the switching time of a 2N2369 to a 2N3904 showing the long saturation delay of the 2N3904.
But that is probably still be too slow for this application.

View attachment 182820

The 2369 may also not be fast enough if the SPI is being done at 10 Mbs, but now
that we know its a camera interface I would seriously doubt its 10 Mbs capable.


Regards, Dana.

 

2N390x should do up to 300MHz or so ?

+ random alternative

 

2N390x should do up to 300MHz or so ?

Only if it's not saturated during the switching.

 

Hi @BobTPH. I fully agree with you that the 3V HIGH and 2V LOW is a rare case.

Actually my project is controlling Canon DSLR Flash (E-TTL) from MCU. Here I measured by DSO the Signals between DSLR and Flash Hot-Shoe port and gets the voltage Levels are below:

CLK: LOW 2V, HIGH 4.5V
DATA: LOW 2V, HIGH 3V

For this I need the Voltage Levels conversion.

Hi @ScottWang, for signals I don't think it need high current where CD4053 should able to provide. Can there be any other case for the Voltage Drop?

Regards.

Okay, so these are the measured voltages of a device that is communicating with the one you want to.

That does not mean that they need to be copied exactly. You need to know the specification of the device you are talking to. This will give an acceptable range of voltages, making your task far easier. For example, I find it hard to believe, based on what you have said, that the camera would not interpret 0V, or any voltage below 2V as a valid low. I think everyone here is trying to solve a non-existent problem based on a misunderstanding. I hate it when that happens.

Do you have such a specification? If not, have you looked for one?

Bob