Power supply control circuit, power supply device, electronic apparatus, and power supply control method
AssigneeFujitsu Semiconductor Limited
InventorMorihito HASEGAWA
Life of this patent
Estimating the term…
Abstract
A control circuit includes a detection circuit configured to detect a load current flowing into a load, and a setting circuit configured to set switching operations on first and second switch circuits according to the load current. The setting circuit is configured to cause both the first switch circuit and the second switch circuit to be in an off state, when a power supply stop signal is input from an outside, if the load current is in a first range, and to cause the first switch circuit to perform an on-off operation on the basis of the output voltage while causing the second switch circuit to be in the off state, if the load current is higher than a first reference value that is an upper limit of the first range.
Claims18
A control circuit of a power supply which generates an output voltage from an input voltage by performing on-off control on a first switch circuit that is turned on to accumulate energy in an induction element and on a second switch circuit that is turned on to discharge the energy accumulated in the induction element to a load coupled to an output terminal, the control circuit comprising:
- a detection circuit configured to detect a load current flowing into the load;
- and
- a setting circuit configured to set switching operations on the first switch circuit and the second switch circuit according to the load current, wherein the setting circuit is configured
- to cause both the first switch circuit and the second switch circuit to be in an off state when a power supply stop signal is input from an outside, if the load current is in a first range, and,
- to cause the first switch circuit to perform an on-off operation on the basis of the output voltage while causing the second switch circuit to be in the off state, if the load current is higher than a first reference value that is an upper limit of the first range.
A control circuit of a power supply generating an output voltage from an input voltage by performing on-off control on a first switch circuit that is turned on for accumulating energy in an induction element and on a second switch circuit that is turned on for discharging the energy accumulated in the induction element to a load coupled to an output terminal, the control circuit comprising:
- a detection circuit configured to detect a load current flowing into the load;
- and
- a setting circuit configured to set switching operations on the first switch circuit and the second switch circuit according to the load current, wherein the setting circuit is configured
- to cause the first switch circuit and the second switch circuit to be in an off state if the load current at a time when a power supply stop signal is input from an outside is in a first range, and,
- to cause the first switch circuit to perform an operation including a time period for an on-off operation and a time period for setting an off state on the basis of the output voltage while causing the second switch circuit to perform an on-off operation, if the load current is lower than a second reference value that is a lower limit of the first range.
A power supply device comprising:
- a first switch circuit configured to be turned on for accumulating energy in an induction element;
- a second switch circuit configured to be turned on for discharging the energy accumulated in the induction element to a load coupled to an output terminal;
- and
- a control circuit configured to perform on-off control on the first switch circuit and the second switch circuit, wherein the control circuit includes:
- a detection circuit configured to detect a load current flowing into the load;
- and
- a setting circuit configured to set switching operations on the first switch circuit and the second switch circuit according to the load current, wherein when a power supply stop signal is input from an outside, if the load current is in a first range, the setting circuit causes both the first switch circuit and the second switch circuit to be in an off state, and, if the load current is higher than a first reference value that is an upper limit of the first range, the setting circuit performs an on-off operation on the first switch circuit on the basis of an output voltage generated at the output terminal and causes the second switch circuit to be in the off state.
An electronic apparatus comprising:
- a power supply including
- a first switch circuit configured to be turned on to accumulate energy in an induction element,
- a second switch circuit configured to be turned on to discharge the energy accumulated in the induction element to a load coupled to an output terminal, and
- a control circuit configured to perform on-off control on the first switch circuit and the second switch circuit;
- and
- an internal circuit to which an output voltage of the power supply is supplied,
- wherein the control circuit includes:
- a detection circuit configured to detect a load current flowing into the load;
- and
- a setting circuit configured to set switching operations on the first switch circuit and the second switch circuit according to the load current, wherein when a power supply stop signal is input from an outside, if the load current is in a first range, the setting circuit causes the first switch circuit and the second switch circuit to be in an off state, and, if the load current is higher than a first reference value that is an upper limit of the first range, the setting circuit performs an on-off operation on the first switch circuit on the basis of the output voltage and causes the second switch circuit to be in the off state.
A control method of a power supply which generates an output voltage from an input voltage by performing on-off control on a first switch circuit that is turned on for accumulating energy in an induction element and on a second switch circuit that is turned on for discharging the energy accumulated in the induction element to a load coupled to an output terminal, the method comprising:
- detecting a load current flowing into the load when a power supply stop signal is input from an outside;
- if the load current is in a first range, causing both the first switch circuit and the second switch circuit to be in an off state;
- and
- if the load current is higher than a first reference value that is an upper limit of the first range, performing an on-off operation on the first switch circuit on the basis of the output voltage and causing the second switch circuit to be in the off state.
A power supply device comprising:
- a first switch circuit configured to be turned on for accumulating energy in an induction element;
- a second switch circuit configured to be turned on for discharging the energy accumulated in the induction element to a load connected to an output terminal;
- and
- a control circuit configured to perform on-off control on the first switch circuit and the second switch circuit, wherein the control circuit includes
- a detection circuit configured to detect a load current flowing into the load, and
- a setting circuit configured to set switching operations on the first switch circuit and the second switch circuit according to the load current, wherein when a power supply stop signal is input, if the load current is in a first range, the setting circuit causes both the first switch circuit and the second switch circuit to be in an off state, and, if the load current is higher than a first reference value that is an upper limit of the first range, the setting circuit performs an on-off operation on the first switch circuit on the basis of an output voltage generated at the output terminal and causes the second switch circuit to be in the off state.
Dependencies are inferred from the claim text.