bzr2915
Newbie level 6
Help! About PMOS Diode connection (current direction)
![QQ截图20121229112756.png QQ截图20121229112756.png](https://www.edaboard.com/data/attachments/27/27259-de656289180fa8eb787af9d7e2d113fd.jpg)
The figure above is a PMOS, when VL is higher than VR, there will be a current from VL to VR. It means that the diode turns on when it is forward-biased. On the other hand, when VR is higher than VL, the voltage of drain is higher than that of the substrate, so the drain-body junction starts to conduct.
Then my question is what is the diode direction? Base on the above statement it should be a bidirectional diode, right?
![QQ截图20121229113748.png QQ截图20121229113748.png](https://www.edaboard.com/data/attachments/27/27261-07072dffd3b5d9e844aec138e9247b29.jpg)
The figure above is voltage doubler and if it's a bidirectional thing how does it work?
PS: I notice if I change the voltage doubler to NMOS the output will become negetive instead of POMS positive. Why?
Thank you for your rely!
![QQ截图20121229112756.png QQ截图20121229112756.png](https://www.edaboard.com/data/attachments/27/27259-de656289180fa8eb787af9d7e2d113fd.jpg)
The figure above is a PMOS, when VL is higher than VR, there will be a current from VL to VR. It means that the diode turns on when it is forward-biased. On the other hand, when VR is higher than VL, the voltage of drain is higher than that of the substrate, so the drain-body junction starts to conduct.
Then my question is what is the diode direction? Base on the above statement it should be a bidirectional diode, right?
![QQ截图20121229113748.png QQ截图20121229113748.png](https://www.edaboard.com/data/attachments/27/27261-07072dffd3b5d9e844aec138e9247b29.jpg)
The figure above is voltage doubler and if it's a bidirectional thing how does it work?
PS: I notice if I change the voltage doubler to NMOS the output will become negetive instead of POMS positive. Why?
Thank you for your rely!
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