TINA/Spice/LM193: Input offset voltage

Midhun M

Part Number: LM193
Other Parts Discussed in Thread: TINA-TI,

Tool/software: TINA-TI or Spice Models

Hi,

In the spice model provided for LM193, what is the input offset voltage value?

On simulation with both inputs shorted to ground and applying 3.3V supply to the model, the simulation results shows 18mV of input offset voltage which is not matching with the datasheet provided value.

In datasheet 9mV of offset voltage is mentioned over temperature.

Thanks

Midhun

over 6 years ago

0 John Miller - Sensing over 6 years ago

TI__Mastermind 33250 points

Midhun,

I ran a DC transfer curve of the LM193 model. It looks like the offset voltage is about 40uV at VCC = 10V.
For VCC = 3.3V, the input offset appears to be about 47uV.

The transfer curve for VCC=10V appears below. The Pspice test circuit is in the second plot below.

Please let me know if you have anymore questions.

Regards,
John

0 Midhun M over 6 years ago in reply to John Miller - Sensing

Prodigy 230 points

Thank you John..
Can you please tell me how is the offset voltage measured.
The value 47uV is calculated from the graph?

Regards,
Midhun

0 John Miller - Sensing over 6 years ago in reply to Midhun M

TI__Mastermind 33250 points

Midhun,
I mis-spoke in my last message. The VOS estimated from the graph is about 39uV, not 47uV. Apologies for that.
The 39uV comes from the input voltage that causes the output to be at the mid-point (= 5V). If the device was ideal - with no offset - the output mid-point would happen for an input of 0V.
Regards,
John

0 Midhun M over 6 years ago in reply to John Miller - Sensing

Prodigy 230 points

Thanks John.

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TINA/Spice/LM193: Input offset voltage