LMG3410-HB-EVM：LMG3410 Switch signal problem

Hello,

綱瑋 范 said:

If The sub-board LMG3410-HB-EVM only connects to a 5V auxiliary power supply. There are signals on the gates of Q1 and Q2. Pin 13 of U1 is 0V, and pin 14 is 5V. Both pins 13 and 14 on the lower arm are 5V, and the Vgs is also 5V.

Correct

綱瑋 范 said:

If a duty = 0 switching signal is connected, the gate voltages of Q1 and Q2 can be reduced to 0. At this time, pins 13 and 14 of U1 are both at 1.5V, pin 13 of U2 is 0V, and pin 14 is 5V, so Vgs = 0V. If an input voltage (AC source) is applied to the motherboard, the current will be very small, occurring only in the positive half cycle.

At this time, pins 13 and 14 of U1 are both at 0V because the pin 5 & 6 on J1 Aux connected (PWM signals for TOP FET and Bot FET are 0), everything else is correct.

What is the concern here? As the board seems to working as expected.

Best,

Pratik A.

Hi Pratik,

We get the wrong gate driver, ISO7831DWR, so the outputs of gate driver is high level if the input is open.

Thanks.

Best,

Brong.

Hi Pratik,

We have replaced the correct get driver and the problem was indeed due to replacing the wrong get driver.

Thanks.

Best,

Brong.