TY  - CHAP
U1  - Konferenzveröffentlichung
A1  - Seidel, Achim
A1  - Wicht, Bernhard
ED  - Fujino, Laura
T1  - A fully integrated three-level 11.6nC gate driver supporting GaN gate injection transistors
T2  - 2018 IEEE International Solid-State Circuits Conference : digest of technical papers
N2  - Due to their superior fast-switching performance, GaN transistors show enormous potential to enable compact power electronics in applications like renewable energy, electrical cars and home appliances by shrinking down the size of passives. However, fast switching poses challenges for the gate driver. Since GaN transistors have a low threshold voltage Vt of ~1V, an unintended driver turn-on can occur in case of a unipolar gate control as shown for a typical half-bridge in Fig. 24.2.1 (top left). This is due to coupling via the gate-drain capacitance (Miller coupling), when the low-side driver turns on, causing a peak current into the gate. This is usually tackled by applying a negative gate voltage to enhance the safety margin towards Vt, resulting in a bipolar gate-driving scheme. In many power-electronics applications GaN transistors operate in reverse conduction, carrying the inductor current during the dead time t, when the high-side and low-side switch are off (as illustrated at a high-side switch in Fig. 24.2.1, bottom left). As there is no real body diode as in silicon devices, the GaN transistor turns on in reverse operation with a voltage drop VF across the drain-source terminals (quasi-body diode behavior). As a negative gate voltage adds to VF, 63% higher reverse-conduction losses were measured for a typical GaN switch in bipolar gate-drive operation. This drawback is addressed by a three-level gate voltage (positive, 0V, negative), which at the same time provides robustness against unintended turn-on similar to the bipolar gate driver, proven in [1] for a discrete driver.
Y1  - 2018
U6  - https://doi.org/10.1109/ISSCC.2018.8310345
DO  - https://doi.org/10.1109/ISSCC.2018.8310345
SP  - 384
EP  - 386
S1  - 3
PB  - IEEE
CY  - Piscataway, NJ
ER  -