I'm designing a unity gain buffer (IC MCP6002) and in the datasheet, it says that a small series resistor is required at the output, if the load is capacitive and is >100pF. The input of the buffer is a varying ADC value from one microcontroller and the output of the buffer is given to the ADC input pin of a second microcontroller.

Is the microcontroller at the output considered a capacitive load in any way?

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    \$\begingroup\$ The datasheet for the "second microcontroller" will specify the input capacitance. \$\endgroup\$ – Transistor May 2 at 22:37
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    \$\begingroup\$ And if it doesn't, figure it'll be around 10pF. It should be in or close to the "electrical characteristics" section. I actually looked up a data sheet for an ATTINY, and at first read couldn't find a capacitance spec for the input pins. \$\endgroup\$ – TimWescott May 2 at 22:45
  • \$\begingroup\$ I'm using the PIC24FJ64GB004 as the output microcontroller. On page 267 of its datasheet, Figure 22-2, mentions 'input capacitance' and the 'sample/hold capacitance'. So the total capacitance comes up to about 15.4pF. Have I missed out on any other capacitance? \$\endgroup\$ – J2018 May 2 at 22:56
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    \$\begingroup\$ only track to ground capacitance which is tiny. so yer ok \$\endgroup\$ – Sunnyskyguy EE75 May 2 at 23:32
  • \$\begingroup\$ Thank You everyone for your help. \$\endgroup\$ – J2018 May 3 at 13:31

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