3 ms·
DFT = Design For Test https://en.m.wikipedia.org/wiki/Design_for_testing https://en.m.wikipedia.org/wiki/Design_for_testing They have a resistor to ground in p
by egsmi 6y ago
DFT = Design For Test
https://en.m.wikipedia.org/wiki/Design_for_testing https://en.m.wikipedia.org/wiki/Design_for_testing
They have a resistor to ground in parallel with the buffer? I get the diode but I can only assume the resistor is a weak pull to prevent charge building up at the pin. But it seems the diode would mostly do that job, to the point of preventing damage anyway. I guess they weren’t concerned with leakage power then.
Protection resistors in series with the buffer are fairly common these days. Especially on GPIO type pins.
- kens 6y agoThe resistor is on series. I.e pin - resistor - diode to ground and circuitry. The resistor is just some silicon, probably around 30 ohms.
- egsmi 6y agoThat makes sense. That’s the current limiting resistor. It protects the protection. See page 12 of this deck. http://www.eng.biu.ac.il/temanad/files/2017/02/Lecture-9-IO.pdf http://www.eng.biu.ac.il/temanad/files/2017/02/Lecture-9-IO....