TIDA-01606: Gate driver issue

Mingi Oh

Intellectual 480 points

Part Number: TIDA-01606

Tool/software:

Dear TI,

I have a question about the TIDA-01606 gate driver.

It was working fine, but suddenly the gate driver output voltage intermittently disappears above 100V.

So, I did some investigation and found out that the buffer (SN74LVC126APWR) might have some issues.

When the gate signal from the MCU passes through the buffer, it intermittently loses the signal.

I have changed the buffer but it has the same issue.

Has this situation ever happened to you during testing? If you think there might be any other possible issues, please let me know.

By the way, when I checked the power (3.3V), it was okay.

3 months ago

0 Kelvin Le THS 3 months ago

TI__Expert 6725 points

Mingi,

this problem that you see only occurs when DCLink voltage>100V?

-Kelvin

0 Mingi Oh 3 months ago in reply to Kelvin Le THS

Intellectual 480 points

Mostly, above 300V.

I dont know what’s the problem.

should I change buffer again?

today, I changed the gate driver but it happened as same as before.

0 Kelvin Le THS 3 months ago in reply to Mingi Oh

TI__Expert 6725 points

you measured the supply rail with the scope when the voltage drops out and it was still 3.3V?

0 Kelvin Le THS 3 months ago in reply to Kelvin Le THS

TI__Expert 6725 points

also, i noticed during the that time window when the Gate_V_TOP is low, the Switch_V_Top (the switching node voltage?) recovers to high bus voltage before Gate_V_TOP is high again. this doesn't not make sense to me.

can you check to see if there is any fault reported by the gate driver on the FLT pin?

0 Mingi Oh 3 months ago in reply to Kelvin Le THS

Intellectual 480 points

It shows 3.3v on the main board.

It is hard to measure 3.3v on the gate driver board.

So if I remove the buffer, is it okay?

0 Mingi Oh 3 months ago in reply to Kelvin Le THS

Intellectual 480 points

1) I didn’t check the fault signal. But there was no red light on the gate driver boards.

but I will check it.

2) about the voltage recovery, I think it is reasonable. The current on the window is after the filter. So inverter current might be changed from negative and positive. In that case, the body diode would take the load current. So the direction of voltage was changed.

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TIDA-01606: Gate driver issue