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sinara-hw / Stabilizer

2-channel microcontroller servo with EEM and Ethernet based on STM32 CPU
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DI0/1 input protection #90

Closed jordens closed 2 years ago

jordens commented 3 years ago

The buffer doesn't like high or low input voltages and will clamp. Can we add 1k at the buffer input after the AC termination to limit the current?

image

gkasprow commented 3 years ago

sure, if connect it to output specified as 5V TTL at 50R load it may even cause latch-up effect. We should add a TVS and series resistor.

gkasprow commented 2 years ago

The Schottky diode has a much lower Vf, so it should prevent latchup. Since we are changing buffers to bi-dir, 1k would be too much at the output.