Multiprotocol USB Adaptive Charging
A system includes a power source, a universal serial bus (USB) type C port, and a multi-protocol adaptive circuit. The multi-protocol adaptive circuit may be configured to determine that a USB element has attached to the USB type C port, to determine whether to apply a USB type C charging protocol to the USB element or a legacy USB type A charging protocol to the USB element, and to provide power from the power source to the USB element.
1 . An apparatus, comprising:
a universal serial bus (USB) type C port; and
a multi-protocol adaptive circuit configured to:
determine that a USB element has attached to the USB type C port; and
determine whether to apply a USB type C charging protocol to the USB element or a legacy USB type A charging protocol to the USB element.
2 . The apparatus of claim 1 , wherein, in order to determine whether to apply a USB type C charging protocol or a legacy USB type A charging protocol to the USB element, the multi-protocol adaptive circuit is further configured to:
send source capabilities to the USB element;
evaluate a reaction of the USB element in response to the sent source capabilities; and
determine whether to apply a USB type C charging protocol or a legacy USB type A charging protocol to the USB element based upon the reaction.
3 . The apparatus of claim 2 , wherein the multi-protocol adaptive circuit is further configured to determine to apply a legacy USB type A charging protocol to the USB element based upon the reaction of the USB element, the reaction to include no reply.
4 . The apparatus of claim 1 , wherein the multi-protocol adaptive circuit is further configured to determine that the USB element is a USB type A element connected through an adapter to the USB type C port.
5 . The apparatus of claim 4 , wherein the multi-protocol adaptive circuit is further configured to apply a legacy USB type A charging protocol to the USB element based upon the determination that the USB element is a USB type A element connected through the adapter to the adapter to the USB type C port.
6 . The apparatus of claim 1 , wherein upon a determination that a legacy USB type A charging protocol is to be applied to the USB element, the multi-protocol adaptive circuit is further configured to apply a series of a plurality of candidate legacy USB type A charging protocols to the USB element to determine a best protocol among the candidate legacy USB type A charging protocols to be used by the USB element.
7 . The apparatus of claim 6 , wherein the multi-protocol adaptive circuit is configured to:
apply the series of candidate legacy USB type A charging protocols through, for each candidate legacy USB type A charging protocol, application of test voltages to a D+ line and a D− line connected between the USB type C port and the USB element, the test voltages associated with the candidate legacy USB type A charging protocol, the series of candidate legacy USB type A charging protocols ordered according to charging power; and
based upon a determination that the USB element has applied a pull-up resistor in response to the test voltages, determine that a China mode legacy USB type A charging protocol is be used by the USB element.
8 . A method, comprising:
determining that a USB element has attached to a universal serial bus (USB) type C port; and
determining whether to apply a USB type C charging protocol to the USB element or a legacy USB type A charging protocol to the USB element.
9 . The method of claim 8 , wherein determining whether to apply a USB type C charging protocol or a legacy USB type A charging protocol to the USB element includes:
sending source capabilities to the USB element;
evaluating a reaction of the USB element in response to the sent source capabilities; and
determining whether to apply a USB type C charging protocol or a legacy USB type A charging protocol to the USB element based upon the reaction.
10 . The method of claim 9 , further comprising determining to apply a legacy USB type A charging protocol to the USB element based upon the reaction of the USB element, the reaction to include no reply.
11 . The method of claim 8 , further comprising determining that the USB element is a USB type A element connected through an adapter to the USB type C port.
12 . The method of claim 11 , further comprising applying a legacy USB type A charging protocol to the USB element based upon the determination that the USB element is a USB type A element connected through the adapter to the adapter to the USB type C port.
13 . The method of claim 8 , further comprising, upon a determination that a legacy USB type A charging protocol is to be applied to the USB element, applying a series of a plurality of candidate legacy USB type A charging protocols to the USB element to determine a best protocol among the candidate legacy USB type A charging protocols to be used by the USB element.
14 . The method of claim 13 , further comprising:
applying the series of candidate legacy USB type A charging protocols through, for each candidate legacy USB type A charging protocol, application of test voltages to a D+ line and a D− line connected between the USB type C port and the USB element, the test voltages associated with the candidate legacy USB type A charging protocol, the series of candidate legacy USB type A charging protocols ordered according to charging power; and
based upon a determination that the USB element has applied a pull-up resistor in response to the test voltages, determining that a China mode legacy USB type A charging protocol is be used by the USB element.
15 . A system, comprising:
a power source;
a universal serial bus (USB) type C port;
a multi-protocol adaptive circuit configured to:
determine that a USB element has attached to the USB type C port;
determine whether to apply a USB type C charging protocol to the USB element or a legacy USB type A charging protocol to the USB element; and
cause power to be provided from the power source to the USB element using a selected charging protocol.
16 . The system of claim 15 , wherein, in order to determine whether to apply a USB type C charging protocol or a legacy USB type A charging protocol to the USB element, the multi-protocol adaptive circuit is further configured to:
send source capabilities to the USB element;
evaluate a reaction of the USB element in response to the sent source capabilities; and
determine whether to apply a USB type C charging protocol or a legacy USB type A charging protocol to the USB element based upon the reaction.
17 . The system of claim 16 , wherein the multi-protocol adaptive circuit is further configured to determine to apply a legacy USB type A charging protocol to the USB element based upon the reaction of the USB element, the reaction to include no reply.
18 . The system of claim 15 , wherein the multi-protocol adaptive circuit is further configured to determine that the USB element is a USB type A element connected through an adapter to the USB type C port.
19 . The system of claim 18 , wherein the multi-protocol adaptive circuit is further configured to apply a legacy USB type A charging protocol to the USB element based upon the determination that the USB element is a USB type A element connected through the adapter to the adapter to the USB type C port.
20 . The system of claim 15 , wherein upon a determination that a legacy USB type A charging protocol is to be applied to the USB element, the multi-protocol adaptive circuit is further configured to apply a series of a plurality of candidate legacy USB type A charging protocols to the USB element to determine a best protocol among the candidate legacy USB type A charging protocols to be used by the USB element.