10.2.3 Reliable Bootstrap Start-up

In some applications such as boost converter, the low side LMG341xR070 may need to start switching at high frequency while high side LMG341xR070 is not fully biased. If low side GaN device turn-on speed is adjusted to achieve high slew rate, the high side GaN device can turn-on unintentionally as high dv/dt can charge high side GaN device drain to source capacitance. For reliable operation, the slew rate should be slowed down to 30 V/ns by changing the resistance of RDRV pin of the low side LMG341xR070 until high side LMG341xR070's bias is fully settled. This can be monitored through the FAULT output of high side LMG341xR070 as given in Figure 14.