Hello,
A problem I have is interpreting what the spec sheet is really saying... please consider the following!!!!
Referring to the TLC7226 part and its spec sheet at:
http://www.ti.com/lit/ds/symlink/tlc7226.pdf
If you go to p.4 of the data sheet and look for:
ri(ref) Reference input resistance 2 kΩ min and 4 kΩ typical.
Questions:
1) Does this mean that pin#4 of the TLC7226 part has a typical input resistance from 2kilo ohms to 4 kilo ohms?
2) Please refer to the attachment below where I tried to calculate the actual input resistance at pin #4. As a test, I have created a voltage divider to provide 2.2V as my reference voltage. I have measured the currents in the circuit. If I measure 2.2V at point "A", according to ohms law why is it that the calculation of the internal resistance comes out to 22K when the spec sheet says from 2 to 4 k???
help!
thanks
r
Attached Thumbnails
A problem I have is interpreting what the spec sheet is really saying... please consider the following!!!!
Referring to the TLC7226 part and its spec sheet at:
http://www.ti.com/lit/ds/symlink/tlc7226.pdf
If you go to p.4 of the data sheet and look for:
ri(ref) Reference input resistance 2 kΩ min and 4 kΩ typical.
Questions:
1) Does this mean that pin#4 of the TLC7226 part has a typical input resistance from 2kilo ohms to 4 kilo ohms?
2) Please refer to the attachment below where I tried to calculate the actual input resistance at pin #4. As a test, I have created a voltage divider to provide 2.2V as my reference voltage. I have measured the currents in the circuit. If I measure 2.2V at point "A", according to ohms law why is it that the calculation of the internal resistance comes out to 22K when the spec sheet says from 2 to 4 k???
help!
thanks
r
Attached Thumbnails
Attachments
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