Electro nS
Full Member level 6
i have an arduino in a circuit board
the circuit is power through 12v supply , some times i want to program the arduino while the board is off . The problem is that usb is sending 5v to the arduino , while the rest of the ICs are off .
and according to this post : Will cutting power to a CMOS chip effectively remove it from the circuit?
![Mz6Fu.png Mz6Fu.png](https://www.edaboard.com/data/attachments/55/55749-31decb93d877eabc8ab4c5a0213ed1bf.jpg)
the ICs might be damaged due to signal coming from arduino pins causing power up (due to internal diodes used for esd protection) ,
![3Sc7L.png 3Sc7L.png](https://www.edaboard.com/data/attachments/55/55751-f7026aff280f4f8664307556ad0afac6.jpg)
what is the reliable solution to this problem
the only thing i have in mind is to add relays on all (20 GPIOs) of arduino that will connect these pins to the respective ICs when 12v is applied , but this is very costy and makes board larger and decrese reliability which is the most important factor for me now ! maybe some kind of signal solid state relay array could solve the problem ??
the circuit is power through 12v supply , some times i want to program the arduino while the board is off . The problem is that usb is sending 5v to the arduino , while the rest of the ICs are off .
and according to this post : Will cutting power to a CMOS chip effectively remove it from the circuit?
![Mz6Fu.png Mz6Fu.png](https://www.edaboard.com/data/attachments/55/55749-31decb93d877eabc8ab4c5a0213ed1bf.jpg)
the ICs might be damaged due to signal coming from arduino pins causing power up (due to internal diodes used for esd protection) ,
![3Sc7L.png 3Sc7L.png](https://www.edaboard.com/data/attachments/55/55751-f7026aff280f4f8664307556ad0afac6.jpg)
what is the reliable solution to this problem
the only thing i have in mind is to add relays on all (20 GPIOs) of arduino that will connect these pins to the respective ICs when 12v is applied , but this is very costy and makes board larger and decrese reliability which is the most important factor for me now ! maybe some kind of signal solid state relay array could solve the problem ??
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