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US 9,069,369 B1Granted
Voltage regulator and a method to operate the voltage regulator
AssigneeAltera Corporation
InventorsPing-Chen Liu, Justin Jon Philpott, Arvind Sherigar
Life of this patent
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Abstract
A voltage regulator is disclosed. The voltage regulator includes an operational amplifier (op-amp) and a voltage trim circuit. The op-amp is operable to receive a reference voltage at a first terminal. The op-amp also includes an output terminal. The voltage trim circuit is coupled between the output terminal and a second terminal of the op-amp. The voltage trim circuit is operable to modify an output voltage to be substantially equivalent with the reference voltage. The modification is performed by selecting an electrical current propagating pathway. An IC and a method to operate the voltage regulator is also disclosed.
Claims21
A voltage regulator comprising:
- an operational amplifier receiving a reference voltage on a first input terminal, the operational amplifier having an output terminal;
- and
- a voltage trim circuit coupled to the output terminal and a second input terminal of the operational amplifier, the voltage trim circuit having a resistor, wherein:
- a first terminal of the resistor is coupled to the output terminal and a second terminal of the resistor is coupled to the second input terminal of the operational amplifier,
- when a first pathway comprising the resistor is selected, a first electrical current passes through the resistor, wherein an initial output voltage of the output terminal is increased by a first predetermined voltage generated across the resistor to yield a first output voltage, and the second terminal of the resistor delivers the first output voltage to the second input terminal of the operational amplifier, and
- when a second pathway comprising the resistor is selected, a second electrical current passes through the resistor, wherein the initial output voltage is decreased by a second predetermined voltage generated across the resistor to yield a second output voltage, and the second terminal of the resistor delivers the second output voltage to the second input terminal of the operational amplifier.
3 more elements
A voltage trim circuit comprising:
- a resistor, a first terminal of the resistor receiving an initial output voltage of an operational amplifier, a second terminal of the resistor delivering either a first output voltage or a second output voltage to a negative input of the operational amplifier;
- a first current source coupled to the first terminal of the resistor;
- a first current sink coupled to the second terminal of the resistor, wherein when a first pathway comprising the resistor is selected, a first programmable electrical current generated from the first current source propagates through the resistor to ground via the first current sink, the initial output voltage is increased by a first predetermined voltage generated across the resistor to yield the first output voltage, and the second terminal of the resistor delivers the first output voltage to the negative input of the operational amplifier;
- a second current source coupled to the second terminal of the resistor;
- and
- a second current sink coupled to the first terminal of the resistor, wherein when a second pathway comprising the resistor is selected, a second programmable electrical current generated from the second current source propagates through the resistor to ground via the second current sink, the initial output voltage is decreased by a second predetermined voltage generated across the resistor to yield the second output voltage, and the second terminal of the resistor delivers the second output voltage to the negative input of the operational amplifier.
3 more elements
A method to operate a voltage regulator, comprising:
- receiving a reference voltage at a first input terminal of an operational amplifier (op-amp);
- determining whether an initial output voltage of the op-amp requires a voltage level modification;
- in response to a determination that the initial output voltage of the op-amp requires a voltage level modification, selecting a direction of an electrical current to propagate within a voltage trim circuit to enable trimming of the initial output voltage of the op-amp, the voltage trim circuit having a resistor;
- when a first pathway comprising the resistor is selected, increasing the initial output voltage by a first predetermined voltage generated across the resistor to yield a first output voltage, wherein a first electrical current passes through the resistor, a first terminal of the resistor receives the initial output voltage of the op-amp, and a negative input terminal of the op-amp receives the first output voltage of a second terminal of the resistors;
- when a second pathway comprising the resistor is selected, decreasing the initial output voltage by a second predetermined voltage generated across the resistor to yield a second output voltage, wherein a second electrical current passes through the resistor, and the negative input terminal of the op-amp receives the second output voltage of the second terminal of the resistor;
- and
- outputting a final output voltage of the op-amp through an output terminal of the op-amp.
4 more elements
Dependencies are inferred from the claim text.