Degradation detection device and degradation detection method
AssigneesKabushiki Kaisha Toshiba, Toshiba Electronic Devices & Storage Corporation
InventorHideaki Majima
Life of this patent
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Abstract
According to one embodiment, a degradation detection device includes a driving circuit that supplies a driving signal that controls on/off of an output transistor to the output transistor and an output circuit that compares a value of integral of an output current that is output by the output transistor in an off-state thereof over a predetermined period of time with a predetermined threshold when the output transistor is turned from an on-state thereof to an off-state thereof and outputs a signal that indicates a degradation state of the output transistor depending on a result of such comparison.
Claims18
A degradation detection device, comprising:
- an output transistor with a source and a drain connected between a power source supply terminal and an output terminal;
- a driving circuit that supplies a driving signal that controls on/off of the output transistor to the output transistor;
- and
- an output circuit configured to:
- integrate an output current that is discharged from a source side of the output transistor according to a drain charge over a predetermined period of time when the output transistor is shifted from an on-state thereof to an off-state thereof;
- compare a value of an integral of the output current with a predetermined threshold;
- and
- output a signal that indicates that degradation of the output transistor is absent in response to the value of the integral being larger than the predetermined threshold and that the degradation of the output transistor is present in response to the value of the integral being smaller than the predetermined threshold.
A degradation detection method, comprising:
- shifting an output transistor with a source and a drain connected between a power source supply terminal and an output terminal from an on-state thereof to an off-state thereof;
- integrating an output current that is discharged from a source side of the output transistor according to a drain charge over a predetermined period of time when the output transistor is shifted to the off-state thereof to obtain a value of an integral of the output current;
- comparing the value of the integral with a predetermined threshold;
- and
- outputting a signal that indicates that degradation of the output transistor is absent in response to the value of the integral being larger than the predetermined threshold and that the degradation of the output transistor is present in response to the value of the integral being smaller than the predetermined threshold.
A degradation detection device, comprising:
- a first output transistor that has a main current path with one end that is connected to a power source supply terminal;
- a second output transistor that has a main current path with one end that is connected to the other end of the main current path of the first output transistor and the other end that is connected to an output terminal;
- a third output transistor that has a main current path with one end that is connected to the other end of the main current path of the second output transistor;
- a fourth output transistor with one end that is connected to the other end of the main current path of the third output transistor and the other end that is grounded;
- a driving circuit that supplies a driving signal that controls on/off of the first to fourth output transistors to the first to fourth output transistors;
- and
- a determination circuit that compares a value of an integral of an output current that is output by the first output transistor in an off-state thereof over a predetermined period of time with a predetermined threshold when the first output transistor is turned from an on-state thereof to an off-state thereof, and outputs a signal that indicates a degradation state of the first output transistor depending on a result of such comparison.
Dependencies are inferred from the claim text.