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Schematic 18f4550 interface SD card

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kideltn

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Hi every one !
I am researching interface between 4550 and sdcard
I have a schematic of 4550 and sdcard but i have several problem
My schematic:
untitled-10.jpg

My query,sd operate with voltage 3,3 V
I see above shematic the interface pin sdcard and pic directly connect(PIC 4550 is 5V)
Please help me above shematic is true or false !
If false please give me a solution !
I am beginer in hardware and perhaps my question rather stupid.
But i hope i will receive many helping !
Thanks every one alot !
 

mindthomas

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You are right about the F versions runs on 5V, and therefor this schematic is false.
If you connect the SD card to 5V you would destroy it, you have to use some resistors to form a restor dividing grid - please take a look at this link: https://en.wikipedia.org/wiki/Voltage_divider

Then for R1 use a 1.8K resistor, and for R2 use a 3.3K.
This would make the output around 3.3V - 3.24V to be presise :)
 

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