Switching regulator and comparator-based zero current detection method used by the switching regulator
First Claim
1. A switching regulator comprising:
- a switch configured to connect to a switching node and control an inductor current flowing through the switching node; and
a switch controller configured to control a turn-off time of the switch by detecting a change in a voltage of the switching node after the switch is turned off,wherein the switch controller comprises;
a comparator configured to compare a first voltage applied to a first input terminal connected to the switching node with a second voltage applied to a second input terminal connected to a first terminal of the switch and generate a comparison signal based on the comparison; and
a control logic configured to receive the comparison signal of the comparator and control an offset of the comparator to adjust the turn-off time of the switch based on the comparison signal, andwherein the control logic is configured to reduce the offset of the comparator if the comparison signal indicates that the turn-off time is before the inductor current becomes zero and increase the offset of the comparator if the comparison signal indicates that the turn-off time is after the inductor current becomes zero.
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Accused Products
Abstract
Provided are a switching regulator and a comparator-based zero current detection method. The switching regulator comprises: a switch configured to connect to a switching node and control an inductor current flowing through the switching node; and a switch controller configured to control a turn-off time of the switch by detecting a change in a voltage of the switching node after the switch is turned off, wherein the switch controller comprises: a comparator configured to compare a first voltage applied to a first input terminal connected to the switching node with a second voltage applied to a second input terminal connected to a first terminal of the switch; and a control logic configured to receive a comparison signal of the comparator and control an offset of the comparator to adjust the turn-off time of the switch.
21 Citations
20 Claims
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1. A switching regulator comprising:
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a switch configured to connect to a switching node and control an inductor current flowing through the switching node; and a switch controller configured to control a turn-off time of the switch by detecting a change in a voltage of the switching node after the switch is turned off, wherein the switch controller comprises; a comparator configured to compare a first voltage applied to a first input terminal connected to the switching node with a second voltage applied to a second input terminal connected to a first terminal of the switch and generate a comparison signal based on the comparison; and a control logic configured to receive the comparison signal of the comparator and control an offset of the comparator to adjust the turn-off time of the switch based on the comparison signal, and wherein the control logic is configured to reduce the offset of the comparator if the comparison signal indicates that the turn-off time is before the inductor current becomes zero and increase the offset of the comparator if the comparison signal indicates that the turn-off time is after the inductor current becomes zero. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A comparator-based zero current detection method used by a switching regulator, the method comprising:
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setting an offset of a comparator, which has a value from 1 to n, to m; and if it is required to increase the offset to (m+1); setting the offset of the comparator to (m+1) if the offset of the comparator was set to m by being increased from (m−
1), andmaintaining the offset of the comparator at m for P times and then setting the offset of the comparator to (m+1) if the offset of the comparator was set to m by being decreased from (m+1), wherein 1≦
m≦
n, m and n are natural numbers of digital bits, and P is a natural number. - View Dependent Claims (14, 15)
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16. A switch controller, comprising:
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a comparator comprising a first input terminal and a second input terminal, and configured to compare a first voltage applied to the first input terminal connected to an external switching node through which an inductor current flows with a second voltage applied to the second input terminal connected to a first terminal of an external switch; and a control logic configured to receive a comparison signal of the comparator based on the comparison of the first voltage and the second voltage, and control an offset of the comparator to adjust a turn-off time of the external switch, wherein the control logic is configured to reduce the offset of the comparator if the comparison signal indicates that the turn-off time is before the inductor current becomes zero and increase the offset of the comparator if the comparison signal indicates that the turn-off time is after the inductor current becomes zero. - View Dependent Claims (17, 18, 19, 20)
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Specification