Square wave generating method and square wave generating circuit

Patent metadata

Field	Value
Publication number	US-10622985-B2
Application number	US-201816154736-A
Country	US
Kind code	B2
Filing date	Oct 9, 2018
Priority date	Feb 23, 2017
Publication date	Apr 14, 2020
Grant date	Apr 14, 2020

Abstract

The present application provides a square wave generating method, applied in a square wave generating circuit, configured to generate a mimetic square wave signal, wherein the square wave generating circuit has a breakdown voltage. The square wave generating method comprises the square wave generating circuit generating the mimetic square wave signal as a first voltage during a first time interval; the square wave generating circuit generating the mimetic square wave signal as a second voltage during a second time interval; and the square wave generating circuit generating the mimetic square wave signal as a transient voltage during a transient interval between the first time interval and the second time interval, wherein the transient voltage is between the first voltage and the second voltage; wherein a first voltage difference between the first voltage and the second voltage is greater than the breakdown voltage.

First claim

What is claimed is:

1. A square wave generating method, applied in a square wave generating circuit, configured to generate a mimetic square wave signal, wherein the square wave generating circuit has a breakdown voltage and comprises a first signal generating circuit, a second signal generating circuit, a first switch and a second switch, wherein the square wave generating method comprises:
generating, by the first signal generating circuit, a first pulse comprising a first voltage during a first time interval, such that the mimetic square wave signal comprises the first pulse at the first time interval;
generating, by the second signal generating circuit, a second pulse comprising a second voltage during a second time interval, such that the mimetic square wave signal comprises the second pulse at the second time interval; and
generating, by the square wave generating circuit, the mimetic square wave signal comprising a transient voltage during a transient interval between the first time interval and the second time interval, wherein the transient voltage is between the first voltage and the second voltage;
wherein a first polarity of the first pulse and a second polarity of the second pulse are opposite;
wherein a first voltage difference is formed between the first voltage and the second voltage, and the first voltage difference is greater than the specific breakdown voltage;
wherein the first switch comprises a first MOS transistor comprising a first gate and the second switch comprises a second MOS transistor comprising a second gate;
wherein the first gate and the second gate are not connected.

2. The square wave generating method of claim 1 , wherein a second voltage difference between the first voltage and the transient voltage is equal to the breakdown voltage, or a third voltage difference between the transient voltage and the second voltage is equal to the breakdown voltage.

3. The square wave generating method of claim 1 , wherein the first voltage difference is twice of the breakdown voltage.

4. The square wave generating method of claim 1 , wherein the transient voltage is a grounding voltage.

5. A square wave generating circuit, configured to generate a mimetic square wave signal, wherein the square wave generating circuit has a breakdown voltage, wherein the square wave generating circuit comprises:
an output terminal, configured to output the mimetic square wave signal;
a first signal generating circuit, configured to generate a first pulse comprising a first voltage during a first time interval;
a second signal generating circuit, configured to generate a second pulse comprising a second voltage during a second time interval;
a first switch, one end of the first switch coupled to the first signal generating circuit, and another end of the first switch coupled to the output terminal; and
a second switch, one end of the second switch coupled to the second signal generating circuit, and another end of the second switch coupled to the output terminal;
wherein the first signal generating circuit and the second signal generating circuit generate a transient voltage during a transient interval, the transient interval is between the first time interval and the second time interval;
wherein, the first switch is conducted during the first time interval, such that the mimetic square wave signal comprises the first pulse at the first time interval; the second switch is conducted during the second time interval, such that the mimetic square wave signal comprises the second pulse at the second time interval; the first switch or the second switch is conducted during the transient interval;
wherein a first polarity of the first pulse and a second polarity of the second pulse are opposite;
wherein a first voltage difference between the first voltage and the second voltage is greater than the breakdown voltage;
wherein the first switch comprises a first MOS transistor comprising a first gate and the second switch comprises a second MOS transistor comprising a second gate;
wherein the first gate and the second gate are not connected.

6. The square wave generating circuit of claim 5 , wherein the first switch is controlled by a first control signal, during the transient interval, the first switch is conducted, and the first switch delivers the transient voltage from the first signal generating circuit to the output terminal.

7. The square wave generating circuit of claim 5 , wherein the second switch is controlled by a second control signal, during the transient interval, the second switch is conducted, and the second switch delivers the transient voltage from the second signal generating circuit to the output terminal.

8. The square wave generating circuit of claim 5 , wherein a bulk of the first MOS transistor is coupled to a source of the first MOS transistor, the first MOS transistor is a P-type MOS transistor, a bulk of the second MOS transistor is coupled to a source of the second MOS transistor, the second MOS transistor is a N-type MOS transistor.

9. The square wave generating circuit of claim 8 , wherein the first gate of the first MOS transistor receives a first control signal, the second gate of the second MOS transistor is coupled to a ground terminal; or the second gate of the second MOS transistor receives a second control signal, the first gate of the first MOS transistor is coupled to a ground terminal.

10. The square wave generating circuit of claim 5 , wherein the first signal generating circuit generates a first output signal, an output high voltage level of the first output signal is a positive voltage, and an output low voltage level of the first output signal is a grounding voltage.

11. The square wave generating circuit of claim 10 , wherein the first signal generating circuit comprises a first inverter, an output high voltage level of the first inverter is the positive voltage, and an output low voltage level of the first inverter is the grounding voltage.

12. The square wave generating circuit of claim 10 , wherein the first signal generating circuit generates the first voltage as the positive voltage during the first time interval, and generates the transient voltage as the grounding voltage during the transient interval.

13. The square wave generating circuit of claim 5 , wherein the second signal generating circuit generates a second output signal, an output high voltage level of the second output signal is a grounding voltage, an output low voltage level of the second output signal is a negative voltage.

14. The square wave generating circuit of claim 13 , wherein the second signal generating circuit comprises a second inverter, an output high voltage level of the second inverter is the grounding voltage, an output low voltage level of the second inverter is the negative voltage.

15. The square wave generating circuit of claim 13 , wherein the second signal generating circuit generates the second voltage as the negative voltage during the second time interval.

16. The square wave generating circuit of claim 5 , wherein a second voltage difference between the first voltage and the transient voltage is equal to the breakdown voltage; or a third voltage difference between the transient voltage and the second voltage is equal to the breakdown voltage.

17. The square wave generating circuit of claim 5 , wherein the first voltage difference between the first voltage and the second voltage is twice of the breakdown voltage.

18. The square wave generating circuit of claim 5 , further comprising a first protection unit and a seco

Assignees

• Shenzhen Goodix Tech Co Ltd

Inventors

• Yang Fu-Chiang
• Yang Meng-Ta

Classifications

• H03K17/063 Primary

  in field-effect transistor switches · CPC title

• H03K17/0814

  by measures taken in the output circuit · CPC title

• H03K4/02 Primary

  having stepped portions, e.g. staircase waveform · CPC title

• H03K3/64

  Generators producing trains of pulses, i.e. finite sequences of pulses · CPC title