PXI Multiplexer - "Minimum Switch Load" (PXIe-2527)

[B_K_AVL]

Hi,

I have a question about Multiplexer parameter like "Minimum Switch Load".

The value of this parameter is "20 mV/1 mA" (PXIe-2527)

Does it mean, that for the correct input switch of the MUX i need on the input at least 20 mV or at least 1 mA? or both, or just voltage, or just amperage?

I am asking because i want to use the MUX for switching inputs in 4-wire resistant measurement method. In the first wire pair there will be Voltage about 3 VDC and current about 0,03 mA, in the second pair there will be current about 100 mA and very low voltage.

[katkam]

Hello @B_K_AVL,

Modules like PXIe 2527 (mechanical switches) require a minimum power to switch, to get solid closure between the contacts of the relay. This means that if the current is low, but at the same time the voltage is high (or the opposite way around), you are fine. 

The problem might be seen when both current and voltage are low. That's why the specification is written this way.

Best regards,

KK

[basketmat]

What about PXI 2501? Is it possible to use it for voltage measurement? 

[katkam]

Hi @Basketmat,

The PXI 2501 is ideal for applications that require high‐speed scanning of low‐voltage signals. The working range for it is +/-10 VDC. You can find this information in a product specification. The topic was also discussed already on one of the forum posts, which you can find here

Regards,

KK

[basketmat]

What would happen if I measure 3.2V voltage with 90kOhm (35uA current) through the mux NI PXI-2503 and NI PXI-2501? 

Which one would be better for this application? Speed of switching is not my concern.