Driver board of MTRCKTSBNG128 Development kit

[yaletron]

Hi 

We use MTRCKTSBNG128 Development kit for BLDC motor control.

3-Phase Sensorless BLDC Development Kit|NXP

MTRCKTSBNG128 is designed for small motor application.  We are trying to use the dev kit to drive a bigger motor.  So we use 6 large power MOSFETs externally to replace the original small MOSFETs on driver board of MTRCKTSBNG128.  The larger power MOSFET part number is  IPB180N10S4-02 from Infineon.  Do I need to change any drive circuit of drive board with drive IC MC33397A after we replace the MOSFETs?  or Is that okay to just replace MOSFETs without changing MOSFETs gate resistors?  See datasheet below.

http://www.infineon.com/dgdl/Infineon-IPB180N10S4_02-DS-v01_00-en.pdf?fileId=db3a30433d1d0bbe013d212...

IPB180N10S4-02 MOSFET is from Infineon, its gate charge total Qg is 156 nC typical, 200 nC max.  I think MC33397A can drive MOSFET up to Qg max 300 nC, see datasheet below.

http://www.nxp.com/files/analog/doc/data_sheet/MC33397.pdf

So far we did use IPB180N10S4-02 MOSFETs as external power board to replace original MOSFEts on Driver board, we didn't change any gate resistor circuits between drive IC and MOSFET gate,  but MOSFET driver IC MC33397A failed.  the failure mode was driver IC MC33397A ran hot and blowed MOSFETs. 

I appreciate your help to define the problem and cause.   Any suggestions?

Thank you so much in advance

John

[RadekS]

Hi John,

Unfortunately is hard to say what might be a reason for that result. There aren’t enough details about that issue.

Since IPB180N10S4-02 use different package, you probably cannot assemble it on power stage board directly. How did you connect it?

In fact, the MC33397A and transistors should be placed as close as possible for avoiding transient effects.

I suppose that original code with original transistors and original motor worked fine. Correct?

Did you test the original code with changed transistors and original motor? Did it work?

Or you change transistors and connected directly also high power motor?

The failure happened immediately after connecting to the power supply/ after the start of motor control program/after some speed change/in high power mode?

Do you have any measurements result from testing?

The Maximum Input Differential Voltage for Current Sense Amplifier is just +/-800mV. So, even short term current higher than 53A may damage Current Sense Amplifier (assembled shunt is 0.015Ohm).

Have a great day,
RadekS

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[yaletron]

Hi Radek,

Thanks for the feedback.

Here is the schematic to show how power board (6 MOSFET IPB180N10S4-02 ) is connected externally.  Basically, we remove the original 6 small MOSFETs from drive board, then connect Gate of IPB180N10S4-02 to gate of original small MOSFETs by 6 wires (PA_HSG. PB_HSG....) accordingly. 

We used the original small motor and code for testing.  We only changed MOSFETs to test system before we use big motor.

The motor was running, but speed is stable, then we found MC33397A running hot after short time.  We thought MC33397A may not able to drive the big MOSFETs IPB180N10S4-02 .  In order to prove this, we use orginal small MOSFETs to replace big MOSFTEs, then we found MC33397A running hot also, we stopped, and found a small MOSFET shorted. 

We have used two MC33397A board and failed twice.  So before we try again, we would like to make sure to find root cause.  Is MC33397A able to drive MOSFETs IPB180N10S4-02?   Do you think our way to replace small MOSFET is okay?  Or should we change resistor value between MC33397A output and gate of each big MOSFET since big MOSFET gare impedance is different from small MOSFET? 

Thank you

John