DRV2700EVM: Driver damaged while testing

Part Number:DRV2700EVM

Hi

We have bought 4 pieces of DRV2700EVM recently, and tested them right after their arrival, finding that three of them worked well with correct amplification while the rest one only doubled the input voltage as output. After our first test, we went back to check whether the wrong amplification was induced from human error. Just after we connected and turned on the power supply of DRV2700EVM, a lot of smoke came out from the circuit board, and we turned off the power supply immediately. We then checked circuit and found one circuit line burning out.

        We want to make an exchange to our local supplier and they asked us to provide a complete test report to your engineers in order to check if any of the test step was wrong, leading to the failure of the circuit.

        Here are our test steps:

1. We set our jumpers as follows:

JP 2, 3, 4, 12, 13: Connected

JP 5, 6: Opened

JP7, 8, 9: PU

JP10, 11: VIN

1. Connect TP8 to ground and connect DC_IN to a voltage supply supporting continuous square wave signals ( the power of voltage supply is off). The square wave signals have peak to peak voltage of 2V along with a DC offset of 1V.
2. Connect J2’s + port to a 5V DC voltage power supply and – port to ground. ( The power supply is off.)
3. Connect the high voltage output to the Oscilloscope: Vin+ to Channel 1, Vin- to Channel 2, and GND to both channels’ ground. To assure Input and Output have a common ground, connect GND to TP8.
4. Turn on the voltage supply of J2 and turn on the power supply of DC_IN.
5. Check the result on the oscilloscope.

Since we didn’t record the output result of the wrong amplification signals before the circuit burned out, we can only provide the output signals of the rest well-functioning drivers and of the damaged drivers:

The yellow curve represents the signals of Ch1, while the blue curve represents the signals of Ch2.Both the signals show square wave with peak to peak voltage of 50V. The purple curve is the difference of signals in Ch1 and Ch2, revealing a square wave with peak to peak voltage of 100V (50X amplification rate).

        However, the damaged driver shows no amplification, even no output signal when measuring.

        Please leave any comment if find any incorrect setup or step in the test step description above. Thank you.