A gate voltage bootstrap switch circuit

Abstract

A gate voltage bootstrap switch circuit belongs to the field of analog integrated circuit design. It includes a main switching tube Ms, a grid voltage boosting circuit, a switching circuit, an input signal Vin, and an output signal Vout; the grid voltage boosting circuit includes a bias module, a load module, and two triodes connected in an emitter-follower mode for changing The gate terminal voltage of the main switching tube is to realize its gate-source voltage as a constant value; the switch circuit is a transistor, which is used to control the opening and closing of the gate voltage boosting circuit; the input signal Vin passes through two gate voltage boosting circuits The triode connected in the form of an emitter follower is connected to the gate terminal of the main switching transistor Ms, and the source terminal of the main switching transistor Ms is connected to the output signal Vout. The invention provides a gate voltage bootstrap switch circuit without a bootstrap capacitor, which not only eliminates the problem of charge sharing caused by parasitic capacitors, but also effectively reduces the circuit area.

Description

technical field [0001] The invention belongs to the field of analog integrated circuit design, in particular to a gate voltage bootstrap switch circuit. Background technique [0002] With the rapid development of modern communication technology and signal processing technology, the demand for high-speed, high-precision semiconductor integrated circuits is increasing. In the field of signal processing, it is necessary to convert the analog signal into a digital signal, and then carry out further processing through the digital signal processing module. In the process of converting an analog signal to a digital signal, in order to meet the requirement for high linearity sampling of the analog signal, a gate voltage bootstrap switch circuit is usually required. [0003] The traditional gate voltage bootstrap switch circuit structure such as figure 1 As shown, by the main switch tube M s and a gate voltage bootstrap circuit, where the gate voltage bootstrap circuit includes a ...

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Problems solved by technology

[0011] However, when the phase is turned on, the MOS transistor (M 1 ~ M 5 ) of parasitic capacitance (C GS 、C GD 、C SB 、C DB etc.) with the bootstrap capacitor C 1 Charge sharing will occur, resulting in the loss of charge on the bootstrap capacitor, reducing the voltage at the gate terminal of the main switch, thereby reducing the on-resistance; at the same time, the capacitance of the above-mentioned parasitic capacitor is directly related to the input voltage, which will further deteriorate the linearity of the switching circuit

In order to reduce the influence of parasitic capacitance, the traditional bootstrap switch circuit is usually implemented by increasing the bootstrap capacitance, but this will increase the chip area and increase the cost

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