High-Frequency Three-Level Gate Driver for GaN HEMT Bridge Crosstalk Suppression

In order to suppress the crosstalk in gallium nitride (GaN)-based bridge configuration, this article proposes a novel high-frequency three-level gate driver (HFTGD), and the crosstalk suppression with switching frequency up to 5 MHz can be achieved. The capacitor-diode circuit generates a negative voltage to prevent the false turn-ON of the device under the impact of positive crosstalk. Pulsewidth modulation generator works together with comparator circuit to rapidly clamp the negative voltage to zero level, thereby suppressing the negative crosstalk. In particular, HFTGD utilizes only two passive components to produce the negative voltage and also has the advantages of good high-frequency stability and adjustable negative voltage depth. The control signal of the zero-level clamp circuit is digitally implemented, resulting in a shorter clamp time and minimal impact on the switching speed of the GaN high electron mobility transistor (HEMT). In addition, only a single power supply and a single control signal are required for HFTGD, which reduces the cost and control complexity. The effectiveness of HFTGD for positive and negative crosstalk suppression is demonstrated in a double-pulse test based on GS66504B.