Series Resistor between PSoC and Bluetooth Module

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Anonymous
Not applicable

My current design uses a PSoC3 and Microchip RN42 Bluetooth module. I haven't been using a series resistor on the UART lines between the two devices, but I see a lot of design that do use series resistors between digital communication lines. 

   

 

   

Should I include series resistors between PSoC and BT module? Looks like the RN42 can handle a max of 5mA per pin.

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ETRO_SSN583
Level 9
Level 9
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Series R's are used primarilily in high speed digital routes

   

to kill the over/undershoot generated by L in route, basically

   

make L look incredibly lossy. If using your scope you see under

   

and overshoot that exceeds specs then consider them.

   

 

   

Usually they are picked for a specific layout, trial an error, but

   

20 - 100 ohms typical values.

   

 

   

Regards, Dana.

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