I have a problem with the L6498D driver, the high-side does not work

[WPazH]

design a driver for full h-bridge using two L6498D, when i activate the LIN input the LVG output is activated and manages to turn on the low side MOSFET, but when i activate the HIN input i get a strange output of 9.6v on HVG and i am using 12v at VCC of the L6498D. This strange voltage level always appears, when I always keep the HIN input high or when there is a PWM in HIN, in both situations the HVG output is always the same, 9.6v. What could be happening?

 

 

[Andrea Francesco MERELLO]

Hi,

did you solve the problem in the meantime?

In order to work properly, the bootstrap structure requires LIN to be active and consequently OUT/S1 pin connected to GND for the time needed to pre-charge the bootstrap capacitor.

With an external bootstrap diode, alternatively, the circuit topology/load should allow the OUT/S1 pin to go at GND level (or less) from time to time in order to achieve the same result.

Every time HIN is activated, there should be a residual charge/voltage in the bootstrap capacitor which is higher than the UVLO turn-on threshold (max).

I hope this (so late answer) helps,

Regards