Power supply system, associated current ripple suppression circuit and method
AssigneeChengdu Monolithic Power Systems Co., Ltd.
InventorsNaixing Kuang, Jiaqi Yu, Bo Yu
Life of this patent
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Abstract
A power supply system has a current source configured to provide an output current, a load supplied by the current source, and a current ripple suppression circuit. The current ripple suppression circuit has a first end and a second end, wherein the first end of the current ripple suppression circuit is coupled to the load, and the second end of the current ripple suppression circuit is coupled to a reference ground; wherein the current ripple suppression circuit is configured to suppress the current ripple in the output current and adaptively adjust the output current of the current source at a predetermined current level.
Claims20
A power supply system, comprising:
- a current source having an output, wherein the output of the current source is configured to provide an output current;
- a load having a first end and a second end, wherein the first end of the load is coupled to the output of the current source, and wherein the current source is configured to supply the load with the output current;
- and
- a current ripple suppression circuit having a first end and a second end, wherein the first end of the current ripple suppression circuit is coupled to the second end of the load, and the second end of the current ripple suppression circuit is coupled to a reference ground;
- wherein the current ripple suppression circuit is configured to suppress the current ripple in the output current and adaptively adjust the output current of the current source at a predetermined current level by comparing the voltage at the first end of the current ripple suppression circuit with a reference voltage, and wherein when the voltage at the first end of the current ripple suppression circuit is higher than the reference voltage, the current ripple suppression circuit is configured to increase a current flowing through the load, and when the voltage at the first end of the current ripple suppression circuit is lower than the reference voltage, the current ripple suppression circuit is configured to decrease the current flowing through the load.
A method of suppressing current ripple in a current source, the method comprising:
- coupling a linear device to the current source in series;
- obtaining an error amplifying signal by amplifying the difference between a voltage at a first end of the linear device and a reference voltage;
- converting the error amplifying signal into an interim voltage, wherein the interim voltage is lower than the reference voltage;
- coupling the interim voltage into a first input of an amplifier;
- coupling a signal indicating a current flowing through the linear device into a second input of the amplifier;
- and
- regulating the conduction resistance of the linear device by the output of the amplifier;
- wherein
- when the voltage at the first end of the linear device is higher than the reference voltage, increasing the current flowing through the linear device, and when the voltage at the first end of the linear device is lower than the reference voltage, decreasing the current flowing through the linear device.
A current ripple suppression circuit for suppressing current ripple in a current source, the current ripple suppression circuit having a first end and second end, the current ripple suppression circuit comprising:
- a transistor having a first end, a second end and a control end, wherein the first end of the transistor is coupled to the first end of the current ripple suppression circuit, and the second end of the transistor is coupled to the second end of the current ripple suppression circuit;
- and
- a control circuit having a first input, a second input and an output, wherein the first input of the control circuit is coupled to the first end of the transistor configured to receive a terminal voltage at the first end of the transistor, the second input of the control circuit is coupled to the second end of the transistor configured to receive a signal indicating the current flowing through the transistor, and the output of the control circuit is coupled to the control end of the transistor, and wherein the control circuit is configured to adjust the resistance between the first end of the transistor and the second end of the transistor by comparing the terminal voltage with a reference voltage, when the terminal voltage is higher than the reference voltage, the current ripple suppression circuit is configured to increase the current flowing through the transistor, and when the terminal voltage is lower than the reference voltage, the current ripple suppression circuit is configured to decrease the current flowing through the transistor.
The current ripple suppression circuit of 16, wherein the error amplifying circuit comprises:
- an error amplifier having an inverting input, a non-inverting input and an output, wherein the inverting input of the error amplifier is coupled to the first end of the transistor, and the non-inverting input of the error amplifier is coupled to the reference voltage;
- and
- a capacitor having a first end and a second end, wherein the first end of the capacitor is configured to provide the error amplifying signal, and the second end of the capacitor is coupled to the second end of the current ripple suppression circuit.
Dependencies are inferred from the claim text.