Abstract: Universal Serial Bus (USB) cable type detection and control techniques are disclosed. In an exemplary aspect, a device connected to a cable detects whether the cable is a legacy cable (i.e., a Type-A to Type-C cable). If the cable is a legacy cable, the device determines an appropriate current to draw based on whether the cable is compliant with the USB Type-C specification or non-compliant. Additional exemplary aspects of the present disclosure determine whether a connector adaptor has been put on a legacy cable and determines an appropriate current to draw based on the capabilities of the legacy cable. Still further aspects of the present disclosure evaluate not only the cable to see if the cable limits the current draw, but also evaluate a device at a distal end of the cable to verify if and how current may be drawn by such remote device from a mobile terminal.

Abstract: Certain aspects of the present disclosure generally relate to reducing the size of parallel charging circuits for charging a battery in a portable device, while still effectively providing input current sensing and reverse current blocking capabilities. One example battery charging circuit generally includes: (1) a first charging circuit comprising a first charging output connectable to a battery and a first converter to provide power to the first charging output; and (2) a second charging circuit comprising a second charging output connectable to the battery, a second converter to provide power to the second charging output, a first transistor coupled between an output of the second converter and the second charging output, and a current-sensing circuit coupled to the output of the second converter to sense a current through the first transistor.

Abstract: Over-voltage protection systems and methods are disclosed. In one aspect, a biasing circuit is added to a pre-existing clamp required by the Universal Serial Bus (USB) Type-C specification at a configuration control (CC) pin. The biasing circuit turns the pre-existing clamp into an adjustable clamp that dynamically adjusts to over-voltage conditions. In an exemplary aspect, the biasing circuit may include a biasing field effect transistor (FET) and a pair of switches that selectively couple the pre-existing clamp and the biasing FET to fixed voltages such that the CC pin is maintained at an acceptable voltage. In another exemplary aspect, the biasing circuit may omit the biasing FET and rely on two switches that selectively couple the pre-existing clamp to fixed voltages such that the CC pin is maintained at an acceptable voltage.

Abstract: Certain aspects of the present disclosure generally relate to reducing the size of parallel charging circuits for charging a battery in a portable device, while still effectively providing input current sensing and reverse current blocking capabilities. One example battery charging circuit generally includes: (1) a first charging circuit comprising a first charging output connectable to a battery and a first converter to provide power to the first charging output; and (2) a second charging circuit comprising a second charging output connectable to the battery, a second converter to provide power to the second charging output, a first transistor coupled between an output of the second converter and the second charging output, and a current-sensing circuit coupled to the output of the second converter to sense a current through the first transistor.

Abstract: Systems, methods, and apparatus for testing devices adapted for connection to other devices using universal serial bus (USB) are disclosed. Devices to be tested are caused to enter a special mode of operation when resistance measured at one or more terminals of a USB Type-C connector have values associated with the special mode of operation. One or more operations of the device are automatically initiated when the resistance coupled to the at least one terminal of the connector has a measured value that matches one of a set of resistance values maintained by the device. The one or more operations may include configuring a power management circuit based on the measured value, and entering a mode of operation that controls startup of at least one processor on the device when the measured value matches a first resistance value.

Abstract: Universal Serial Bus (USB) cable type detection and control techniques are disclosed. In an exemplary aspect, a device connected to a cable detects whether the cable is a legacy cable (i.e., a Type-A to Type-C cable). If the cable is a legacy cable, the device determines an appropriate current to draw based on whether the cable is compliant with the USB Type-C specification or non-compliant. Additional exemplary aspects of the present disclosure determine whether a connector adaptor has been put on a legacy cable and determines an appropriate current to draw based on the capabilities of the legacy cable. Still further aspects of the present disclosure evaluate not only the cable to see if the cable limits the current draw, but also evaluate a device at a distal end of the cable to verify if and how current may be drawn by such remote device from a mobile terminal.

Abstract: Over-voltage protection systems and methods are disclosed. In one aspect, a biasing circuit is added to a pre-existing clamp required by the Universal Serial Bus (USB) Type-C specification at a configuration control (CC) pin. The biasing circuit turns the pre-existing clamp into an adjustable clamp that dynamically adjusts to over-voltage conditions. In an exemplary aspect, the biasing circuit may include a biasing field effect transistor (FET) and a pair of switches that selectively couple the pre-existing clamp and the biasing FET to fixed voltages such that the CC pin is maintained at an acceptable voltage. In another exemplary aspect, the biasing circuit may omit the biasing FET and rely on two switches that selectively couple the pre-existing clamp to fixed voltages such that the CC pin is maintained at an acceptable voltage.

Abstract: Systems, methods, and apparatus for testing devices adapted for connection to other devices using universal serial bus (USB) are disclosed. Devices to be tested are caused to enter a special mode of operation when a resistance measured across across two terminals of a USB Type-C connector has a value associated with the special mode of operation. One or more operations of the device are automatically initiated when the resistance between the two terminals has a measured value that matches one of a set of resistance values maintained by the device. The one or more operations may include configuring a power management circuit based on the measured value, and entering a special or factory boot mode that controls startup of at least one processor on the device based on the measured value. Each of the set of resistance values exceeds a minimum open-circuit resistance value specified for the connector.

Abstract: Systems, methods, and apparatus for testing devices adapted for connection to other devices using universal serial bus (USB) are disclosed. Devices to be tested are caused to enter a special mode of operation when resistance measured at one or more terminals of a USB Type-C connector have values associated with the special mode of operation. One or more operations of the device are automatically initiated when the resistance coupled to the at least one terminal of the connector has a measured value that matches one of a set of resistance values maintained by the device. The one or more operations may include configuring a power management circuit based on the measured value, and entering a mode of operation that controls startup of at least one processor on the device when the measured value matches a first resistance value.

Abstract: Systems, methods, and apparatus for testing devices adapted for connection to other devices using universal serial bus (USB) are disclosed. Devices to be tested are caused to enter a special mode of operation when a resistance measured across two terminals of a USB Type-C connector has a value associated with the special mode of operation. One or more operations of the device are automatically initiated when the resistance between the two terminals has a measured value that matches one of a set of resistance values maintained by the device. The one or more operations may include configuring a power management circuit based on the measured value, and entering a special or factory boot mode that controls startup of at least one processor on the device based on the measured value. Each of the set of resistance values exceeds a minimum open-circuit resistance value specified for the connector.