Power supply device for vehicle
Provided is a vehicle power supply device that is capable of executing non-synchronous rectification control and synchronous rectification control while switching therebetween and can suppress, during switching from the non-synchronous rectification control to the synchronous rectification control, an output voltage value from significantly deviating from a target voltage value. If a determination unit determines, during the execution of the non-synchronous rectification control, that a current-increasing state arises, a driving unit performs switching to the synchronous rectification control in which a PWM signal with a duty cycle of a fixed value is supplied to a first switch unit, and then performs the synchronous rectification control in which a PWM signal with a duty cycle that is calculated by a feedback operation unit based on the target output voltage value and the detection result of the detecting unit is supplied to the first switch unit.
1. A vehicle power supply device comprising:
a voltage conversion unit configured to decrease an input voltage applied to a first conductive path and output the decreased voltage to a second conductive path;
a detecting unit configured to detect at least one of an output voltage value and an output current value that are output by the voltage conversion unit to the second conductive path; and
a signal generation circuit configured to generate a signal to be supplied to the voltage conversion unit,
the voltage conversion unit having:
a first switch unit and a second switch unit that are connected in series between the first conductive path and a reference conductive path that is kept at a predetermined reference potential lower than a potential of the first conductive path; and
an inductor that is provided between a connecting portion that connects the first switch unit and the second switch unit to each other and the second conductive path; and a diode unit that is connected, in parallel, to the second switch unit, a cathode of the diode unit being connected to the connecting portion side and an anode thereof being connected to the reference conductive path side,
the signal generation circuit having:
a feedback operation unit configured to perform a feedback operation for calculating, based on a target output voltage value of the voltage conversion unit and a detection result of the detecting unit, a duty cycle of a PWM signal that is to be supplied to the first switch unit;
a driving unit configured to supply, to the first switch unit, the PWM signal with the duty cycle calculated by the feedback operation unit, the driving unit being configured to execute synchronous rectification control for turning the second switch unit off and on in correspondence with turning the first switch unit on and off and non-synchronous rectification control for turning the first switch unit on and off while keeping the second switch unit turned off, while switching between the synchronous rectification control and the non-synchronous rectification control; and
a determination unit configured to determine whether or not the second conductive path is in a predetermined current-increasing state or a predetermined voltage-decreasing state,
wherein, if the determination unit determines, during the execution of the non-synchronous rectification control, that the second conductive path is in the predetermined current-increasing state or the predetermined voltage-decreasing state, the driving unit performs switching to the synchronous rectification control in which a PWM signal with a duty cycle of a predetermined set value is supplied to the first switch unit, and then performs the synchronous rectification control in which a PWM signal with a duty cycle that is calculated by the feedback operation unit based on the target output voltage value and the detection result of the detecting unit is supplied to the first switch unit.
2. The vehicle power supply device according to claim 1 , wherein the set value is a value based on the target output voltage value and a voltage value of the input voltage.
3. The vehicle power supply device according to claim 2 , wherein the set value is a value obtained by dividing the target output voltage value by the voltage value of the input voltage.
4. A vehicle power supply device comprising:
a voltage conversion unit configured to increase an input voltage applied to a first conductive path and output the increased voltage to a second conductive path;
a detecting unit configured to detect at least one of an output voltage value and an output current value that are output by the voltage conversion unit to the second conductive path; and
a signal generation circuit configured to generate a signal to be supplied to the voltage conversion unit,
the voltage conversion unit having:
an inductor and a first switch unit that are connected in series between the first conductive path and a reference conductive path that is kept at a predetermined reference potential lower than a potential of the first conductive path; a second switch unit that is provided between a connecting portion that connects the inductor and the first switch unit to each other and the second conductive path; and a diode unit that is connected, in parallel, to the second switch unit, an anode of the diode unit being connected to the connecting portion side and a cathode thereof being connected to the second conductive path side,
the signal generation circuit having:
a detecting unit configured to detect at least one of the output voltage value and the output current value that are output by the voltage conversion unit to the second conductive path;
a feedback operation unit configured to perform a feedback operation for calculating, based on a target output voltage value of the voltage conversion unit and a detection result of the detecting unit, a duty cycle of a PWM signal that is to be supplied to the first switch unit;
a driving unit configured to supply, to the first switch unit, the PWM signal with the duty cycle calculated by the feedback operation unit, the driving unit being configured to execute synchronous rectification control for turning the second switch unit off and on in correspondence with turning the first switch unit on and off and non-synchronous rectification control for turning the first switch unit on and off while keeping the second switch unit turned off, while switching between the synchronous rectification control and the non-synchronous rectification control; and
a determination unit configured to determine whether or not the second conductive path is in a predetermined current-increasing state or a predetermined voltage-decreasing state,
wherein, if the determination unit determines, during the execution of the non-synchronous rectification control, that the second conductive path is in the predetermined current-increasing state or the predetermined voltage-decreasing state, the driving unit performs switching to the synchronous rectification control in which a PWM signal with a duty cycle of a predetermined set value is supplied to the first switch unit, and then performs the synchronous rectification control in which a PWM signal with a duty cycle that is calculated by the feedback operation unit based on the target output voltage value and the detection result of the detecting unit is supplied to the first switch unit.
