Switching circuit and power supply device
A switching circuit includes a switching transistor, a metal unit, and a branch. The metal unit is provided at the switching transistor, and the branch is electrically connected between a ground and at least one of the switching transistor or between the metal unit. The branch includes a capacitor, and the capacitor is configured to discharge radiated interference.
1. A switching circuit, comprising:
at least two switching transistors;
a metal unit comprising metal sub-units in one-to-one correspondence with the switching transistors, wherein each of the metal sub-units is provided at one of the switching transistors; and
a branch comprising a capacitor, the capacitor being configured to discharge radiated interference;
wherein:
the metal unit is electrically connected to a ground through the switching transistors and the branch in sequence; and
the branch comprises sub-legs in one-to-one correspondence with the metal sub-units, wherein each of the sub-legs is electrically connected between one of the metal sub-units and the ground.
2. The switching circuit according to claim 1 , wherein the branch further comprises a resistor connected in series with the capacitor.
3. The switching circuit according to claim 1 , wherein:
the capacitor is a first capacitor; and
the branch further comprises a second capacitor connected in series with the first capacitor.
4. The switching circuit according to claim 1 , wherein:
the switching transistors form at least two bridge arms connected in parallel, wherein each of the bridge arms comprises two of the switching transistors connected in series; and
the sub-legs of the branch are in one-to-one correspondence with the bridge arms, wherein each of the sub-legs is electrically connected between one of the bridge arms and the ground.
5. The switching circuit according to claim 1 , further comprising:
a spacer provided between at least one of the switching transistors and the metal unit.
6. The switching circuit according to claim 1 , wherein a capacitance of the capacitor ranges from 1 nF to 10 nF, wherein nF represents the unit nanofarad of capacitance.
7. The switching circuit according to claim 1 , further comprising:
a filter branch connected to an alternating-current power supply and the switching transistors, wherein the filter branch is configured to filter out differential-mode interference and common-mode interference from the alternating-current power supply.
8. A power supply device, comprising:
the switching circuit according to claim 1 .
9. The power supply device according to claim 8 , wherein the power supply device is a switching power supply or a charging pile.
10. A switching circuit, comprising:
at least two switching transistors;
a metal unit comprising metal sub-units in one-to-one correspondence with the at least two switching transistors, wherein each of the metal sub-units is provided at one of the at least two switching transistors; and
a branch comprising sub-legs in one-to-one correspondence with the metal sub-units, wherein each of the sub-legs is electrically connected between a ground and one of the metal sub-units;
wherein the branch comprises a capacitor, and the capacitor is configured to discharge radiated interference.
11. A switching circuit, comprising:
a plurality of switching transistors forming at least two bridge arms connected in parallel, wherein each of the bridge arms comprises two of the plurality of switching transistors connected in series;
a metal unit provided at one of the plurality of switching transistors; and
a branch comprising sub-legs in one-to-one correspondence with the bridge arms, wherein each of the sub-legs is electrically connected between a ground and one of the bridge arms;
wherein the branch comprises a capacitor, and the capacitor is configured to discharge radiated interference.