Method of optimum current blanking time implementation in current sense circuit
First Claim
1. A current sensing circuit comprising:
- a power switch coupled to receive a current from a switching input, the power switch being controlled by a gate signal, wherein a turn on of the power switch causes the current to have an initial transient spike;
a buffer having a buffer input and a buffer output, the buffer input being coupled to receive the gate signal and provide a buffered gate signal at the buffer output, wherein the buffer output is disabled during the initial transient spike;
a sense switch coupled to receive a portion of the current from the switching input, the sense switch being turned on by the buffered gate signal after the initial transient spike; and
a sense resistor coupled to receive the portion of the current from the sense switch.
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Accused Products
Abstract
In a method and system for sensing current in a switching regulator (SWR) operating in a current mode, a power switch is coupled to receive the current from a switching element, the power switch being controlled by a gate signal. An inrush of the current causes an initial transient spike (ITS). A buffer having a buffer input and a buffer output is coupled to receive the gate signal and provide a buffered gate signal. The buffer output is disabled during the ITS. A sense switch (SW) is coupled to receive a portion of the current from the switching element, the SW being turned on by the buffered gate signal after the initial transient spike. A sense resistor (SR) is coupled to receive the portion of the current from the SW. An amplifier converts the portion of the current through the SR to a voltage signal for controlling the SWR.
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Citations
20 Claims
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1. A current sensing circuit comprising:
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a power switch coupled to receive a current from a switching input, the power switch being controlled by a gate signal, wherein a turn on of the power switch causes the current to have an initial transient spike; a buffer having a buffer input and a buffer output, the buffer input being coupled to receive the gate signal and provide a buffered gate signal at the buffer output, wherein the buffer output is disabled during the initial transient spike; a sense switch coupled to receive a portion of the current from the switching input, the sense switch being turned on by the buffered gate signal after the initial transient spike; and a sense resistor coupled to receive the portion of the current from the sense switch. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method of sensing a current flowing through a power switch of a switching regulator, the method comprising:
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turning on the power switch to enable the current to flow, the turning on causing an initial transient spike in the current; controlling a sense switch to turn on after the occurrence of the initial transient spike, the sense switch being operable to sense a portion of the current. - View Dependent Claims (11, 12, 13, 14, 15, 16)
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17. An electronic system comprising:
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a load; and a switching regulator operable to provide power to the load, the switching regulator including; an energy storage element coupled to receive a voltage input at an input terminal; a current sensing circuit including; a power switch coupled to receive a current from the energy storage element, the power switch being controlled by a gate signal, wherein an inrush of the current causes an initial transient spike; a buffer having a buffer input and a buffer output, the buffer input being coupled to receive the gate signal and provide a buffered gate signal at the buffer output, wherein the buffer output is disabled during the initial transient spike; a sense switch coupled to receive a portion of the current from the energy storage element, the sense switch being turned on by the buffered gate signal after the initial transient spike; a sense resistor coupled to receive the portion of the current from the sense switch; an amplifier operable to convert the portion of the current through the sense resistor to a feedback signal; a controller coupled to receive the feedback signal derived as a function of the current flowing through the energy storage element, wherein the controller provides the gate signal in response to the feedback signal. - View Dependent Claims (18, 19, 20)
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Specification