Looking for pin capacitance for Digital Inputs pins. Info not on datasheet.
Brian,
I connected the device to a mosfet pulling low on the Reset pin and then releasing allowing a pull up resistor (9060 ohms) to pull the signal up to Vcc (5V). I measured the 30% time value and 70% time value and looked at the difference which I call the rise time.
Capacitance = t_rise/(0.8473*pullupresistor)
Measurement of just my set up below (no device connected)|| capacitance comes out to 186.7pF
||Connected to the test set up||
(with RE' pin connected)|| capacitance comes out to 191.5pF
(with DE pin connected)|| capacitance comes out to 196.6 pF
(with D pin connected)|| capacitance comes out to 192.3pF
The difference between the test set up and the measured pins gives us the capacitance values
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RE' pin = ~4.8pF
DE pin =~9.9pF
D pin =~5.6pF
-Bobby
