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https://designers-guide.org/forum/YaBB.pl Measurements >> Other Measurements >> Measurement of Voh spec for receiver with CMO https://designers-guide.org/forum/YaBB.pl?num=1162451586 Message started by dandelion on Nov 1st, 2006, 11:13pm |
Title: Measurement of Voh spec for receiver with CMO Post by dandelion on Nov 1st, 2006, 11:13pm Hi, In many receiver(CMOS/TTL level output)product, it gives the spec of the output high voltage(Voh) as below; ......... Voh 3.8V-typ 4.9V-max the test condition above is Ioh=2mA,Vid=+200mv ........... I drafted the testbench for the above as attached diagram. I want to know if the current source in th ediagram is used in the test. Someone told me it is replaced by the resistor. And also, if I want to deisgn a receiver chip, in the design, how can I simulate this spec?Used an ideal current source? Thanks |
Title: Re: Measurement of Voh spec for receiver wit Post by topquark on Dec 7th, 2006, 4:21am Hi, Hope you may have resolved this. Anyway, just trying to see if my understanding's correct: Voh is the min. o/p level that's read as a logic "high" and Ioh is the current flowing into (a specified) o/p load under that condition, usually it's a capacitive load in case of CMOS. As for your testbench, i/p conditions are ok but at the o/p you need to just put a variable o/p cap load & simulate. measure Vout when Iout is 2mA. This will be your Voh. Hope this's the way you did it. Regards, Gautham |
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