SLUSDR3B June 2019 – February 2024 UCC5390-Q1
PRODUCTION DATA
When parasitic inductances are introduced by nonideal PCB layout and long package leads (such as TO-220 and TO-247 type packages), ringing in the gate-source drive voltage of the power transistor could occur during high di/dt and dv/dt switching. If the ringing is over the threshold voltage, unintended turn-on and shoot-through could occur. Applying a negative bias on the gate drive is a popular way to keep such ringing below the threshold. A few examples of implementing negative gate-drive bias follow.
Figure 8-2 shows another example which uses two supplies (or single-input, double-output power supply). The power supply across VCC2 and GND2 determines the positive drive output voltage and the power supply across VEE2 and GND2 determines the negative turn-off voltage. This solution requires more power supplies than the first example, however, it provides more flexibility when setting the positive and negative rail voltages.