The recommended bias supply voltage range for LMG2100R026 is from 4.75V to 5.25V. Note that the gate voltage of the low-side GaN FET is not clamped internally. Hence, it is important to keep the VCC bias supply within the recommended operating range to prevent exceeding the low-side GaN transistor gate breakdown voltage.

The UVLO protection feature also involves a hysteresis function. This means that once the device is operating in normal mode, if the VCC voltage drops, the device continues to operate in normal mode as far as the voltage drop does not exceeds the hysteresis specification, V_CC(hyst). If the voltage drop is more than hysteresis specification, the device shuts down. Therefore, while operating at or near the 4.5V range, the voltage ripple on the auxiliary power supply output must be smaller than the hysteresis specification of LMG2100R026 to avoid triggering device-shutdown.

Place a local bypass capacitor between the VCC and AGND pins. This capacitor must be located as close as possible to the device. A low ESR, ceramic surface-mount capacitor is recommended. TI recommends using two capacitors across VCC and AGND: a 100nF ceramic surface-mount capacitor for high frequency filtering placed very close to VCC and AGND pin, and another surface-mount capacitor, 220nF to 10μF, for IC bias requirements.