Using 6 TLP250 how to solve dead time for BLDC motor driver

[PRABAKARDEVA]

https://obrazki.elektroda.pl/1298082300_1474729855.jpg

Hai,
I am designing a BLDC motor driver by using TLP250 using STM32f402 micro-controller. Now i have been stuck with optocoupler output,after reading hall sensor output i have triggered one high level mosfet and one low level mosfet. But when i read gate voltage there is no such gate triggering voltage so i decided to check respective opto output pins.
These are my questions as well as problems that i'm facing :
1. From controller I m passing 50% of duty cycle value(as well as 95% too) before connecting to pin no 2 of opto it is 1.5V but after connecting to opto it sinks into 0.7V....why???

2. If we try use pull up resistor(220ohms) in between controller o/p to optocoupler input pin no 2 the voltage gets boosted up, when we connect it to pin 2 the problem remains same(0.7V in pin2)

3. If this problem comes due to lack of current from micro controller how to boost up current for opto.

 

[FvM]

I presume the TLP cathodes are directly connecting to STM32 IO pins?

STM32 GPIOs can basically source or sink the required TLP drive current. But the circuit is completely wrong.
- individual series resistors for each optocoupler required, power supply must be 3.3V
- high side drivers can't use common power supply, need either three DC/DC converters or bootstrap supply
- remove 1N4001 diodes

 

[PRABAKARDEVA]

I presume the TLP cathodes are directly connecting to STM32 IO pins?

No.....TLP Cathodes are connected to STM32 ground.
Anode is connected to STM32 PWM pin.

STM32 GPIOs can basically source or sink the required TLP drive current. But the circuit is completely wrong.
- individual series resistors for each optocoupler required, power supply must be 3.3V

I have checked with the individual series resistors for each optocoupler.since the voltage is sinking.

high side drivers can't use common power supply, need either three DC/DC converters or bootstrap supply
- remove 1N4001 diodes

As per your suggestion.removed the 1N4001 diodes and for high side drivers are not using common power supply

 

[JayantD]

Connect 10k 1/4W resistors between Gate-Emitter of each IGBT. This will prevent IGBT damage in case of control power supply failure.
JayantD

 

[PRABAKARDEVA]

Connect 10k 1/4W resistors between Gate-Emitter of each IGBT. This will prevent IGBT damage in case of control power supply failure.
JayantD

I had tried with 1k resistor.but the track of the board has burnt.

 

[KlausST]

Hi,

I doubt that the track burnt because of the 1k

Klaus

 

[FvM]

Presently we know only the faulty schematic linked in post #1 and (not completely clearly) indicated modifications in post #3. The final circuit isn't known, neither the applied pulse pattern. There has been yet no reference to a possible dead time problem implied in the thread title.

So according to my knowledge, something is wrong with hard- or software, and burned transistors and PCB may be the result.

 

[PRABAKARDEVA]

Presently we know only the faulty schematic linked in post #1 and (not completely clearly) indicated modifications in post #3. The final circuit isn't known, neither the applied pulse pattern. There has been yet no reference to a possible dead time problem implied in the thread title.

So according to my knowledge, something is wrong with hard- or software, and burned transistors and PCB may be the result.

Now i m in little bit progress in both hardware and software.Actually i am using Timer 1 in STM32F4 which has inbuilt dead time generator.I just generating the dead time by config the registers.So I can't able to doubt on dead time.

Due to dead time,Mosfet will burn?I will post the updated schematic.

- - - Updated - - -

Hi,

I doubt that the track burnt because of the 1k

Klaus

Initially i didn't put the 1k resistor.After I put 1k track got burnt.I'm not insist that because of 1k.May be it causes because of some other problem.