发明名称 |
Electronic Device Power Protection Circuitry |
摘要 |
A host electronic device may be coupled to an accessory electronic device. During normal operation, the host device may supply the accessory device with power over a power supply line. Back-powering events in which the accessory device delivers power to the host device may be prevented by interposing a protection transistor in the power supply line. A current mirror may be formed using the protection transistor and an additional transistor that produces a sense current proportional to the amount of current that is flowing through the power supply line. A current-to-voltage amplifier may produce a sense voltage that is proportional to the sense current. A bias circuit may be used to bias the sense current through the current mirror. A control circuit may compare the sense voltage to one or more reference voltages and turn off the protection transistor when appropriate to prevent back-powering of the host device. |
申请公布号 |
US2016320788(A1) |
申请公布日期 |
2016.11.03 |
申请号 |
US201615143321 |
申请日期 |
2016.04.29 |
申请人 |
Apple Inc. |
发明人 |
Paul Rajarshi;Perez Yehonatan;Hrinya Stephen J.;Shoykhet Eugene L. |
分类号 |
G05F3/02;H02H9/02;H04W88/02 |
主分类号 |
G05F3/02 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
Cupertino CA US |