AM26LV31E-EP: Driver output impedance

Hi Pierre,

Output impedance isn't directly spec'd - you can approximate typical and minimum by looking at the VOH and VOL, using a 3.3V source and current values - that means with a VOH of 3V typically with 20mA of current from a 3.3V source is about 15 Ohms - but this can change over operation as the VOH can be lower than 3V.

Variations due to environmental conditions like temperature are reflected in the maximum and minimum specifications in the datasheet. This device is not radiation hardened and shouldn't be used in high radiation environments as there is no data on how this part will react. 

Once device has gone out of spec - possibly due to age - it would be considered a failed device - we don't have spec data on that but we do have MBTF and FIT data which is the closest data we'd have to any failure of devices results attached below - but you can also use the link: https://www.ti.com/quality/docs/estimator.tsp#resultstable 

results (5).xlsx

Best,

Parker Dodson

Hi Parker,

Thank you very much for your return and trying to answer my request out of the specified characteristics. I understand your reasoning but are you sure it's correct: VOH typ is equal to 2.3V and with 1V drop out from the 3.3V supply with a 12mA load, it would lead to a typical output impedance of 83 ohms, which is huge!

I try to evaluate this parameter which has an important influence in the case of a series termination, knowing that some high grade drivers on the market claim an impedance of 5 to 10 ohms over the entire range of use and that it is said, the commercial CMOS part types have output impedances varying from 5 up to >100Ω over the output swing.

Thank you again for your help,

Best regards

Pierre

Hi Clemens,

Thank you very much for the curve. It seems not  to be consistent with the datasheet which is 2.3V for 12mA, unless the curve is closed to the minimum characteristics (1.85V for 12mA). It seems the output cannot be higher than 2.15V with no current.

Then, the output impedance could be calculated on the linear part: (2.15 - 1.4)/60mA = 12.5ohms

What do you think? Am I right ?

Would it be possible to get the numerical data of the curve?

Thank you again for your help

Best Regards

Pierre