System and method for detecting electrical connection and disconnection on USB Type-A charging port

A system for detecting electrical connection and disconnection on an Universal Serial Bus (USB) type-A charging port of an USB device comprising one or more USB ports, the system comprising:

• a power source;
• a MOSFET (metal oxide semiconductor field effect transistor) switch gate driver configured to, in an USB type-A connected state, operatively couple a MOSFET SWITCH with the power source and a VBUS supply of the USB type-A port of the USB device;
• a current sense differential amplifier operatively coupled to the USB device;
• a charge pump operatively coupled to the USB device and configured to, upon activation, maintain a VBUS voltage at around 5V and a current within a first range of values;
• a voltage sense operatively coupled with the USB device and configured to sense VBUS voltage;
• and
• a control unit comprising one or more processors and a memory coupled with the one or more processors, the memory storing instructions executable by the one or more processors to:
• monitor, using the current sense differential amplifier, VBUS current flowing on a VBUS pin of the USB device, in an USB type-A connected state, through an external sense resistor, and amplify the monitored VBUS current, wherein when the monitored VBUS current is less than a predetermined current for a pre-configured time window, detect a potential disconnected state of the connected USB type-A port;
• and
• monitor, using the voltage sense, the VBUS voltage to compare the monitored VBUS voltage with a predetermined voltage to sense an external condition such that VBUS voltage drops from a load capacitance and a load current, and wherein when the VBUS voltage drops below the predetermined voltage, detect the USB type-A connected state;
• wherein in the USB type-A potential disconnected state, the control unit is configured to enable and disable the MOSFET switch in cycles such that when the MOSFET switch is enabled, an output VBUS capacitor is charged to 5V and when the MOSFET switch is disabled, the output VBUS capacitor provides power to a load through the connected USB type-A port.