LDO regulator with improved load transient performance for internal power supply
First Claim
1. A circuit, comprising:
- a voltage regulator circuit with a feedback regulation loop and a drive transistor configured to supply an output current to a regulated output node; and
a transient recovery circuit, comprising;
a first transistor having a first source-drain path coupled to a control terminal of the drive transistor;
a first control circuit configured to deactuate the first transistor when the voltage regulator circuit is operating in a quiescent state and actuate the first transistor in response to detection of a transient voltage drop at the regulated output node to source a first current to the control terminal of the drive transistor in addition to a regulation control current applied by the feedback regulation loop;
a second transistor having a second source-drain path coupled to the regulated output node; and
a second control circuit configured to bias operation of the second transistor to sink a first non-zero magnitude current from the regulated output node when the voltage regulator circuit is operating in the quiescent state and to bias operation of the second transistor to sink a second non-zero magnitude current that is greater than the first non-zero magnitude current from the regulated output node in response to detection of a transient voltage increase at the regulated output node.
1 Assignment
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Accused Products
Abstract
A voltage regulator includes a feedback regulation loop and a drive transistor configured to source current to a regulated output. A transient recovery circuit is coupled to the voltage regulator circuit and includes a first transistor coupled to source current into a control terminal of the drive transistor, wherein the source current is in addition to current sourced in response to operation of the feedback regulation loop. The first transistor is selectively actuated in response to a drop in voltage at the regulated output. The transient recovery circuit further includes a second transistor coupled to sink current from the regulated output. The sink current has a first non-zero magnitude in the quiescent operating mode of the regulator circuit. In response to an increase in voltage at the regulated output, the operation of the second transistor is modified to increase the sink current to a second, greater, non-zero magnitude.
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Citations
35 Claims
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1. A circuit, comprising:
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a voltage regulator circuit with a feedback regulation loop and a drive transistor configured to supply an output current to a regulated output node; and a transient recovery circuit, comprising; a first transistor having a first source-drain path coupled to a control terminal of the drive transistor; a first control circuit configured to deactuate the first transistor when the voltage regulator circuit is operating in a quiescent state and actuate the first transistor in response to detection of a transient voltage drop at the regulated output node to source a first current to the control terminal of the drive transistor in addition to a regulation control current applied by the feedback regulation loop; a second transistor having a second source-drain path coupled to the regulated output node; and a second control circuit configured to bias operation of the second transistor to sink a first non-zero magnitude current from the regulated output node when the voltage regulator circuit is operating in the quiescent state and to bias operation of the second transistor to sink a second non-zero magnitude current that is greater than the first non-zero magnitude current from the regulated output node in response to detection of a transient voltage increase at the regulated output node. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method, comprising:
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operating a drive transistor of a voltage regulator circuit to source current to a regulated output node using a feedback regulation loop; in response to a sensed transient voltage decrease at the regulated output node, sourcing current into a control terminal of the drive transistor in addition to current sourced to the control terminal by operation of the feedback regulation loop; sinking a first non-zero magnitude current from the regulated output node when the voltage regulator circuit is operating in a quiescent state; and in response to a sensed transient voltage increase at the regulated output node, sinking a second non-zero magnitude current that is greater than the first non-zero magnitude current from the regulated output node. - View Dependent Claims (13, 14)
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15. A circuit, comprising:
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a voltage regulator circuit with a feedback regulation loop and a drive transistor configured to supply an output current to a regulated output node; a first transistor having a first source-drain path coupled to the regulated output node and configured to source a first current to said regulated output node when the voltage regulator circuit is operating in a quiescent state; a second transistor having a second source-drain path coupled to the regulated output node; and a control circuit configured to bias operation of the second transistor to sink a first non-zero magnitude current from the regulated output node when the voltage regulator circuit is operating in the quiescent state and to bias operation of the second transistor to sink a second, greater, non-zero magnitude current from the regulated output node in response to detection of a transient voltage increase at the regulated output node; wherein the first non-zero magnitude current sunk from the regulated output node offsets the first current sourced to the regulated output node.
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16. A circuit, comprising:
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a voltage regulator circuit with a feedback regulation loop and a drive transistor configured to supply an output current to a regulated output node; a first transistor having a first source-drain path coupled to the regulated output node and configured to source a first current to said regulated output node when the voltage regulator circuit is operating in a quiescent state; a second transistor having a second source-drain path coupled to the regulated output node; a control circuit configured to bias operation of the second transistor to sink a first non-zero magnitude current from the regulated output node when the voltage regulator circuit is operating in the quiescent state and to bias operation of the second transistor to sink a second, greater, non-zero magnitude current from the regulated output node in response to detection of a transient voltage increase at the regulated output node; and a third transistor having a third source-drain path coupled to a control terminal of the drive transistor, wherein said first transistor is configured to bias said third transistor in an off state when the voltage regulator circuit is operating in a quiescent state. - View Dependent Claims (17)
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18. A circuit, comprising:
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a voltage regulator circuit with a feedback regulation loop and a drive transistor configured to supply an output current to an output node; and a transient recovery circuit, comprising; a first transistor having a first source-drain path coupled to a control terminal of the drive transistor; a first control circuit configured to deactuate the first transistor when a voltage at the output node is regulated to a regulated voltage level set by the feedback regulation loop and actuate the first transistor to source a first current to the control terminal of the drive transistor in response to the voltage at the output node experiencing a transient voltage drop; a second transistor having a second source-drain path coupled to the regulated output node; and a second control circuit configured to bias operation of the second transistor to sink a first non-zero magnitude current from the regulated output node when the voltage at the output node is regulated to the regulated voltage level set by the feedback regulation loop and to bias operation of the second transistor to sink a second non-zero magnitude current greater than the first non-zero magnitude current from the regulated output node in response to the voltage at the output node experiencing a transient voltage increase. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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29. A circuit, comprising:
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a voltage regulator circuit with a feedback regulation loop and a drive transistor configured to supply an output current to an output node to generate a voltage at the output node that is regulated to a regulated voltage level set by the feedback regulation loop; a first transistor having a first source-drain path coupled to the regulated output node and configured to source a first current to said regulated output node; a second transistor having a second source-drain path coupled to the regulated output node; and a control circuit configured to bias operation of the second transistor to sink a first non-zero magnitude current from the regulated output node when the voltage at the output node is regulated to the regulated voltage level set by the feedback regulation loop and to bias operation of the second transistor to sink a second non-zero magnitude current greater than the first non-zero magnitude current from the regulated output node in response to the voltage at the output node experiencing a transient voltage increase. - View Dependent Claims (30, 31, 32)
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33. A method, comprising:
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operating a drive transistor of a voltage regulator circuit to source current to a regulated output node using a feedback regulation loop to generate a regulated voltage at the regulated output node during a regulating mode of operation; in response to a sensed transient voltage decrease at the regulated output node, sourcing current into a control terminal of the drive transistor in addition to current sourced during a transient mode of operation to the control terminal by operation of the feedback regulation loop; sinking a first non-zero magnitude current from the regulated output node when the voltage regulator circuit is operating in the regulating mode of operation; and in response to a sensed transient voltage increase at the regulated output node, sinking a second, greater, non-zero magnitude current from the regulated output node during the transient mode of operation. - View Dependent Claims (34, 35)
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Specification