Adaptively controlling drive strength of multiplexed power from supply power rails in a power multiplexing system to a powered circuit
First Claim
1. A power multiplexing system, comprising:
- a power multiplexing circuit, comprising;
a first supply selection circuit coupled between a first supply power rail having a first voltage and an output power rail coupled to at least one powered circuit;
a second supply selection circuit coupled between a second supply power rail having a second voltage and the output power rail;
the first supply selection circuit configured to selectively drive the first voltage at the first supply power rail to the output power rail at a first drive strength based on a first drive strength indicator to variably adjust the output impedance of the first supply selection circuit; and
the second supply selection circuit configured to selectively drive the second voltage at the second supply power rail to the output power rail at a second drive strength based on a second drive strength indicator to variably adjust the output impedance of the second supply selection circuit;
wherein the first supply selection circuit further comprises a diode drop control circuit configured to establish a first diode drop connection between the first supply power rail and the output power rail, in response to a supply power rail switch signal indicating a supply power rail switch enable state to switch from supplying power to the output power rail via the first supply selection circuit to supplying power via the second supply selection circuit while the first diode drop connection is established; and
at least one control circuit configured to;
receive a first supply power rail selection indicator indicating a first supply power rail selection enable state in response to the second voltage being a voltage level less than a threshold voltage;
receive a second supply power rail selection indicator indicating a second supply power rail selection enable state in response to the second voltage being a voltage level equal to or higher than the threshold voltage;
monitor an output voltage of the output power rail; and
in response to the first supply power rail selection indicator indicating the first supply power rail selection enable state;
compare a voltage level of the output voltage at the output power rail to a first reference voltage level associated with the first supply selection circuit; and
selectively generate the first drive strength indicator based on the comparison of the voltage level of the output voltage at the output power rail to the first reference voltage level; and
in response to the second supply power rail selection indicator indicating the second supply power rail selection enable state;
compare the voltage level of the output voltage at the output power rail to a second reference voltage level associated with the second supply selection circuit; and
selectively generate the second drive strength indicator based on the comparison of the voltage level of the output voltage at the output power rail to the second reference voltage level.
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Accused Products
Abstract
Adaptively controlling drive strength of multiplexed power from supply power rails in a power multiplexing system to a powered circuit is disclosed. A power multiplexing circuit in the power multiplexing system includes a plurality of supply selection circuits (e.g., head switches) each coupled between a respective supply power rail and an output power rail coupled to the powered circuit. The power multiplexing circuit is configured to activate a selected supply selection circuit to switch coupling of an associated supply power rail to the output power rail to power the powered circuit. In one example, the supply selection circuits each include a plurality of power switch selection circuits coupled to an associated supply power rail. The power switch selection circuits are configured to be activated and deactivated by a control circuit to adjust drive strength of a multiplexed supply power rail based on operational conditions, which can account for performance variations.
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Citations
36 Claims
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1. A power multiplexing system, comprising:
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a power multiplexing circuit, comprising; a first supply selection circuit coupled between a first supply power rail having a first voltage and an output power rail coupled to at least one powered circuit; a second supply selection circuit coupled between a second supply power rail having a second voltage and the output power rail; the first supply selection circuit configured to selectively drive the first voltage at the first supply power rail to the output power rail at a first drive strength based on a first drive strength indicator to variably adjust the output impedance of the first supply selection circuit; and the second supply selection circuit configured to selectively drive the second voltage at the second supply power rail to the output power rail at a second drive strength based on a second drive strength indicator to variably adjust the output impedance of the second supply selection circuit; wherein the first supply selection circuit further comprises a diode drop control circuit configured to establish a first diode drop connection between the first supply power rail and the output power rail, in response to a supply power rail switch signal indicating a supply power rail switch enable state to switch from supplying power to the output power rail via the first supply selection circuit to supplying power via the second supply selection circuit while the first diode drop connection is established; and at least one control circuit configured to; receive a first supply power rail selection indicator indicating a first supply power rail selection enable state in response to the second voltage being a voltage level less than a threshold voltage; receive a second supply power rail selection indicator indicating a second supply power rail selection enable state in response to the second voltage being a voltage level equal to or higher than the threshold voltage; monitor an output voltage of the output power rail; and in response to the first supply power rail selection indicator indicating the first supply power rail selection enable state; compare a voltage level of the output voltage at the output power rail to a first reference voltage level associated with the first supply selection circuit; and selectively generate the first drive strength indicator based on the comparison of the voltage level of the output voltage at the output power rail to the first reference voltage level; and in response to the second supply power rail selection indicator indicating the second supply power rail selection enable state; compare the voltage level of the output voltage at the output power rail to a second reference voltage level associated with the second supply selection circuit; and selectively generate the second drive strength indicator based on the comparison of the voltage level of the output voltage at the output power rail to the second reference voltage level. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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24. A power multiplexing system, comprising:
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a first supply means for selectively driving a first voltage at a first supply power rail to an output power rail at a first drive strength based on a first drive strength indicator; a second supply means for selectively driving a second voltage at a second supply power rail to the output power rail at a second drive strength based on a second drive strength indicator; a means for establishing a first diode drop connection between the first supply power rail and the output power rail, in response to a supply power rail switch signal indicating a supply power rail switch enable state to switch from supplying power to the output power rail via the first supply means to supplying power via the second supply means while the first diode drop connection is established; a means for receiving a first supply power rail selection indicator indicating a first supply power rail selection enable state in response to the second voltage being a voltage level less than a threshold voltage; a means for receiving a second supply power rail selection indicator indicating a second supply power rail selection enable state in response to the second voltage being a voltage level equal to or higher than the threshold voltage; a means for monitoring an output voltage of the output power rail; a means for comparing a voltage level of the output voltage at the output power rail to a first reference voltage level associated with a first supply selection circuit, in response to the first supply power rail selection indicator indicating the first supply power rail selection enable state; a means for selectively generating the first drive strength indicator based on the means for comparing the voltage level of the output voltage at the output power rail to the first reference voltage level, in response to the first supply power rail selection indicator indicating the first supply power rail selection enable state; a means for comparing the voltage level of the output voltage at the output power rail to a second reference voltage level associated with a second supply selection circuit in response to the second supply power rail selection indicator indicating the second supply power rail selection enable state; and a means for selectively generating the second drive strength indicator based on the means for comparing the voltage level of the output voltage at the output power rail to the second reference voltage level in response to the second supply power rail selection indicator indicating the second supply power rail selection enable state.
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25. A method of adaptively controlling drive strength of multiplexed power from supply power rails in a power multiplexing circuit to a powered circuit, comprising:
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monitoring an output voltage of an output power rail; in response to a first supply power rail selection indicator indicating a first supply power rail selection enable state; comparing a voltage level of the output voltage at the output power rail to a first reference voltage level associated with a first supply selection circuit; selectively generating a first drive strength indicator based on the comparison of the voltage level of the output voltage at the output power rail to the first reference voltage level; and selectively driving a first voltage at a first supply power rail to the output power rail via a first supply selection circuit at a first drive strength based on the first drive strength indicator variably adjusting the output impedance of the first supply selection circuit; in response to a second supply power rail selection indicator indicating a second supply power rail selection enable state; comparing the voltage level of the output voltage at the output power rail to a second reference voltage level associated with a second supply selection circuit; selectively generating a second drive strength indicator based on the comparison of the voltage level of the output voltage at the output power rail to the second reference voltage level; and selectively driving a second voltage at a second supply power rail to the output power rail via a second supply selection circuit at a second drive strength based on the second drive strength indicator variably adjusting the output impedance of the second supply selection circuit; generating the first supply power rail selection indicator indicating the first supply power rail selection enable state in response to the second voltage being a voltage level less than a threshold voltage; generating the second supply power rail selection indicator indicating the second supply power rail selection enable state in response to the second voltage being a voltage level equal to or higher than the threshold voltage; and establishing a diode drop connection between the first supply power rail and the output power rail, in response to a supply power rail switch signal indicating a supply power rail switch enable state to switch from supplying power to the output power rail via the first supply selection circuit to supplying power via the second supply selecting circuit while the first diode drop connection is established. - View Dependent Claims (26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36)
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Specification