I am using a IR2101 gate driver circuitry to switch the high side IGBT ON (I do not want it to be periodic). Hence I found out that since I am not frequently switching the IGBT, the bootstrap circuitry doesnt not work since the capacitor cannot charge up.
I therefore found out 2 ways I can achieve non-periodic switching of high side IGBT:
1) Use an isolated/floating power supply
2) I can add a charge pump circuitry to my current gater driver circuitry.
However, I do not understand how should I incorporate/ use the above two methods with my gate driver to switch the high side IGBT. Please help me with some circuit configurations for the above two methods, as that would make things very clear for me, rather than explaining the circuitry connections with words.
My circuit application looks as follows:
The problem, however, is when I apply 3.3V to the gate driver, I measure the voltage VB-Vs I get 12 V (correct since my 4.4 μF tantalum cap charges). If I measure VB-HO I get 12 V (I don't know why this happens), and the voltage at HO-Vs (emitter of Q1) is 0 V.
Here I dont undertand couple of things:
1) Why is the voltage at HO-Vs (emitter of Q1) is 0 V when I give 3.3V to HIN?
2) I expect the capacitor to discharge when I supply 3.3V to HIN, however when I measure the voltage across the capacitor (VB-VS) it stays 12V, and this means that the capacitor doesnt discharge, hence the 3.3V signal isnt turning the IGBT ON (even for a short while, which would discharge the capacitor fully, and therefore even if I continue to apply 3.3V at HIN, after a short while I should measure 0V across the capacitor, which I do not).
- I would like to stick with N channel and not P channel (because I have them ready for implementation).
- Would really like to use isolated DC-DC converter power supply (either use it individually to connect it to the gate and emitter of the IGBT and switch the converter ON and OFF) or integrate it with IR2101 somehow. (Need help in this application)
- Lastly if nothing works try using charge pump circuitry and integrate that circuitry with the current gate driver I have. (Need help in this application)
Your response will be extremely helpful to me.
I therefore found out 2 ways I can achieve non-periodic switching of high side IGBT:
1) Use an isolated/floating power supply
2) I can add a charge pump circuitry to my current gater driver circuitry.
However, I do not understand how should I incorporate/ use the above two methods with my gate driver to switch the high side IGBT. Please help me with some circuit configurations for the above two methods, as that would make things very clear for me, rather than explaining the circuitry connections with words.
My circuit application looks as follows:
The problem, however, is when I apply 3.3V to the gate driver, I measure the voltage VB-Vs I get 12 V (correct since my 4.4 μF tantalum cap charges). If I measure VB-HO I get 12 V (I don't know why this happens), and the voltage at HO-Vs (emitter of Q1) is 0 V.
Here I dont undertand couple of things:
1) Why is the voltage at HO-Vs (emitter of Q1) is 0 V when I give 3.3V to HIN?
2) I expect the capacitor to discharge when I supply 3.3V to HIN, however when I measure the voltage across the capacitor (VB-VS) it stays 12V, and this means that the capacitor doesnt discharge, hence the 3.3V signal isnt turning the IGBT ON (even for a short while, which would discharge the capacitor fully, and therefore even if I continue to apply 3.3V at HIN, after a short while I should measure 0V across the capacitor, which I do not).
- I would like to stick with N channel and not P channel (because I have them ready for implementation).
- Would really like to use isolated DC-DC converter power supply (either use it individually to connect it to the gate and emitter of the IGBT and switch the converter ON and OFF) or integrate it with IR2101 somehow. (Need help in this application)
- Lastly if nothing works try using charge pump circuitry and integrate that circuitry with the current gate driver I have. (Need help in this application)
Your response will be extremely helpful to me.