CD4066B: Input and Output capacitor

K.Hamamoto

Guru 12155 points

Part Number: CD4066B
Other Parts Discussed in Thread: SN74HC4066

I have a question about this device. Is that possible to add any capacitor to IN or OUT line?

If it is possible, how much is that we can add?

I saw some specification such as input capacitor and output capacitor on the datasheet.

Is this the capacitor of pin(terminal capacity) ? Or is this a capacitor that we can add to input or output?

On the other hands, there are only more than VDD=5V specification. Is that possible to use at VDD=3.3V?

Regards,

Koji Hamamoto

over 7 years ago

0 Clemens Ladisch over 7 years ago

Guru 287370 points

These specified capacitances are the parasitic capacitances of the chip itself.

The data lines can handle analog signals, i.e., there is no upper limit on the capacitor that you can connect to it.

0 K.Hamamoto over 7 years ago in reply to Clemens Ladisch

Guru 12155 points

Hi Clemens,

Thank you for your prompt reply.
I understood about the capacitor.

How about the supply voltage? (Can we use at VCC=3.3V?)
I understand the recommend voltage range is 3~18V. However the specifications on the datasheet are only more than 5V supply.

Regards,
Koji Hamamoto

0 Clemens Ladisch over 7 years ago in reply to K.Hamamoto

Guru 287370 points

The chip will work at 3.3 V, but there is no guarantee how well it will work. In other words, the on-state resistance might be rather high.

0 K.Hamamoto over 7 years ago in reply to Clemens Ladisch

Guru 12155 points

Hi Clemens,

Thank you for your reply.

How much is the Ron at 3.3Vdd in worst case? It might be not guaranteed value. However we need to know the worst case.

Regards,

Koji Hamamoto

0 Clemens Ladisch over 7 years ago in reply to K.Hamamoto

Guru 287370 points

A worst-case value would be a guarantee.

This value is not known for 3.3 V.

0 Adam Torma over 7 years ago in reply to Clemens Ladisch

TI__Mastermind 45485 points

There are other switch options that will offer lower on-state resistance I found using the switch search tool for 4-channel 1:1 SPST devices. What do you think about the SN74HC4066? What are you trying to do with the switch?

Thank you,

Adam

Switches & multiplexers

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CD4066B: Input and Output capacitor