Power supply device, control circuit and method for controlling power supply device
View Patent ↗A power supply device including a converter having a switch circuit to which an input voltage is supplied and a coil coupled between the switch circuit and an output end from which an output voltage is output; and a control circuit comparing between a feedback voltage and a reference voltage, and on/off controls the switch circuit according to a comparison result; wherein, the control circuit includes a current gradient detection circuit performs detection of a gradient of a coil current flows thorough the coil during an off period of the switch circuit and generates a slope voltage according to a result of the detection; and an adder circuit performs one of generating the feedback voltage by adding the slope voltage to a voltage according to the output voltage and generating the reference voltage by adding the slope voltage to a standard voltage that is set according to the output voltage.
1. A power supply device, comprising:
a converter unit that includes a switch circuit to which an input voltage is supplied and a coil that is coupled between the switch circuit and an output end from which an output voltage is output; and
a control circuit configured to perform a comparison between a feedback voltage and a reference voltage, and on/off controls of the switch circuit according to a result of the comparison;
wherein, the control circuit includes
a current gradient detection circuit configured to perform detection of a gradient of a coil current that flows thorough the coil during an off period of the switch circuit and generates a slope voltage according to a result of the detection; and
an adder circuit configured to generate the reference voltage by adding the slope voltage to a standard voltage.
2. The power supply device according to claim 1 , wherein, the converter unit includes a second switch that is coupled to a node between the switch circuit and the coil;
the control circuit is configured to control the switch circuit and the second switch circuit complementarily;
the coil current flows through the coil through the second switch circuit that is turned on; and
the current gradient detection circuit is configured to detect a gradient of the coil current based on a voltage of the node.
3. A power supply device, comprising:
a converter unit that includes a switch circuit to which an input voltage is supplied and a coil that is coupled between the switch circuit and an output end from which an output voltage is output, and
a control circuit configured to perform a comparison between a feedback voltage and a reference voltage, and on/off controls of the switch circuit according to a result of the comparison;
wherein, the control circuit includes a current gradient detection circuit configured to perform detection of a gradient of a coil current that flows thorough the coil during an off period of the switch circuit and generates a slope voltage according to a result of the detection; and an adder circuit configured to perform one of generating the feedback voltage by adding the slope voltage to a voltage according to the output voltage and generating the reference voltage by adding the slope voltage to a standard voltage that is set according to the output voltage,
wherein the converter unit includes: a serial circuit comprising a diode and a resistor that are coupled between a node of the switch circuit and the coil, and a power line;
the coil current flows through the coil during an off period of the switch circuit through the diode and the resistor; and
the current gradient detection circuit is configured to detect a gradient of the coil current based on the node voltage.
4. A power supply device, comprising:
a converter unit that includes a switch circuit to which an input voltage is supplied and a coil that is coupled between the switch circuit and an output end from which an output voltage is output; and
a control circuit configured perform a comparison between a feedback voltage and a reference voltage, and on/off controls of the switch circuit according to a result of the comparison;
wherein, the control circuit includes a current gradient detection circuit configured to perform detection of a gradient of a coil current that flows thorough the coil during an off period of the switch circuit and generates a slope voltage according to a result of the detection; and an adder circuit configured to perform one of generating the feedback voltage by adding the slope voltage to a voltage according to the output voltage and generating the reference voltage by adding the slope voltage to a standard voltage that is set according to the output voltage,
wherein the current gradient detection circuit includes:
an operational amplifier having a first input terminal coupled to a node between the switch circuit and the coil and a second input terminal coupled to the node through a switch, wherein the operational amplifier is configured to generate the slope voltage according to a differential voltage between the first input terminal and the second input terminal; and
a capacitor that is coupled to the second input terminal; and
wherein the switch is configured to turn on and off according to the on period and off period of the switch circuit.
5. A control method, comprising:
performing a comparison between a feedback voltage according to an output voltage and a reference voltage;
performing on/off controls of a switch circuit to which an input voltage is supplied based on a result of the comparison;
detecting a gradient of a coil current that flows through a coil coupled between the switch circuit and an output end from which the output voltage is output;
generating a slope voltage according to a result of the detecting; and
generating the reference voltage by adding the slope voltage to a standard voltage.
6. A power supply device, comprising:
a converter unit that includes a switch circuit to which an input voltage is supplied and a coil that is coupled between the switch circuit and an output end from which an output voltage is output; and
a control circuit configured to perform on/off controls of the switch circuit according to a result of the comparison;
wherein, the control circuit includes:
a current gradient detection circuit configured to perform detection of a gradient of a coil current that flows thorough the coil during an off period of the switch circuit and generates a slope voltage according to a result of the detection;
an adder circuit configured to receive the output voltage without going through an amplifier and perform generating a feedback voltage by adding the slope voltage to a voltage according to the output voltage; and
a comparator configured to perform a comparison between the feedback voltage and a reference voltage.
7. The power supply device according to claim 6 , wherein the current gradient detection circuit includes:
an operational amplifier having a first input terminal coupled to a node between the switch circuit and the coil and a second input terminal coupled to the node through a switch, wherein the operational amplifier is configured to generate the slope voltage according to a differential voltage between the first input terminal and the second input terminal; and
a capacitor that is coupled to the second input terminal; and
wherein the switch is configured to turn on and off according to the on period and off period of the switch circuit.