BU90104GWZ 1A Switching Regulator Rohm Semiconductors BU90104GWZ 1A Switching Regulator is a high efficiency 6MHz synchronous step-down switching regulator with an ultra-low current PFM mode. The BU90104GWZ provides up to 1A load current and an input voltage range from 3.0V to 5.5V. The BU90104GWZ from ROHM is optimized for battery-powered portable applications. This device includes a mode control pin that allows the user to select Forced PWM (Pulse Width Modulation) mode or PFM (Pulse Frequency Modulation) and PWM auto-change mode, utilized power save operation at light load current.