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Determining Output Offset Voltage of Op-AMP?

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blastronics

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output offset voltage opamp

Im designing a DAC and I use an OP-AMP as an output buffer, i have made it with a 2mV resolution. I wory about the output offset voltage of the OP-AMP for it will definitely affect its accuracy. I cant found it on the Data sheet of the CHIP.(LM8272).

How can i know the output offeset voltage of this chip.

Is it indirectly represented on the data sheet?

if not how can i know this?

thanks.

βlastronics
:D
 

**broken link removed**
the first characteristic in the electrical characteristics table says Vos (Input offset voltage) with the values

The output offset voltage is the input offset voltage multiplied by gain of your opamp circuit configuration

If gain is unity (voltage follower configuration) output offset voltage is same as input offset voltage
 

thank for the help.

my design was an Vout max of 8.192volts.

i have a voltage gain (Av) of 2, with an offset of 1.4v for the entire voltage, i gues this is acceptable enough.

is it always understood that the output offset voltage is equivalent to input offset multiply by the gain? Or this is just a good approximation in cases where output offset is not specified?

thanks.

:D:D:D

β
 

Output offset voltage is the voltage which will appear at output when there is no input (that is inputs are 0V)
Input offset voltage is the voltage required to make the output 0V

From the above two definitions you can see both refers to same characteristics but defined differently

Normally in all datasheets only input offset voltage is specified
Read this book on opamp it has very nice explaination about opamps
 

The offset cannot affect the acuracy of your DA. The linearity of the chip can.
 

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