Circuit and method for detecting faulty diode
First Claim
1. A circuit for detecting a faulty diode comprising:
- a diode, having an anode connected to a voltage supply;
a first switch, having a first end connected to a cathode of the diode;
a testing current source, connected to a second end of the first switch;
an one-shot circuit, used to generated and transmit an output signal to a control end of the first switch; and
a comparator, having two ends respectively connected to a reference voltage input terminal for receiving a reference voltage and connected to the second end of the first switch;
a second switch, having a first end connected to the cathode of the diode; and
a control current source, connected to a second end of the second switch;
wherein when the one-shot circuit closes the first switch for a maintaining period to urge the comparator to compare the reference voltage with the voltage applied to the second end of the first switch, whereby a signal used to discriminate whether the diode is fail or not is generated and after the one-shot circuit closes the first switch for the maintaining period, the second switch is closed and the first switch is opened, whereby the control current source controls the diode.
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Accused Products
Abstract
A circuit for detecting faulty diode is disclosed, wherein the circuit for detecting faulty diode comprises a diode having an anode connecting to a voltage supply; a first switch having a first end connected to a cathode of the diode; a testing current source connected to the second end of the first switch; a one-shot circuit connected to a control end of the first switch, by which an output signal is generated and transmitted to the control end; and a comparator connected to a reference voltage input terminal for receiving a reference voltage and connected to the second end of the first switch. When the one-shot circuit closes the first switch for a maintaining period to urge the comparator comparing the reference voltage with the voltage applied to the second end of the first switch, whereby a signal used to discriminate whether the diode is fail or not is generated.
13 Citations
9 Claims
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1. A circuit for detecting a faulty diode comprising:
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a diode, having an anode connected to a voltage supply; a first switch, having a first end connected to a cathode of the diode; a testing current source, connected to a second end of the first switch; an one-shot circuit, used to generated and transmit an output signal to a control end of the first switch; and a comparator, having two ends respectively connected to a reference voltage input terminal for receiving a reference voltage and connected to the second end of the first switch; a second switch, having a first end connected to the cathode of the diode; and a control current source, connected to a second end of the second switch; wherein when the one-shot circuit closes the first switch for a maintaining period to urge the comparator to compare the reference voltage with the voltage applied to the second end of the first switch, whereby a signal used to discriminate whether the diode is fail or not is generated and after the one-shot circuit closes the first switch for the maintaining period, the second switch is closed and the first switch is opened, whereby the control current source controls the diode. - View Dependent Claims (2, 3, 4, 5)
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6. A method for detecting a faulty diode comprising:
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adopting a dominant operating mode to switch a control current source connected with a diode, so as to provide a control current flow through the diode; stopping the operating mode and adopting a detecting mode to switch a testing current source connected to the diode, so as to provide a test current flow through the diode, thereby identifying whether the diode is faulty or operational in accordance with a bias voltage of the diode; wherein after the detecting mode is held for a maintaining period, the detecting mode stops and the operating mode regains its dominance, and the maintaining period is less than 1 ms and is determined by a one-shot circuit. - View Dependent Claims (7, 8, 9)
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Specification