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Ceramic capacitor leakage current at 50 degC

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treez

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Hello,
We are using a multi-stage RC filter to filter a 100Hz waveform in a sense resistor, R1. The filter is as in the attached schematic. What do you think the leakage current will be in the 470nF capacitors at a 50 degree ambient temperature? We are worried about any inaccuracy in the reading due to leakage current.
The datasheets of these 470nF, 0603, 50V, x7r caps dont allude to the leakage current.
Please also find the LTspice sim of the rc filter
 

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I do not have the data but the ceramics (in this application) are ionic conductors and the conductivity will be appreciable around 300C- but still in the megohm-cm range. Around 50C, the leakage current will be probably less than 1nA/V.

At this range (and temp) the surface leakage may become more significant. How about the board leakage current? Also, there is another parallel path for the current and if the leakage current is much less than ...
 
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Does "Mikro ADC" refer to an unbuffered microcontroller (e.g. PIC) analog input? There will be considerable error due to ADC input current, capacitor leakage can be ignored in this relation.
 
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Does "Mikro ADC" refer to an unbuffered microcontroller (e.g. PIC) analog input? There will be considerable error due to ADC input current, capacitor leakage can be ignored in this relation.
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Yes it does....but sorry, forgot to say, it goes via a non inverting opamp of gain 5.7....so it is buffered, effectively.
 

O.K., with very low sampling rate, the ADC input charge error can be neglected. But you still have some input leakage current.
 
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