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TLV7011: Input Protection Diode

Zeki Sisman
Intellectual 320 points
Part Number: TLV7011

Hi All,

I am planning on using this part in a logic level shifting application. I detect the input voltage via a high impedance resistor divider. Due to the nature of my input levels, there is a chance that I can exceed VDD and VEE levels of the component.

Datasheet says: "Input terminals are diode-clamped to VEE. Input signals that can swing 0.3V below VEE must be current-limited to 10mA or less." 

Since my sense path is high impedance, I don't exceed the current limit when I go below Vee and turn the internal diode ON. However datasheet does not mention a protection diode from input to VDD. In spice simulations I see that the input is clamped to VDD when the input signal gets too high though, so I suspect there is a protection diode on that pin as well. 

Do you have any information on this? I think since my path limits the current to less than 1mA I should not need any additional protection even when the input tries to exceed VDD. Do you agree?

Kind regards,

Zack.S.

  • 0
    TI__Mastermind 23425 points

    Zack

    Sorry for the confusion in the model but it sounds like you are on the right track.  Your resistor divider will current limit and protect the ESD diode that clamps the input to a diode below VEE.  However, the protection on the high side is not a simple diode.  Your resistor divider will help but it is also important that you do not exceed the abs max voltage of 6V.  This value is independent of the supply voltage applied to VCC.  Can you adjust your resistor divider such that the max input voltage does not exceed 6V?  This would be the best scenario.  If not, you will need to have an external clamp that will limit the input voltage on the comparator side of the resistor divider.

    Chuck

  • 0 in reply to Chuck Sins
    Intellectual 320 points

    Chuck,

    Thank you for your explanation! Now it is clearer to me. I will check the impact of changing the divider ratio as you suggested, worst case I will put a clamp to limit the pin below 6V.

    Regards,

    Zack