VBUS power switch
First Claim
1. A USB switch circuit configured to receive a supply voltage, to receive a USB bus voltage, and to provide an internal device voltage for operation of the USB switch circuit, the USB switch circuit comprising:
- a comparator configured to determine if the supply voltage is valid or invalid based on a comparison of the supply voltage with a reference voltage,the USB switch circuit being configured to;
provide the internal device voltage for operation of the USB switch circuit using the supply voltage when the supply voltage is valid and the USB bus voltage is greater than the supply voltage; and
provide the internal device voltage for operation of the USB switch circuit using the USB bus voltage when the supply voltage is invalid.
7 Assignments
0 Petitions
Accused Products
Abstract
This document discusses, among other things, an electronic circuit and method for defaulting to a valid battery supply to power an electronic device. In an example, an electronic circuit can be configured to receive information about the battery supply (e.g., an internal battery), such as the battery supply voltage (VBAT), and to determine if the battery supply is valid or invalid using the received information (e.g., comparing the VBAT to a threshold). If VBAT is valid, the electronic device can default to receiving power from the battery supply. If VBAT is invalid, the electronic device can receive power from another power supply, such as an external supply.
12 Citations
20 Claims
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1. A USB switch circuit configured to receive a supply voltage, to receive a USB bus voltage, and to provide an internal device voltage for operation of the USB switch circuit, the USB switch circuit comprising:
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a comparator configured to determine if the supply voltage is valid or invalid based on a comparison of the supply voltage with a reference voltage, the USB switch circuit being configured to; provide the internal device voltage for operation of the USB switch circuit using the supply voltage when the supply voltage is valid and the USB bus voltage is greater than the supply voltage; and provide the internal device voltage for operation of the USB switch circuit using the USB bus voltage when the supply voltage is invalid. - View Dependent Claims (2, 3, 4, 5, 6, 7, 9, 10)
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8. A USB switch circuit configured to receive a supply voltage, to receive a USB bus voltage, and to provide an internal device voltage for operation of the USB switch circuit, the USB switch circuit comprising:
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a comparator configured to compare the supply voltage with a reference voltage to determine if the supply voltage is valid or invalid; a switched power supply configured to receive the supply voltage and the USB bus voltage; and a break-before-make circuit configured to trigger the switched power supply to provide the internal device voltage using one of the supply voltage or the USB bus voltage using information from the comparator, the USB switch circuit being configured to control the switched power supply to; provide the internal device voltage for operation of the USB switch circuit using only the supply voltage when the supply voltage is valid, and provide the internal device voltage for operation of the USB switch circuit using only the USB bus voltage when the supply voltage is invalid. - View Dependent Claims (11, 12, 13, 14)
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15. A method, comprising:
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receiving a supply voltage at a first input of a USB switch circuit; receiving a USB bus voltage at a second input of the USB switch circuit; determining, using a comparator, if the supply voltage is valid or invalid based on a comparison of the supply voltage with a reference voltage; and using the USB switch circuit; providing an internal device voltage for operation of the USB switch circuit using the supply voltage when the supply voltage is valid; and providing the internal device voltage for operation of the USB switch circuit using the USB bus voltage when the supply voltage is invalid. - View Dependent Claims (16, 17, 18, 19, 20)
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Specification