CN-121984488-A - Grid voltage bootstrapping switch

CN121984488ACN 121984488 ACN121984488 ACN 121984488ACN-121984488-A

Abstract

The invention provides a gate voltage bootstrapping switch circuit structure, which relates to the technical field of analog integrated circuit design, and comprises a bootstrapping capacitor unit and a charge pump unit, wherein the bootstrapping capacitor unit comprises a bootstrapping capacitor, 6 switching tubes and two pairs of inverters, the bootstrapping capacitor unit charges the bootstrapping capacitor in a holding stage by controlling the switches of the 6 switching tubes, the bootstrapping capacitor unit enables the gate voltage of the bootstrapping switching tubes to follow an input signal in a following stage to enable the gate source power supply to be kept at a fixed value, the charge pump unit mainly accelerates the charging of the bootstrapping capacitor unit, and the gate voltage bootstrapping switch circuit can reduce the correlation between the on resistance of the sampling switch and the sampling signal, so that the linearity of an integral sampling network is improved, and meanwhile, the charge and the discharge of the capacitor are accelerated through the charge pump.

Inventors

YUAN YONGBIN
LIAO YONG
LIANG JIANGSHAN
BAI JINSONG

Assignees

贵州木弓贵芯微电子有限公司

Dates

Publication Date: 20260505
Application Date: 20251224

Claims (5)

1. A gate voltage bootstrapped switch, comprising: The bootstrap capacitor unit comprises a bootstrap capacitor, 6 switching tubes and two pairs of inverters, the bootstrap capacitor is charged in a holding stage by controlling the switching of the 6 switching tubes, and the bootstrap capacitor enables the gate voltage of the bootstrap switching tubes to follow an input signal in a following stage so that a gate-source power supply is kept to be a fixed value; The charge pump unit comprises two capacitors and 3 transistors, and the charge pump unit mainly accelerates the charging of the bootstrap capacitor.
2. The bootstrap switch of claim 1, wherein the bootstrap capacitor unit comprises a first capacitor, a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor, a sixth transistor, a seventh transistor, an eighth transistor, a ninth transistor, and a tenth transistor, wherein an upper plate of the first capacitor is connected to a source of the eighth transistor and a source of the fourth transistor, a lower plate of the first capacitor is connected to a drain of the seventh transistor and a source of the first transistor, a source of the second transistor is grounded, a gate of the second transistor is connected to a reference clock in a reverse direction, a drain of the second transistor is connected to a source of the third transistor, a drain of the third transistor is connected to a drain of the fourth transistor and a gate of the first transistor, a gate of the fourth transistor is connected to a drain of the fifth transistor and a drain of the sixth transistor, a drain of the fifth transistor is connected to a drain of the fifth transistor, a drain of the fifth transistor is connected to a drain of the seventh transistor and a drain of the eighth transistor is connected to a drain of the eighth transistor, a drain of the eighth transistor is connected to a reference clock, a drain of the ninth transistor is connected to a drain of the eighth transistor, and a drain of the ninth transistor is connected to a drain of the reference clock.
3. The gate voltage bootstrapped switch of claim 1, wherein the charge pump unit includes a second capacitor, a third capacitor, an eleventh transistor, and a twelfth transistor, a lower plate of the second capacitor is connected to a reference clock, an upper plate of the second capacitor is connected to a gate of the twelfth transistor and a source of the eleventh transistor, a lower plate of the third capacitor is connected to a reverse reference clock, an upper plate of the third capacitor is connected to a gate of the eleventh transistor and a source of the twelfth transistor, and a drain of the eleventh transistor and a drain of the twelfth transistor are connected to a reference power supply.
4. The gate voltage bootstrapped switch of claim 2, wherein the first transistor, the sixth transistor, the seventh transistor, the eighth transistor, the tenth transistor are NMOS transistors, and the second transistor, the third transistor, the fourth transistor, the fifth transistor, the ninth transistor are PMOS transistors.
5. The gate voltage bootstrapped switch of claim 3, wherein the eleventh transistor and the twelfth transistor are NMOS transistors.

