MPQ4228-C Step-Down Converter with Charging Port Monolithic Power Systems (MPS) MPQ4228-C Step-Down Converter with Charging Port integrates a single USB current-limit switch and a Type-C™ 5V at 3A mode configuration channel for USB ports. The device provides 3A output current across a wide input supply range, achieving excellent load/line regulation. The output on the switch is current-limited.