Timeline for Bidirectional protection or isolation for generic digital communications
Current License: CC BY-SA 4.0
12 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Feb 26, 2020 at 14:07 | vote | accept | Daniel | ||
| Feb 19, 2020 at 4:19 | comment | added | DKNguyen | If you put the R in series with the D it will limit current through the diode, but it will not allow the diode to clamp the voltage at the pin. What stops the pin from seeing the full overvoltage when the resistor is in series with the diode? It's a straight connection from the overvoltage to the pin. | |
| Feb 19, 2020 at 4:17 | comment | added | DKNguyen | @Daniel Sounds like you need to review some basics about how voltage drops work. The resistor needs to be between the diode and the overvoltage to stop the diode from frying. The diode needs to be directly connected to the pin to clamp the voltage at the pin. That inherently means the resistor in series with the pin. Sure, a resistor in series can disturb the signals but its your job to find out how much resistance can be tolerated. | |
| Feb 19, 2020 at 4:12 | comment | added | Daniel | But why put resistor in series with line communication? I'm not sure if a resistor in the line communications can disturb the signals. Why resistor can not stay in TVS branch? | |
| Feb 19, 2020 at 4:07 | comment | added | DKNguyen | @Daniel If it fails, it should fail short, as most semiconductors do. | |
| Feb 19, 2020 at 4:07 | comment | added | Daniel | O will study the possibility to use it in the circuit. It is important to know what happens when they fail, it become a open circuit or become a short. | |
| Feb 19, 2020 at 4:05 | history | edited | DKNguyen | CC BY-SA 4.0 |
added 270 characters in body
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| Feb 19, 2020 at 4:01 | comment | added | DKNguyen | @Daniel Resistors are in series with the pin.The TVS is between the pin and GND. Just like a zener diode regulator. | |
| Feb 19, 2020 at 4:00 | comment | added | Daniel | Yes, @DKNguyen. I meant about the harzard time. But, the resistors will be in series with the TVS right? The resistor can improve the time that TVS can drain the current, that was what you meant? | |
| Feb 19, 2020 at 3:52 | comment | added | DKNguyen | @Daniel "it has action for a few milliseconds" Huh? You do realize that TVS diodes are extremely fast, right? Unless you mean the hazard time is too long, which is why the resistors are there with the TVS. You also never actually said why you think resistors aren't good in this situtation. It sounds more like you just have no idea what the communication protocols present can handle. As it stands you are looking for inexpensive, broad protection, that won't interfere at all with the signals. If such a thing existed, it would be in use everywhere. | |
| Feb 19, 2020 at 3:50 | comment | added | Daniel | I don't think resistors in communication lines are a good thing mainly in this situation. About TVS, it is interesting, but it has action for a few milliseconds, so, it will not prevent damage. | |
| Feb 18, 2020 at 17:16 | history | answered | DKNguyen | CC BY-SA 4.0 |