Radio frequency switch circuit
A radio frequency switch circuit includes a series circuit. The series circuit includes a first series connection group and a second series connection group. The first series connection group includes a plurality of first transistors. The second series connection group includes a plurality of second transistors. Control terminals of the first transistors are all coupled to a first control node. Control terminals of the second transistors are all coupled to a second control node. When an electrostatic discharge event occurs, a voltage at the first control node is different from a voltage at the second control node. In a normal operation state, a switch state of the first series connection group and a switch state of the second series connection group are the same as each other.
1. A radio frequency switch circuit comprising:
a series circuit comprising:
a first series connection group comprising a plurality of first transistors; and
a second series connection group comprising a plurality of second transistors,
wherein control terminals of the first transistors are all coupled to a first control node,
wherein control terminals of the second transistors are all coupled to a second control node,
wherein when an electrostatic discharge event occurs, a voltage at the first control node is different from a voltage at the second control node, and
wherein in a normal operation state, a switch state of the first series connection group and a switch state of the second series connection group are the same as each other.
2. The radio frequency switch circuit according to claim 1 , further comprising:
a first transmitting terminal coupled to a first common node; and
a second transmitting terminal coupled to a second common node, wherein the second transmitting terminal forms a first transmission path with the first transmitting terminal through the second common node and the first common node,
wherein a first terminal of the series circuit is coupled to the second common node.
3. The radio frequency switch circuit according to claim 2 , wherein a second terminal of the series circuit is coupled to the first common node.
4. The radio frequency switch circuit according to claim 2 , wherein a second terminal of the series circuit is coupled to a reference voltage end.
5. The radio frequency switch circuit according to claim 4 , wherein a voltage at the reference voltage end is equal to 0 V.
6. The radio frequency switch circuit according to claim 1 , wherein a number difference between the number of the first transistors and the number of the second transistors is less than 20% of the number of the first transistors.
7. The radio frequency switch circuit according to claim 1 , wherein the number of the first transistors is equal to the number of the second transistors.
8. The radio frequency switch circuit according to claim 1 , wherein the number of the first transistors and the number of the second transistors are both less than 8.
9. The radio frequency switch circuit according to claim 1 , wherein the series circuit further comprises:
a plurality of first matching resistors each coupled between a first terminal and a second terminal of a corresponding one of the first transistors; and
a plurality of second matching resistors each coupled between a first terminal and a second terminal of a corresponding one of the second transistors.
10. The radio frequency switch circuit according to claim 9 , wherein a series resistance of the first matching resistors is the same as a series resistance of the second matching resistors.
11. The radio frequency switch circuit according to claim 9 , wherein an error of resistances of the first matching resistors and an error of resistances of the second matching resistors are less than 20%.
12. The radio frequency switch circuit according to claim 1 , wherein the series circuit further comprises:
a plurality of first choke impedance elements each coupled between the control terminal of a corresponding one of the first transistors and the first control node; and
a plurality of second choke impedance elements each coupled between the control terminal of a corresponding one of the second transistors and the second control node.
13. The radio frequency switch circuit according to claim 1 , wherein:
when the first series connection group is in a turned-off state, the first transistors are turned off, and
when the second series connection group is in a turned-off state, the second transistors are turned off.
14. The radio frequency switch circuit according to claim 1 , wherein when the series circuit is turned on, the series circuit has a low impedance.
15. The radio frequency switch circuit according to claim 1 , wherein the first series connection group and the second series connection group have the same design size.
16. The radio frequency switch circuit according to claim 1 , wherein:
in the normal operation state, the switch state of the first series connection group and the switch state of the second series connection group are controlled by a control circuit,
the control circuit comprises a first control signal generator and a second control signal generator respectively coupled to the first control node and the second control node, and
the first control signal generator provides a first control signal to the first control node, and the second control signal generator provides a second control signal to the second control node.
17. A radio frequency switch circuit comprising:
a radio frequency input terminal;
a radio frequency output terminal having a first transmission path with the radio frequency input terminal; and
a series circuit, wherein a first terminal of the series circuit is coupled to the first transmission path, and a second terminal of the series circuit is coupled to a reference voltage end, wherein the series circuit comprises:
a first series connection group comprising a plurality of first transistors; and
a second series connection group comprising a plurality of second transistors,
wherein a terminal of the second series connection group is coupled to the reference voltage end,
wherein in a normal operation state, a switch state of the first series connection group and a switch state of the second series connection group are the same as each other,
wherein control terminals of the first transistors are all coupled to a first control node,
wherein control terminals of the second transistors are all coupled to a second control node, and
wherein when an electrostatic discharge event occurs, a voltage at the first control node is different from a voltage at the second control node.
18. The radio frequency switch circuit according to claim 17 , wherein:
control terminals of the first transistors are all coupled to a first control node,
control terminals of the second transistors are all coupled to a second control node, and the series circuit further comprises:
a plurality of first choke impedance elements each coupled between the control terminal of a corresponding one of the first transistors and the first control node; and
a plurality of second choke impedance elements each coupled between the control terminal of a corresponding one of the second transistors and the second control node.