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 configured to source a first current to a control terminal of the drive transistor, wherein said first current is supplied in addition to a regulation control current applied to the control terminal of the drive transistor in response to operation of the feedback regulation loop;
a first control circuit configured to selectively actuate the first transistor in response to a drop in voltage at the regulated output node;
a second transistor configured to sink a second current from the regulated output node; and
a second control circuit configured to control operation of said second transistor to increase a magnitude of the second current, from a first non-zero magnitude to a second, greater, non-zero magnitude, in response to an increase in voltage at the regulated output node.
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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
26 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 configured to source a first current to a control terminal of the drive transistor, wherein said first current is supplied in addition to a regulation control current applied to the control terminal of the drive transistor in response to operation of the feedback regulation loop; a first control circuit configured to selectively actuate the first transistor in response to a drop in voltage at the regulated output node; a second transistor configured to sink a second current from the regulated output node; and a second control circuit configured to control operation of said second transistor to increase a magnitude of the second current, from a first non-zero magnitude to a second, greater, non-zero magnitude, in response to an increase in voltage at the regulated output node. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. 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; sensing transient voltage change at the regulated output node; and responding to the sensed transient voltage change by; selectively sourcing current into a control terminal of the drive transistor in response to a sensed drop in voltage at the regulated output node, said selectively sourced current being in addition to current sourced to the control terminal in response to operation of the feedback regulation loop; and increasing a magnitude of sinking current, from a first non-zero magnitude to a second, greater, non-zero magnitude, which is sunk from the regulated output node in response to a sensed increase in voltage at the regulated output node. - View Dependent Claims (16, 17, 18)
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19. 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 transistor configured to be selectively actuated in response to a change in voltage at the regulated output node, said selectively actuated transistor configured to apply current to a control terminal of the drive transistor, said applied current being in addition to current applied to the control terminal of the drive transistor in response to operation of the feedback regulation loop. - View Dependent Claims (20, 21, 22)
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23. 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 transistor coupled to apply current to the regulated output node, said transistor configured to increase a magnitude of the applied current, from a first non-zero magnitude to a second, greater, non-zero magnitude, in response to a change in voltage at the regulated output node. - View Dependent Claims (24, 25, 26)
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Specification