Timeline for TVS on 5V external input
Current License: CC BY-SA 4.0
14 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Aug 3, 2023 at 13:39 | comment | added | Nightshade | Thank you I will try, I will leave the TVS, this is an industrial robot meant for commerce, I need the max protection and reliability. more reliability less liability ;) | |
| Aug 2, 2023 at 19:47 | comment | added | Vincent | If you have adequate shielding (Faraday cage effect), EN61000-4-2 and 61000-4-3 pose no problem, as interference remains outside the enclosure, see my answer : electronics.stackexchange.com/a/675846/274961 and the TVS is not necessary. For oscillation draw a Bode diagram of your filter and see the gains at resonance frequencies. If the gain is too high, lower the Q factor of filter. | |
| Aug 2, 2023 at 11:04 | comment | added | Nightshade | Yes, EN61000-4-3 and EN61000-4-2. How do I make sure that there is no oscillation at the parasitic freq. 5V will come through ferrites and EMI filters on the other side. the cable will be shielded with foil for now, maybe we will move to metal braid with cable boot. | |
| Aug 2, 2023 at 10:51 | comment | added | Vincent | The variation of the TVS diode clamping voltage is important. If you need exactly 5V at the end of the cable, this is a bad solution. It's best to use a shielded cable to avoid electrostatic discharge (ESD). About the filtering, you have two LC filter ; FB1 + the parasitic capacitance in the TVS, and L1+C2 (you can also see it as FB1 followed by a PI filter), make sure that the filter's resonance does not create an oscillation at a particular parasitic frequency. It's not what you want. Do you have to pass IEC 61000 standard ? | |
| Aug 2, 2023 at 5:10 | comment | added | Nightshade | not only the ESD troubles me, I try to eliminate EMI as much as possible. | |
| Aug 1, 2023 at 14:41 | comment | added | Andy aka | You should be able to find a simplistic schematic for the generator and it will show an output resistor that is hundreds of ohms. That resistor and the 15 kV dictate the maximum current into the TVS. But, also adding more capacitance at the place where the 200pF is will also kill off ESD and, probably more so than the TVS. | |
| Aug 1, 2023 at 14:08 | comment | added | Nightshade | EN61000-4-2 is the qualification I try to pass. | |
| Aug 1, 2023 at 12:18 | comment | added | Andy aka | The resistance is dominated by the spark generator circuit output resistance in the ESD specification you are trying to meet. En61000 is a typical spec but there are a few number after the 61000 part that apply to the ESD part. Try finding it and searching for an image of the spark generator circuit. They are available. | |
| Aug 1, 2023 at 11:08 | comment | added | Nightshade | I honestly do not know how to address the answer to the question, I know that ESD voltage is easier to figure, the current will be determined by the resistance of the trace or line it impacts, there are so many variables to it as I see it. Unless I do not see it correctly, and will need your help to determine how to calculate it. | |
| Jul 31, 2023 at 14:46 | comment | added | Andy aka | ESD generators have an output resistance defined in the spec you want to meet. The output resistance and the 15 kV imply a potential current peak that the TVS has to handle. That is why I asked for current and not voltage. | |
| Jul 31, 2023 at 14:16 | comment | added | Nightshade | Not really want any surges :D, but lets say 15kV ESD. | |
| Jul 31, 2023 at 10:28 | comment | added | Andy aka | What surge currents are you expecting? | |
| S Jul 31, 2023 at 7:03 | review | First questions | |||
| Jul 31, 2023 at 7:14 | |||||
| S Jul 31, 2023 at 7:03 | history | asked | Nightshade | CC BY-SA 4.0 |