Enable power from an accessory to a host device based on whether the accessory is able to alter an electrical characteristic of the power path
First Claim
1. A method of enabling a power path between a power source and a host device, comprising:
- sending, from the host device to an accessory arranged within the power path, via a first data pin arranged in the host device, a request for an accessory identifier, the accessory identifier identifying the accessory;
determining whether the accessory identifier is received from the accessory within a specified period of time and whether a received accessory identifier is valid;
if it is determined that the accessory identifier is received from the accessory within the specified period of time, and if the accessory identifier is valid;
enabling a power path between the accessory and the host so that the host receives power from the accessory;
measuring a first voltage level at a power pin;
sending an instruction to the accessory to alter an electrical characteristic of the power path;
measuring a second voltage level at the power pin; and
if the second voltage is less than the first voltage, enabling power received over the power path to at least one of;
charge a battery of the host device or operate the host device.
1 Assignment
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Accused Products
Abstract
Methods, systems, and apparatus for enabling a power path between a power source and a host device via an accessory. A host device may send, to an accessory arranged within the power path, via a first data pin arranged in the host device, a request for an accessory identifier. The accessory identifier identifies the accessory. The host device may then determine whether the accessory identifier is received from the accessory within a specified period of time or whether a received accessory identifier is valid. If the accessory identifier is not received from the accessory within the specified period of time, or a received accessory identifier is not valid, the host device sends a new request for the accessory identifier to the accessory via a second data pin different than the first data pin.
71 Citations
11 Claims
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1. A method of enabling a power path between a power source and a host device, comprising:
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sending, from the host device to an accessory arranged within the power path, via a first data pin arranged in the host device, a request for an accessory identifier, the accessory identifier identifying the accessory; determining whether the accessory identifier is received from the accessory within a specified period of time and whether a received accessory identifier is valid; if it is determined that the accessory identifier is received from the accessory within the specified period of time, and if the accessory identifier is valid; enabling a power path between the accessory and the host so that the host receives power from the accessory; measuring a first voltage level at a power pin; sending an instruction to the accessory to alter an electrical characteristic of the power path; measuring a second voltage level at the power pin; and if the second voltage is less than the first voltage, enabling power received over the power path to at least one of;
charge a battery of the host device or operate the host device. - View Dependent Claims (2, 3, 4)
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5. A host device comprising:
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a power pin operable to receive a voltage from an accessory; a connector having a plurality of contacts; and control circuitry operable to; send, via one or more of the contacts to the accessory, a request for an accessory identifier, the accessory identifier identifying the accessory; determine whether the accessory identifier is received from the accessory within a specified period of time of and whether a received accessory identifier is valid; if it is determined that the accessory identifier is received from the accessory within the specified period of time, and if the accessory identifier is valid; enable a power path between the accessory and the host so that the host receives power from the accessory; measure a first voltage level at a power pin; send an instruction to the accessory to alter an electrical characteristic of the power path; measure a second voltage level at the power pin; and if the second voltage is less than the first voltage, enable power received over the power path to at least one of;
charge a battery of the host device or operate the host device. - View Dependent Claims (6, 7, 8)
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9. An accessory, comprising:
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a power pin operable to provide power to a host device; a data pin operable to receive an instruction from the host device; and power limiting circuitry operable to; monitor the data pin; determine that the instruction is received over the data pin; in response to the instruction being a request for an accessory identifier that identifies the accessory from the host device, send a response that communicates the accessory identifier to the host device, and enable, at the accessory, a power path between a power source and the host device; and in response to the instruction being a request, via the data pin, to alter an impedance of the power path after the power path is enabled, alter the impedance of the power path, wherein the power limiting circuitry includes impedance altering circuitry arranged between the power pin and the power source, and identification circuitry arranged between the data pin and the impedance altering circuitry, and wherein the identification circuitry is operable to instruct the impedance altering circuitry to reduce the impedance of the power path between the power source and the host device concurrently with communicating the accessory identifier to the host device. - View Dependent Claims (10, 11)
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Specification