Description

Grid voltage bootstrapping switch Technical Field The invention relates to the field of integrated circuit design, in particular to a grid voltage bootstrap switch Background With the continued development of semiconductor technology, integrated circuits are known as important pillars in the information industry. The integrated circuit can complete the functions of information acquisition, amplification, comparison, conversion, transmission, power supply and the like, and plays an important role in modern information systems such as information sensing, communication, processing, control, use and the like. Digital information is easy to store and transmit, while acoustic, optical, thermal, electrical, force, etc. information in the real physical world is analog information. In order to connect two different worlds and realize the mutual conversion of analog information and digital information, a data converter is provided, a sampling switch is an important circuit in front-end sampling of the data converter, and the overall performance of the data converter is greatly affected. The sample and hold circuit is used as the first important unit for the input signal to pass through in each pipeline sub-stage in the pipelined ADC, and the sampling linearity of the sample and hold circuit directly determines the maximum linearity of the output of the subsequent stage. In particular, the sample-and-hold circuit of the first stage MDAC in the pipelined ADC directly determines the maximum linearity of the whole ADC, so the design of the sample-and-hold circuit is very important, and the sample-and-hold circuit generally consists of a sampling switch and a sampling capacitor. When the sampling switch is turned on, the input signal VIN is sampled, VOUT changes along with VIN, after the sampling switch is turned off, the VOUT keeps the value of the switching-off moment VIN, the sampling switch is usually realized by an MOS device, and when a single MOS tube is used as the sampling switch, the on resistance and the channel charge of the MOS tube can change along with the change of the input signal, so that the linearity of the sampling circuit is greatly affected. The principle of the grid voltage bootstrap circuit is that the grid source voltage of the MOS tube is kept constant all the time in the sampling process, the on-resistance of the sampling switch is kept unchanged in the sampling process, so that the linearity of sampling can be improved, the grid voltage bootstrap switch not only can have lower resistance value under the switch MOS tube with smaller size, the sampling speed of the ADC under high sampling rate is ensured, but also can keep the grid source voltage of the sampling switch constant all the time in the on-process of the sampling switch, so that the on-resistance of the sampling switch in the sampling process is ensured to be relatively stable, but the charge-discharge speed of the bootstrap capacitor of the traditional grid voltage bootstrap switch is slow, so that the bootstrap effect is not ideal in the high-speed application. Disclosure of Invention The invention provides a gate voltage bootstrap switch to solve the problems that on-resistance changes along with input signal changes and the charge and discharge speed of a bootstrap capacitor is slow in a related art sampling switch. In order to achieve the above purpose, the invention adopts the following technical scheme: a gate voltage bootstrapped switch, comprising: The bootstrap capacitor unit comprises a bootstrap capacitor, 6 switching tubes and two pairs of inverters, the bootstrap capacitor is charged in a holding stage by controlling the switching of the 6 switching tubes, and the bootstrap capacitor enables the gate voltage of the bootstrap switching tubes to follow an input signal in a following stage so that a gate-source power supply is kept to be a fixed value; The charge pump unit comprises two capacitors and 3 transistors, and the charge pump unit mainly accelerates the charging of the bootstrap capacitor. The bootstrap capacitor unit comprises a first capacitor, a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor, a sixth transistor, a seventh transistor, an eighth transistor, a ninth transistor and a tenth transistor, wherein an upper plate of the first capacitor is connected with a source electrode of the eighth transistor and a source electrode of the fourth transistor, a lower plate of the first capacitor is connected with a drain electrode of the seventh transistor and a source electrode of the first transistor, a source electrode of the second transistor is grounded, a grid electrode of the second transistor is connected with a reverse reference clock, a drain electrode of the second transistor is connected with a source electrode of the third transistor, a drain electrode of the third transistor is connected with a reference power supply, a drain electrode of the fourth tra