Systems and methods for starting up analog circuits
First Claim
1. A startup circuit, comprising:
- an output node at an output voltage (VOUT);
an operational amplifier coupled to the output node;
a comparator comprising a first input configured to be coupled to a reference voltage (VREF), a second input, and an output;
a feedback loop coupling the output node to the second input; and
a turbo circuit coupled between the output and the output node and configured to be coupled to a supply voltage (VPWR), the turbo circuit is configured to increase VOUT, wherein;
the comparator is configured to compare VOUT and VREF, the turbo circuit is disabled when the VOUT at the output node is within a predetermined voltage of the VREF, the operational amplifier starts up when the VOUT at the output node is outside the predetermined voltage of the VREF, and the operational amplifier drives a load that is coupled to the output node.
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Accused Products
Abstract
Circuits, systems, and methods for starting up analog devices are provided. One circuit includes an output node at an output voltage (VOUT), a comparator configured to be coupled to a reference voltage (VREF), a feedback loop coupling the output node to the comparator, and a turbo circuit coupled between the output and the output node. The turbo circuit is configured to increase VOUT, the comparator is configured to compare VOUT and VREF, and the turbo circuit is enabled and disabled based on the comparison of VOUT and VREF. One system includes an analog device coupled to the above circuit. A method includes enabling the startup portion to start up the driver portion when VOUT is outside a predetermined voltage of VREF, disabling the startup portion when VOUT is within the predetermined voltage, and enabling the driver portion to drive the analog device subsequent to disabling the startup portion.
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Citations
19 Claims
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1. A startup circuit, comprising:
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an output node at an output voltage (VOUT); an operational amplifier coupled to the output node; a comparator comprising a first input configured to be coupled to a reference voltage (VREF), a second input, and an output; a feedback loop coupling the output node to the second input; and a turbo circuit coupled between the output and the output node and configured to be coupled to a supply voltage (VPWR), the turbo circuit is configured to increase VOUT, wherein; the comparator is configured to compare VOUT and VREF, the turbo circuit is disabled when the VOUT at the output node is within a predetermined voltage of the VREF, the operational amplifier starts up when the VOUT at the output node is outside the predetermined voltage of the VREF, and the operational amplifier drives a load that is coupled to the output node. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method of operating a startup circuit that includes a comparator and a turbo circuit, the method comprising:
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enabling the comparator by applying a reference voltage (VREF) to a first input of the comparator, wherein the comparator comprises an output, the first input, and a second input, wherein the second input is coupled via a feedback loop to an output node at an output voltage (VOUT); applying a supply voltage (VPWR) to the turbo circuit, wherein the turbo circuit is coupled between the output of the comparator and the output node; the turbo circuit increasing the VOUT based on a signal from the output of the comparator; starting up an operational amplifier when the VOUT at the output node is outside a predetermined voltage of the VREF; the comparator comparing the VOUT to the VREF; and disabling the turbo circuit when the VOUT is within the predetermined voltage of the VREF; wherein the operational amplifier is enabled to drive a load coupled to the output node. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19)
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Specification