Part Number: SN74LV74A
Hi,
My customer wants to calculate VOH under conditions not listed in the datasheet. and customer believes that once the impedance is known, it can be calculated.
My impedance calculation is ”Zo =(V㏄ – Voh min)/Ioh”.
However, the impedance differs depending on the power supply voltage & Ioh.
at Vcc = 2.3V: (2.3 – 2)/2 = 0.15kohm
at Vcc=3V: (3 – 2.48)/6=0.087kohm
at Vcc=4.5: (4.5 – 3.8)/12=0.058kohm
So, Voh = Vcc - Zo * Ioh
When the conditions for calculating this are at 3.3V, Ioh=6mA,
Applying Zo = 0.087k ohm as an approximation gives
Voh at 3.3V = 3.3 - 0.087 *6=2.778V
Is this correct?
Also, in cases like Vcc=5V and Ioh=6mA, the impedance is
Which value should be applied?
Best regards,
Hiroshi
