Gate Driver ICs Forum Discussions

[gurusamy]

Hi,

We are using the Gate Driver IC part 1ED3122MU12HXUMA1 to Turn OFF the 1.2kV rated N-Channel MOSFET. 

During the High voltage Testing (1usec Pulse width, 1.2kV voltage switching at MOSFET), Gate driver output getting false Turn OFF.

Gate Driver output wave form does not comply with Gate Driver Input wave form. 

I have attached two images (Normal Working Condition and False condition). In wave form denotes Yellow Color - Gate Driver Output , Blue Color - Gate Driver Input.

What could be the reason for this False Output ? 

Kindly clarify this False Triggering scenario to rectify this issue.

At normal condition Vgs and gate driver inputFALSE CONDITION

Regards,

Gurusamy M (+91 9842897485)

Data Patterns (I) Ltd,

Chennai-603103, INDIA

[AZIZ_HASSAN]

Hello Guru,

Thanks for posting at Infineon community.

To look into your issue deeply, can you please share your test circuit and was  the false triggering not happening at voltage less than 1.2KV. In addition to it, can you please provide the device voltage and current (Vds, Id) waveform.

Best Regards,

AZIZ

[gurusamy]

Hi,

Herewith i have attached circuit of Gate Driver and MOSFET switching sections.

Kindly verify and provide your feed back for the impact of Gate driver output false Triggering.

Best Regard,

Gurusamy M

[gurusamy]

Hi,

I have attached the detailed circuit diagram and Test reports for further failure analysis.

Kindly provide your feedback quickly to solve this issue at earliest. Please let me know if any other details required.

Regards,

Gurusamy M

[gurusamy]

Hi AZIZ,

As discussed i have attached the Test Circuit and Test reports. Kindly support to resolve this issue.

Note : This issue happen randomly. Kindly let me know if any more details required.

Best Regards,

Gurusamy M

[AZIZ_HASSAN]

Hello Guru,

Thanks for your details. Can you please answer  whether this false turn off is happening only at 1.2kV or it is happening at lower voltage also. Along with this can you please share the test circuit schematic and the device voltage and current during false turn off and during normal operation for comparison.

Thanks and regrads,

AZIZ

[gurusamy]

Hi,

I have attached the detailed circuit diagram and Test reports for further failure analysis.

Kindly provide your feedback quickly to solve this issue at earliest. Please let me know if any other details required.

Regards,

Gurusamy M

[gurusamy]

Hi,

I have attached the detailed circuit diagram and Test reports for further failure analysis.

Kindly provide your feedback quickly to solve this issue at earliest. Please let me know if any other details required.

Regards,

Gurusamy M

[AZIZ_HASSAN]

Hello Guru,

May I know why you have connected a 2*512 ohm resistor between SGND and PGND. Its not recommended. Already there is a isolation between primary and secondary.  Please remove this circuit and test once.

Thanks and regards,

AZIZ

[gurusamy]

Hi Aziz,

As the HV SIC-MOSFET is connected with 40kV(DC) node,40kV isolation need to be provided bw Primary and Secondary of Gate driver IC(1ED3122MU12HXUMA1).

Since 1ED3122MU12HXUMA1 only supports isolation voltage of 5.7kV-rms(1min), 2x512 ohms used between primary and secondary to avoid the DC-voltage built-up. And voltage rating of each 512 ohms is 3kV -FYI

While HV switching operation, Voltage measured bw primary and secondary(ie.,bw PGND and SGND) was just ~800V,.

As per the attachment sent in our previous discussion,all measurements/waveform taken in 1ED3122MU12HXUMA1 are well within the range as recommended by the datasheet.

All the pin functionalities/parameters of gate driver IC seems to be ok, except output pin.-Refer the attachment.

What would be the cause of this abnormal behavior of 1ED3122MU12HXUMA1?

Note 1:Isolation bw primary and secondary supply of 1ED3122MU12HXUMA1 is maintained at least 20kV(min)

Note 2:All waveforms are taken only at gatedriver IC's pin only using battery operated oscilloscope.

Best Regards,

Gurusamy M

[AZIZ_HASSAN]

Hello Guru,

Thanks for your explanation. However, I hope you are using one driver IC for each switch i.e. total 40 driver IC is used. If so then you need not to connect the resistors. In fact the resistors behave as a  low resistor path(512*2 is low value) and might give some abnormalities. Rest the isolation told by you is correct.

Please try this and let me know.

Thanks and regards,

AZIZ

[gurusamy]

Dear Aziz,

As already mentioned, the primary and secondary supply which is given to gate driver IC is completely isolated and 40kV potential is connected with drain of SIC MOSFET.So there is a possibility of DC high voltage built-up(ie.,it may be >5kV) between primary and secondary.

And all the parameters and measurements w.r.t gate driver IC are well within the limit as recommended by the datasheet.

As you seen that,only output of the gate-driver is completely goes OFF at 300th nano-sec and never turned ON again,even the input pulse-width is 1usec

So that only we are asking that, Is there any possibility of condition in which the driver output goes OFF permanently.

Please do the needful to resolve the issue.

Best Regards,

Gurusamy M