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SE555: Absolute Maximum Ratings.

Kengo.Y
Guru 11495 points

Part Number: SE555

Hi team,

Could you tell me about the Absolute Maximum Ratings of the following pins?

*Absolute MIN voltage.
CONT(5pin), RESET(4pin), THRES(6pin), TRIG(2pin),Vcc(8pin)

*Absolute MIN/MAX voltage.
OUT(3pin),DISCH(7pin)

Sincerely.
Kengo.


  • 0
    TI__Mastermind 31235 points

    Kengo,

    The specified minimum voltage is 5V for the supply. 

    For this condition the specified minimum voltages are:

    Threshold Voltage 2.7V

    Trigger voltage level 1.45V

    Reset Voltage level 300mV

    In Astable mode of operation the discharge pin is connected to resistor RA and RB listed in the product data sheet and discharges the timing capacitor. In Monostable mode of operation the discharge pin is connected to resistor RA shown in Figure 9. Resistor RA will act as a pull up resistor to the supply pin VCC as the timing capacitor charges, This pin and the output should not be forced with a voltage. These two pins should not exceed VCC. 

  • 0 in reply to Chris Featherstone
    Guru 11495 points

    Chris,

    Thank you for your reply.

    Is there a minimum voltage that can be destroyed for these pins?
    I want to know the minimum voltage that should not be applied.

    Sincerely.
    Kengo.

  • 0 in reply to Kengo.Y
    TI__Mastermind 31235 points

    Kengo,

    What mode of operation will you be using? If the reset pin is tied to the supply it will follow the supply pin and there isn't worry of damage unless you exceed the max voltage or force a negative voltage below ground. The other pins should not exceed the supply or go below ground. We do not specify a minimum for these pins but they shouldn't be reversed biased against ground. Will you be applying a voltage to the control pin?

    Just need some more details to understand your use case for better guidance. 

  • 0 in reply to Kengo.Y
    TI__Mastermind 31235 points

    Kengo,

    I reached out to the design team and a good general rule would be to not go below -200mV. This would be the case where you reverse bias protection diodes and gives you enough headroom to avoid damage. 

  • 0 in reply to Chris Featherstone
    Guru 11495 points

    Chiris,

    Thank you for your answer,

    My understanding is below.
    Is it correct?
    *Absolute MIN voltage.
    CONT(5pin), RESET(4pin), THRES(6pin), TRIG(2pin),Vcc(8pin)
     ->Absolute MIN voltage is -200mV.

    *Absolute MIN/MAX voltage.
    OUT(3pin),DISCH(7pin)
     -> How much is Absolute MAX voltage?
         Is it a VCC voltage?
         Absolute MIN voltage is -200mV.
         We care about the voltage applied to these pins.

    Sincerely.
    Kengo.

  • 0 in reply to Kengo.Y
    TI__Mastermind 31235 points

    Kengo,

    Minimum =  -200mV for CONT(5pin), RESET(4pin), THRES(6pin), TRIG(2pin),Vcc(8pin) 

    The absolute max is 

  • 0 in reply to Chris Featherstone
    Guru 11495 points

    Chris,

    Could you tell me about OUT(3pin),DISCH(7pin)?
    Absolute MAX voltage and MIN voltage.

    Sincerely.
    Kengo.

  • +1 in reply to Kengo.Y
    TI__Mastermind 31235 points

    Kengo,

    We do not specify a minimum on any pin, however those pins should also not go below -200mV or exceed VCC.  

  • 0 in reply to Kengo.Y
    TI__Mastermind 31235 points

    Kengo,

    There should be care taken with the discharge pin current if shorted to supply. The discharge pin is a low impedance path to ground and the current through this pin should be limited under a fault. We do not specify a max voltage for this pin but the current should be considered in this situation.