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For a project I would need analog switches or multiplexers. I want to switch a Signal (3-10V, up to 10 kHz) onto different outputs. In the best case it should be possible to go up into the MHz range for EIS. I have 60 outputs and I want to be able to also switch two or more outputs simultanously, so that all the outputs are connected to the signal.

I am not sure about which device to use. I think a low on-resistance is what I am looking for. The thing I dont understand in the data sheets is the voltage range that can be switched. If I understood the data sheets correctly I can switch voltages up to the supply voltage, right?

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    \$\begingroup\$ How quickly does it need to switch? What's the load resistance and is your source able to drive 60 loads in parallel? \$\endgroup\$
    – The Photon
    Jun 12, 2023 at 16:12
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    \$\begingroup\$ What is EIS? \$\endgroup\$ Jun 12, 2023 at 16:36
  • \$\begingroup\$ which table of which datasheet are you reading? \$\endgroup\$
    – jsotola
    Jun 12, 2023 at 16:43
  • \$\begingroup\$ Does the "Signal" ever go negative in voltage? Where do these outputs go? (I mean, what kind of load are they driving?) \$\endgroup\$
    – Troutdog
    Jun 12, 2023 at 17:30
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    \$\begingroup\$ You talk about going up to the MHz range. Is this the signal passing through the switch or the switching rate? If the switching rate, you need low-charge injection switches. \$\endgroup\$
    – qrk
    Jun 12, 2023 at 19:38

2 Answers 2

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I am not sure about which device to use. I think a low on-resistance is what I am looking for.

That matters mostly when you want to do passive switching. That's not a given. You may consider a buffer on each output - whether an op-amp or an emitter follower, depending on your application.

In addition to low on-resistance, capacitance also matters. For a fixed voltage range, the lower the on-resistance, the higher the capacitance, since the channel in the pass gates have to be wider.

I have 60 outputs and I want to be able to also switch two or more outputs simultaneously, so that all the outputs are connected to the signal.

Simultaneity is not usually a problem.

I want to switch a Signal (3-10V, up to 10 kHz) onto different outputs

Given the lower prices and high performance per price of crossbar switches for lower voltages, what you may have to do is to attenuate the signal at the input, feed it to a crossbar switch IC, then add a gain stage on each output.

The thing I don't understand in the data sheets is the voltage range that can be switched. If I understood the data sheets correctly I can switch voltages up to the supply voltage, right?

Usually, but really the voltage range is specified. Usually it's specified with relation to the supply voltage, but that's not always the case. The datasheet always specifies it. If you have a problem understanding a particular datasheet, edit your question with a link to a particular datasheet you have a problem with.

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I believe the main source of confusion is this: "a low on-resistance is what I am looking for".

And that comes from the lack of requirements. You did not specify the input impedance of your targets, nor the allowances for signal distortion and slew rates, nor the driving capabilities of your signal source. Depending on these, high RDSon might be the least of your concerns.

For example, if your inputs have 50k impedance at target frequency, what difference does 20Ohm switch resistance make? Or if your source can only drive a few mA, then combined capacitance of 60 inputs may look like a short circuit to it.

Without specific requirements I can only suggest two generic approaches.

If your inputs have high impedance and your signal source is capable of driving them all, then you may be able to use analog switches. Something like 64-channel MP4865A or a daisy chain of switches with less channels. These, by the way, are quite uncommon in that the switching voltage does not depend on supply.

Otherwise you'd need a bunch of buffers with enable input and shift register chip(s). Something like a combination of 20x MAX4019 and one HV507. With buffers the output range definitely depends on a supply, however it should be easier to find buffer with suitable voltage than a switch.

Note that the ICs mentioned above are not actual component suggestions, they are only there to illustrate possible implementation configurations.

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