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In OPA2316SIRUGR, how is the output status when SHDN pin is deasserted(Low to High)?
Does it depend on input status or start from V- voltage level?
Nakagawa,
The output become active (leaves high impedance state) and will respond to input status. [However, the output may go lower or higher momentarily before fully following the input status]
Hi Ron
Thank you for confirming.
But I had another experience, the output started from V- level.
Would you please confirm it again?
I used OPA2316 with below conditoin.
V+ : +3.3V, V- : 0V, +In : 1.59V, -In : 1.44V
After SHDN pin was deasserted (from 0V to +3.3V), output was high impeadance state until 6us later.
And then output goes to 0V, from 6us to 8us.
After that, output respond to input state, that means output go to V+ level.
BR
Nakagawa
Nakagawa,
I found some samples.
For most supply voltages, the output does visit 0V before settling on the correct output value.
Setup is unity gain. VIN = 1.5V, load is 100k to 0.75V, top trace is enable and bottom trace is output
With 5V supply, there was output low time on enable and a positive rise at disable
With 3.3V supply, there was output low time on enable and a positive rise at disable
With 1.8V supply, there was no output low time
Due to time for each section to turn on or off not being perfectly balanced, the output can go positive or negative momentarily before settle on the correct output voltage.
Hi Ron
Understood with thanks.
For my application, the low time cause troubles.
Could you suggest solution for it ?
Or can't I avoid this phenomina ?
BR
Nakagawa
Hi Ron
Even if a sample enables cleanly there is no guarantee that every unit will do the same thing and do it every time. Therefore it is best to ignore output until the device has fully recovered from shutdown mode.
Did you mention that TI can't distinguish which parts was designed with no VOL and VOH pulse?
I think your comment meaans you don't have enough information about it now.
If you have enough time, you can proove that the device can operate with no VOL and VOH pulse completely or not.
Does my understanding correct?
Anyway, I appriciate your support in this time.
After you get 4 rest samples and evaluate them, please let me know results.
BR
Nakagawa
Hi Ron
Thank you for your comment.
I understood waht you mentioned.
But I can't ignore the low-time in my application.
I really want to search suitable one.
Please let me know the result of devices whoch you are ordering now.
BR
Nakagawa
Hi Kai
Thank you for comment.
In this time, I learned that It is usual OpAmp characterisitics that they doesn't gurantee the specification in shutdown.
Your suggestion helps me to solve my issue.
BR
Nakagawa