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Controlling MAX4564 with digital output voltages outside the supply voltage range

Category: Datasheet/Specs
Product Number: MAX4564

The MAX4564 specifies that it can operate at voltage levels as low as +/-1.8V. But this range is well below VIH and VIL thresholds for CMOS-and-TTL-compatible digital inputs. In cases where digital signals are greater than the supply voltages, (1) can the device be safely operated, and (2) what are the VIL and VIH ranges in those cases?

Use case:

I'd like to power the MAX4564 with +/-2.5V supply and control the switch through the IN pin with a 0-to-3.3V digital signal. The datasheet suggests that this might be possible since the internal diodes will clamp the input voltage to V+ + 0.3V, and I need only limit the current to <20mA. Is that the case?

Any clarification would be most appreciated! Thanks!

  • Hi poofjunior,

    The MAX4564 can operate at those voltages, but its performance is only specified for +/-5V, +5V, and +3V. It is sure to work at +/-2.5V, but we cannot guarantee its performance. There is a logic level vs. supply voltage plot that might help you.

     

    We don't recommend having a higher digital input level than the supply. This can damage the device and other components that're connected to the same power rail. 

    In your use case, you can try to look into MAX20337. This is a beyond-the-rail switch that can handle both positive and negative input signals while in single-supply mode. You can power it with the available 0 to 3.3V digital signal.

    I hope this helps.

    Regards,

    Yoworex

  • Thanks for the reply,  ! Can you clarify if the graph above is specifying Voltage-Input-High (VIH), Voltage-Input-Low (VIL) or something else?

  • Hi proofjunior, 

    The graph should be for VIL. 

    Regards,
    Yoworex