Choosing a CMOS Switch (ADG1434)

Hello,

I need to switch different signals to an ADC. I already choose the AD7195 for my application.

In the application I need to multiplex a differential input of the ADC (channel AIN1 and AIN2).

I want to use a CMOS switch for that.

Another point is that I have an embedded system supplied by around 12V (9V to 20V in fact).

ADG1434 sound good for my application, but can I supply this part with my supply voltage (9V to 20V)?

Or is a regulated 12V mandatory?

In fact it is not plane to use differential +-5V or +- 15V on the board.

  • 0
    •  Analog Employees 
    on Jun 25, 2013 1:01 PM

    Hello Ahygoon,

    A regulated supply for the ADG1434 is not required, but you need to understand that the on resistance of the channel will change with supply voltage. This is presented in the datasheet on page 10, figure 10.

    However, it is not recommended to used the ADG1434 above the specified VDD = 16.5V as it could affect the lifetime and reliability of the part. The recommended part for high voltage use would be the ADG5434.

    You mention a differential signal but only a single voltage supply; please ensure that the signal range remains within the supply rails of the switch.

    Regards,

    Sean

  • Hello,

    My signals come from strain gauges and have a differential voltage output (some mV) around a common mode voltage of 4V.

    Theses signlas may be short-cicuited to Ubat.

    ADG5434 seems to correspond perfectly to my need.

    Thanks