kali1503
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i'm a newbie and i'm designing LDO with Vin=3.5 V and Vout=3.1 V. I have a problem that when i simulate with Vin increase from 0V to 3.5V.
If Vin increase from 0 to 3.5V in 5ms, vout is stably about 3.1 V.It's ok.(pic1).
But if Vin increase from 0 to 3.5V in shorter range of time, about 500us, vout is not stabe,it oscillate.(pic 2)
I asked some colleagues and they said that the reason is gain bandwidth of error amplifier is not high enough. It's correct or not ?
My professor required that this LDO must work well when the input voltage increase from 0 to 3.5 in 1us.
Can you give me some advices.
Thanks a lot
![pic1.jpg pic1.jpg](https://www.edaboard.com/data/attachments/28/28937-896b14c8c84ffce39beeb262f709cc37.jpg)
![pic2.jpg pic2.jpg](https://www.edaboard.com/data/attachments/28/28938-10a19fe18fac3e2015ea6b07c8903f1f.jpg)
If Vin increase from 0 to 3.5V in 5ms, vout is stably about 3.1 V.It's ok.(pic1).
But if Vin increase from 0 to 3.5V in shorter range of time, about 500us, vout is not stabe,it oscillate.(pic 2)
I asked some colleagues and they said that the reason is gain bandwidth of error amplifier is not high enough. It's correct or not ?
My professor required that this LDO must work well when the input voltage increase from 0 to 3.5 in 1us.
Can you give me some advices.
Thanks a lot
![pic1.jpg pic1.jpg](https://www.edaboard.com/data/attachments/28/28937-896b14c8c84ffce39beeb262f709cc37.jpg)
![pic2.jpg pic2.jpg](https://www.edaboard.com/data/attachments/28/28938-10a19fe18fac3e2015ea6b07c8903f1f.jpg)