5. The vehicle power supply device according to claim 4 , wherein the set value is a value based on the target output voltage value and a voltage value of the input voltage.
6. The vehicle power supply device according to claim 5 , wherein the set value is a value obtained by dividing the difference between the target output voltage value and the voltage value of the input voltage by the target output voltage value.
7. The vehicle power supply device according to claim 1 ,
wherein the detecting unit is configured to detect the output current value,
the determination unit is configured to determine whether or not the output current value detected by the detecting unit is equal to or greater than a predetermined threshold value, and
if the determination unit determines, during the execution of the non-synchronous rectification control, that the output current value is equal to or greater than the predetermined threshold value, the driving unit performs switching to the synchronous rectification control in which a PWM signal with a duty cycle of the set value is supplied to the first switch unit, and then executes the synchronous rectification control in which a PWM signal with a duty cycle that is calculated by the feedback operation unit based on the target output voltage value and the detection result of the detecting unit is supplied to the first switch unit.
8. The vehicle power supply device according to claim 2 ,
wherein the detecting unit is configured to detect the output current value,
the determination unit is configured to determine whether or not the output current value detected by the detecting unit is equal to or greater than a predetermined threshold value, and
if the determination unit determines, during the execution of the non-synchronous rectification control, that the output current value is equal to or greater than the predetermined threshold value, the driving unit performs switching to the synchronous rectification control in which a PWM signal with a duty cycle of the set value is supplied to the first switch unit, and then executes the synchronous rectification control in which a PWM signal with a duty cycle that is calculated by the feedback operation unit based on the target output voltage value and the detection result of the detecting unit is supplied to the first switch unit.
9. The vehicle power supply device according to claim 3 ,
wherein the detecting unit is configured to detect the output current value,
the determination unit is configured to determine whether or not the output current value detected by the detecting unit is equal to or greater than a predetermined threshold value, and
if the determination unit determines, during the execution of the non-synchronous rectification control, that the output current value is equal to or greater than the predetermined threshold value, the driving unit performs switching to the synchronous rectification control in which a PWM signal with a duty cycle of the set value is supplied to the first switch unit, and then executes the synchronous rectification control in which a PWM signal with a duty cycle that is calculated by the feedback operation unit based on the target output voltage value and the detection result of the detecting unit is supplied to the first switch unit.
10. The vehicle power supply device according to claim 4 ,
wherein the detecting unit is configured to detect the output current value,
the determination unit is configured to determine whether or not the output current value detected by the detecting unit is equal to or greater than a predetermined threshold value, and
if the determination unit determines, during the execution of the non-synchronous rectification control, that the output current value is equal to or greater than the predetermined threshold value, the driving unit performs switching to the synchronous rectification control in which a PWM signal with a duty cycle of the set value is supplied to the first switch unit, and then executes the synchronous rectification control in which a PWM signal with a duty cycle that is calculated by the feedback operation unit based on the target output voltage value and the detection result of the detecting unit is supplied to the first switch unit.
11. The vehicle power supply device according to claim 5 ,
wherein the detecting unit is configured to detect the output current value,
the determination unit is configured to determine whether or not the output current value detected by the detecting unit is equal to or greater than a predetermined threshold value, and
if the determination unit determines, during the execution of the non-synchronous rectification control, that the output current value is equal to or greater than the predetermined threshold value, the driving unit performs switching to the synchronous rectification control in which a PWM signal with a duty cycle of the set value is supplied to the first switch unit, and then executes the synchronous rectification control in which a PWM signal with a duty cycle that is calculated by the feedback operation unit based on the target output voltage value and the detection result of the detecting unit is supplied to the first switch unit.
12. The vehicle power supply device according to claim 6 ,
wherein the detecting unit is configured to detect the output current value,
the determination unit is configured to determine whether or not the output current value detected by the detecting unit is equal to or greater than a predetermined threshold value, and
if the determination unit determines, during the execution of the non-synchronous rectification control, that the output current value is equal to or greater than the predetermined threshold value, the driving unit performs switching to the synchronous rectification control in which a PWM signal with a duty cycle of the set value is supplied to the first switch unit, and then executes the synchronous rectification control in which a PWM signal with a duty cycle that is calculated by the feedback operation unit based on the target output voltage value and the detection result of the detecting unit is supplied to the first switch unit.