Where is 3.3V or 5V coming from?

[IGücl.1]

I have a STEVAL-IPM05F. My goal is to switch on/off the IGBTs. While I try that, I got many difficulties, like loading the Boots voltage etc. Now I have four questions.

1. Why are all of the bootstrap capacitors carched although I don't switch the LOW-Side on?
2. What is the SD here (Where can I measure when an error is there?). I put it on high or in low and nothing changes.
3. Where does the powerboard gets his 3.3V or 5V? If I look at the circuit, there isn't anything which generates the 3.3V or 5V.
4. I have an +V and HV bus voltage pin on the motor control connector and there isn't any description in the user manuel or in the internet. What do they stand for?

Pls a good answer is very important, because in my last question the answer was wrong and I tried to test the board with that answer and lost a lot of time.

Thank you!

[Tesla DeLorean]

5V via header

3.3V via header

From User Manual

"The board requires +5 V and +3.3 V to be supplied externally through the 34-pin motor control connector J2. Please refer to the relevant board manuals for information on key connections and supplies."

https://www.st.com/resource/en/user_manual/um1971-500-w-motor-control-power-board-based-on-stgif5ch60tsl-sllimm-2nd-series-ipm-stmicroelectronics.pdf

https://www.st.com/resource/en/schematic_pack/steval-ipm05f_schematic.pdf

[Gigi]

Ciao

1. I think that is not possible that the boot capacitors are changed if you don't turn on the low side. I'm assuming that you are also providing some DC bust voltage. Normally the phase output, that is connected with the negative pins of the boot capacitors is set to VDCBus / 2. Saying that if you are providing a bus voltage that is below 30V and you supply the +15V for the gate driver then the bootstrap diode (if present on the board) will charge the capacitors.
2. The SD pin is normally used for the over current protection using the Cin connected to a shunt resistor. It is normally pull up at 3.3V if no fault occur or have a low voltage when the overcurrent occurs.
3. Already answered by Tesla DeLorean
4. Can you explain where you can read +V and HV bus voltage pin on the motor control. I don't find it.

Ciao

Gigi

[IGücl.1]

When I look in the manuals, the 34-pin on J2 is the "measure phase C"-pin. This does't make sense to me. Is it possible to explain it, why this is the correct one?

[IGücl.1]

1. Thank you! I will check it.
2. My SD pin is by 0V. In that case I have a fault ...
3. I reply to him.
4. It is listed at the motor control connector J2 in the same board manual, which Tesla DeLorean sent. The +V Power is the Pin 25 and the HV Bus Voltage the pin 14.

[IGücl.1]

After I read your answer again I checked that you mean not the 34. pin. Sry! which on of the pin is the Input pin for 3.3/5V? Thank you!

[Gigi]

Ciao

If the SD pin is 0V even if you provide the signal to turn ON the power switches, they will not turned on (it is a safety feature). Normally this pin is pullup to +3.3V using a resistor, but if you don't provide the +3.3V to the J2 pin 28 this pin will be always zero volt.

Considering the Table 6 of the manual

pin 25 +V power. You have to provide to this pin +5V

pin 28 Vdd_m.You have to provide to this pin the 3.3V

pin 14 HV bus voltage. This is a signal for the microcontroller to monitor the DC bus voltage. In the board is done using the voltage divider composed by R1, R2 and R4

Ciao

Gigi

[IGücl.1]

Thank you!

[IGücl.1 · Accepted solution]

After I connected the 3.3V to the correct J2 Pin, I get a voltage between the two ends of the same cable. My control board is connected to my laptop with a galvanic isolation and the laptop is not pluged, the powerboard is connected to a voltage generator (15-20V) and the grounds from the power and control board are connected to each other too. Why am I get a potential difference between pin 28 and 3.3V pin from the control board, when they are connected ?

Thank you

Ismail