Voltage dependent die RC modeling for system level power distribution networks
AssigneeQUALCOMM Incorporated
InventorRyan Michael Coutts
Life of this patent
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Abstract
Techniques for determining the voltage-dependent capacitance of a circuit are described herein. In one embodiment, a method for determining voltage-dependent capacitance of a circuit comprises measuring a parameter of the circuit at each one of a plurality of voltages, and, for each voltage, determining a capacitance of the circuit at the voltage by fitting a resistor-capacitor (RC) model of the circuit to the measured parameter of the circuit at the voltage.
Claims23
A system, comprising:
- a circuit;
- and
- a power switch that connects the circuit to a power supply when the circuit is in an active state, and disconnects the circuit from the power supply when the circuit is in an inactive state, wherein the power switch has a variable resistance;
- and
- a switch control circuit that controls the resistance of the power switch as the circuit powers up from the inactive state to the active state by decreasing the resistance of the power switch at a first rate during a first time interval, and decreasing the resistance of the power switch at a second rate during a second time interval immediately following the first time interval, wherein the first rate is at least two times greater than the second rate, a boundary between the first and second time intervals corresponds to a time at which a voltage of the circuit reaches a threshold voltage of transistors in the circuit, and the switch control circuit comprises delay elements coupled in series, wherein the first rate and the second rate depend on delays of the delay elements.
A method for power gating in a system comprising a circuit and a power switch coupled between the circuit and a power supply, the method comprising:
- turning on the power switch when the circuit is to be awakened from an inactive state, wherein turning on the power switch comprises:
- decreasing a resistance of the power switch at a first rate during a first time interval;
- and
- decreasing the resistance of the power switch at a second rate during a second time interval immediately following the first time interval, wherein the first rate is at least two times greater than the second rate, and a boundary between the first and second time intervals corresponds to a time at which a voltage of the circuit reaches a threshold voltage of transistors in the circuit.
An apparatus for power gating in a system comprising a circuit and a power switch coupled between the circuit and a power supply, the apparatus comprising:
- means for turning on the power switch when the circuit is to be awakened from an inactive state, wherein the means for turning on the power switch comprises:
- means for decreasing a resistance of the power switch at a first rate during a first time interval;
- and
- means for decreasing the resistance of the power switch at a second rate during a second time interval immediately following the first time interval, wherein the first rate is at least two times greater than the second rate, and a boundary between the first and second time intervals corresponds to a time at which a voltage of the circuit reaches a threshold voltage of transistors in the circuit.
Dependencies are inferred from the claim text.