Apparatuses and methods to distinguish proprietary, non-floating and floating chargers for regulating charging currents

摘要

Apparatuses and methods to distinguish proprietary, non-floating and floating chargers for regulating charging current are disclosed. In one aspect, a charger detection circuit is provided in a portable electronic device. The charger detection circuit is configured to detect whether a connected Universal Serial Bus (USB) charger is compliant with a USB battery charging specification. If the connected USB charger is non-compliant with the USB battery charging specification, the charger detection circuit is configured to further detect if the non-complaint USB charger is a non-compliant floating USB charger or a non-compliant proprietary USB charger. If the connected USB charger is determined to be a non-compliant proprietary USB charger, the portable electronic device can be configured to draw up to a maximum charging current according to the USB battery charging specification.

主权项

1. A Universal Serial Bus (USB) charger detection circuit, comprising:
a detection control circuit configured to initiate a timeout timer in response to receipt of a VBUS signal from a connected USB charger and generate a timeout output indicative of an expiration of the timeout timer; and a comparison circuit configured to:
receive a data input signal based on a received USB data pin signal selected between a first data pin signal and a second data pin signal from the connected USB charger;receive a reference signal generated in response to detection of the VBUS signal from the connected USB charger; andgenerate a comparator output based on a comparison of the data input signal and the reference signal; the detection control circuit is further configured to generate a detection output indicative of the connected USB charger being a proprietary USB charger if the comparator output indicates the data input signal is greater than the reference signal.