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SN74LVC1T45-Q1: about Min VOH and Max VOL at VCCA = VCCB = Min 5.1V/Max 5.5V

Paul Kim
Intellectual 1430 points
Part Number: SN74LVC1T45-Q1

Hi team

can I know Min VOH and Max VOL at the below conditions ?

[1] at VCCA = VCCB = Min 5.1V/Max 5.5V and DIR = GND, 

     what is Min VOH on Port A(No 3 pin) at below IOH = - 100uA ?

     what is Min VOH on Port A(No 3 pin) at below IOH = - 200uA ?

     what is Min VOH on Port A(No 3 pin) at below IOH = - 300uA ?

[2] at VCCA = VCCB = Min 5.1V/Max 5.5V and DIR = GND, 

     what is Max VOL on Port A(No 3 pin) at below IOH = 100uA ?

     what is Min VOH on Port A(No 3 pin) at below IOH = 200uA ?

     what is Min VOH on Port A(No 3 pin) at below IOH = 300uA ?

  • 0
    TI__Mastermind 44775 points

    Hi Paul,

    Please refer to question 6 from the link below. This will help you calculate the VOH/VOL spec for any VCC/IOL/IOH.

  • 0 in reply to Dylan Hubbard
    TI__Intellectual 1430 points

    Hi Dylan

    I would like to use IOH = IOL = 4mA specification on D/S for VOH & VOL calculation of worst case +- 1mA.

    the below are correct ?

    for the estimated VOH,

    (VCC - VOH) / IOH = (1.65V - 1.2V) / 4mA = 112.5 ohm.

    at 1mA case,

    1mA x 112.5 ohm = 0.1125V

    Hense. VOH will be above 4.9875V(= 5.1V - 0.1125V) at VCC = 5.1V ~ 5.5V range.

    for the estimated VOL,

             VOL / IOL = 0.45V / 4mA = 112.5 ohm

    at 1mA case,

    1mA x 112.5 ohm = 0.1125V

    Hense. VOL will be below 0.1125V at VCC = 5.1V ~ 5.5V range.

  • 0 in reply to Paul Kim
    TI__Mastermind 44775 points
    Hi Paul,

    You did everything correct except for one thing: you should use the test condition that has the closest supply voltage instead of closest IOL/IOH. For example, you want to use the data for the 4.5V VCCA/VCCB. This is due to the decreasing output resistance as supply voltage increases. This will give you a more accurate value when doing the calculations.