Bootstrap circuit and a sampling circuit using the same
A bootstrap circuit including: a charge pump; a power unit including a bootstrap capacitor, wherein the bootstrap capacitor is charged using an output voltage of the charge pump; and a switch driver for generating a bootstrap signal based on a clock signal and an analog signal, wherein the analog signal is input to an analog switch, the switch driver for controlling the analog switch using the bootstrap signal, and including a first body switch connected between an input terminal and a body of the analog switch.
1. A bootstrap circuit, comprising:
a charge pump;
a power unit comprising a bootstrap capacitor connected to the charge pump through a first switch and a second switch, wherein the first switch is connected to a first node of the bootstrap capacitor and the second switch is connected to a second node of the bootstrap capacitor; and
a switch driver comprising:
a third switch connected between the first node of the bootstrap capacitor and a control terminal of an analog switch;
a fourth switch connected between the second node of the bootstrap capacitor and an input terminal of the analog switch; and
a first body switch connected between the input terminal and a body of the analog switch.
2. The bootstrap circuit of claim 1 , wherein the first body switch is configured to operate synchronously with the analog switch.
3. The bootstrap circuit of claim 1 , wherein the switch driver further comprises a fifth switch connected between the control terminal of the analog switch and a first node.
4. The bootstrap circuit of claim 1 , wherein the switch driver further comprises a sixth switch connected between the body of the analog switch and a second node.
5. The bootstrap circuit of claim 1 , wherein the switch driver further comprises a second body switch connected between an input terminal and a body of the first body switch.
6. The bootstrap circuit of claim 5 , wherein the switch driver further comprises a ninth switch connected between a body of the second body switch and a third node.
7. The bootstrap circuit of claim 1 , wherein the switch driver further comprises a seventh switch connected between the first node of the bootstrap capacitor and the third switch.
8. The bootstrap circuit of claim 1 , wherein the switch driver further comprises an eighth switch connected between the second node of the bootstrap capacitor and the fourth switch.
9. A bootstrap circuit, comprising:
a charge pump;
a power unit comprising a bootstrap capacitor connected to the charge pump through a first switch and a second switch, wherein the first switch is connected to a first node of the bootstrap capacitor and the second switch is connected to a second node of the bootstrap capacitor; and
a switch driver comprising:
third and fourth switches connected in series between the first node of the bootstrap capacitor and a control terminal of an analog switch; and
fifth and sixth switches connected in series between the second node of the bootstrap capacitor and an input terminal of the analog switch.
10. The bootstrap circuit of claim 9 , wherein the third and fifth switches of the switch driver are configured to operate in response to a channel selection signal.
11. The bootstrap circuit of claim 9 , wherein the switch driver further comprises a seventh switch connected between the control terminal of the analog switch and a first node.
12. The bootstrap circuit of claim 9 , wherein the switch driver further comprises an eighth switch connected between a body of the analog switch and a second node.
13. The bootstrap circuit of claim 9 , wherein the switch driver further comprises a first body switch connected between the input terminal and a body of the analog switch.
14. The bootstrap circuit of claim 13 , wherein the switch driver further comprises a second body switch connected between an input terminal and the body of the first body switch.
15. The bootstrap circuit of claim 13 , wherein the switch driver further comprises a ninth switch connected between a body of the first body switch and a third node.
16. A sampling circuit, comprising:
a sampling capacitor;
a first analog switch terminal comprising at least one bootstrap circuit connected to the sampling capacitor, wherein the at least one bootstrap circuit comprises:
a charge pump;
a power unit configured to receive an output of the charge pump in response to operation of a first switch of the at least one bootstrap circuit; and
a switch driver comprising:
an analog switch; and
a first body switch connected to a body and an input terminal of the analog switch;
wherein the switch driver is configured to supply a voltage charged in a bootstrap capacitor to an output node in response to operation of a second switch of the at least one bootstrap circuit.
17. The sampling circuit of claim 16 , wherein the at least one bootstrap circuit comprises a second body switch connected between an input terminal and a body of the first body switch.
18. The sampling circuit of claim 16 , wherein the at least one bootstrap circuit comprises a first switch connected between a control terminal of the analog switch and a first node.
19. The sampling circuit of claim 16 , wherein the at least one bootstrap circuit comprises a second switch connected between the body of the analog switch and a second node.
20. The sampling circuit of claim 17 , wherein the at least one bootstrap circuit is configured to perform a multiplexing function based on channel selection signals.