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CAPSENSE™ & MagSense

befic_2639911
New Contributor II

Hi,

    From <<Cypress’ CapSense Sigma-Delta Algorithm>>,we know CY8C21x34 has a special CSD structure with a bleed resistor. and it works very interesting

as the document says.

     Now according to AN64846, PSOC 4S series has a fouth-generation capsense. it is called CSD_V2,isn't it?  there is no bleed resistor. i don't know how it works . who can tell something about it?

    And is capsense in CY8C21x34 the third generation capsense, with the CSD_V1 structure?

 

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Vison_Zhang
Moderator
Moderator

CapSense in CY8C21X34 is the 1st generation CSD structure (with a bleed resistor) , this structure is great invention, it provides good noise rejection performance, high SNR, and high stability.  The disadvantage of this structure is you have to change the Rbleed value to tune the sensor rawdata level, but when sensor's parasitic capacitance(CP) is very different, the Rbleed resister is hard to choose. So in next generation structure, Rbleed is replaced by IDACs, so we can tune each sensor independently.

You can read PSoC4 CapSense Design Guide to know how the new structure works.

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Vison_Zhang
Moderator
Moderator

CapSense in CY8C21X34 is the 1st generation CSD structure (with a bleed resistor) , this structure is great invention, it provides good noise rejection performance, high SNR, and high stability.  The disadvantage of this structure is you have to change the Rbleed value to tune the sensor rawdata level, but when sensor's parasitic capacitance(CP) is very different, the Rbleed resister is hard to choose. So in next generation structure, Rbleed is replaced by IDACs, so we can tune each sensor independently.

You can read PSoC4 CapSense Design Guide to know how the new structure works.

View solution in original post

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