74VHC4052AFT mux type - make before break / break before make

[Ribster]

Hi all

I'm designing a resistance measurement thing.
It will have a constant current sink inside. This will be achieved with the MAX8515.
To select my ranges i would love to incorporate a 4:1 mux.
I've selected the 4052. But for the life of me, i cannot find the type of the mux.
So the switching behaviour. Brake before make or make before break.
From page 12 of the toshiba datasheet, AC Test Circuit i would assume a break before make behaviour, but i don't have 100% assurance about this.

Anyone has some experience with the 4052 ?

Kind regards

[Kleinstein]

I have not look much at 4052, but on the same serie 4053: there is a relatively short break before make time - not much (e.g. 10-50 ns), but usually enough to ensure there is no cross conduction. The different series (HC, AHC, VHC, LV) can be a bit different. Resistance measurement should not really case much about 10 ns range timing. For the 10 ns time scale there is also the charge injection that becomes relevant - so there is additional current from the gates, not just between the inputs.

[edavid]

As you have noticed, this behavior is not defined in the datasheet.  If you need break before make, you should add blanking time.  If you need make before break, use a different part.

What is it about your circuit that requires you to know this?

[Ribster]

Thanks all for your input.
It is the right part price wise and spec wise.
Im using it to select a resistor. My fear is that i switch and the MAX8515 does some crazy things.
So i've placed a resistor in parallel over this switching. That way the circuit does not see an open for 10ns.
I hope this one will be sufficient!