Abstract: Systems, apparatuses, and methods for detecting a foreign object on a wireless power charging region are described. A circuit can detect an object inductively coupled to a wireless power transmitter. The circuit can further measure an input parameter prior to a power transfer stage, the input parameter can be one of an input current and an input power. The circuit can further compare the measured input parameter with a predetermined value. The circuit can further determine whether the object is a foreign object or the wireless power receiver based on a result of the comparison between the measured input parameter with the predetermined value.

Abstract: A method of over-current protection in a wireless power receiver operating in a high-power mode includes digitally receiving an output current signal, generating an OC INT signal if the output current signal is greater than a current limit value, and if the OC INT signal is generated, transmitting Count A number of End Power Transfer (EPT) packets. If wireless power transmission has not stopped, transmitting Count C number of Control Error Packets (CEPs) with Value B. If wireless power transmission has not reduced such that the output current IL is below the current limit value, then enabling an LDO current limit circuit in a power block of the wireless power receiver. In a low-power mode, the receiver enables a hardware over-current circuit that generates an OC INT signal when the output current exceeds a current limit.

Abstract: An authentication method for authenticating a wireless power transmitter to a wireless power receiver includes receiving a SSP value, an ID, and a random number RND from a wireless power receiver; determining an index based on the RND; choosing a base code from a set of base codes according to the index; determining a secure code from the base code, the index, the RND, the SSP value, and the ID; and transmitting the secure code to the wireless power receiver. A further method includes receiving a secure code from the wireless power transmitter; retrieving an index from the secure code; determining a base code from a set of base codes according to the index; calculating a second secure code; and authenticating the wireless power transmitter by comparing the secure code and the second secure code.

Abstract: A method of over-current protection in a wireless power receiver operating in a high-power mode includes digitally receiving an output current signal, generating an OC INT signal if the output current signal is greater than a current limit value, and if the OC INT signal is generated, transmitting Count A number of End Power Transfer (EPT) packets. If wireless power transmission has not stopped, transmitting Count C number of Control Error Packets (CEPs) with Value B. If wireless power transmission has not reduced such that the output current IL is below the current limit value, then enabling an LDO current limit circuit in a power block of the wireless power receiver. In a low-power mode, the receiver enables a hardware over-current circuit that generates an OC INT signal when the output current exceeds a current limit.