Complementation common-source common-grid inverter and increment Sigma-Delta analog-to-digital conversion circuit

Abstract

The invention provides a complementation common-source common-grid inverter and an increment Sigma-Delta analog-to-digital conversion circuit. The increment Sigma-Delta analog-to-digital conversion circuit is composed of a second-order sigma delta modulator (101), a reduction sampling filter (102), a clock signal generation circuit (103) and a low-to-high voltage converter (104). A switch capacitance integrator at the band reset end of the second-order sigma delta modulator (101) comprises the complementation common-source common-grid inverter. The complementation common-source common-grid inverter comprises a first PMOS1 tube and a first NMOS1 tube. A second NMOS2 tube and a second PMOS2 tube are connected in series between the first PMOS1 tube and the first NMOS1, the second NMOS2 tube is arranged at an upper position, the grid end of the second NMOS2 tube is connected with a power supply voltage VDD, the second PMOS2 tube is disposed at a lower position, and the grid end of the second PMOS2 tube is grounded GND. The ADC provided by the invention has quite low power consumption and can work under the condition of low power supply voltage, thereby being applied to such fields of a portable instrument, measuring, and the like.

Description

technical field [0001] The invention relates to a low-voltage and low-power incremental ΣΔ analog-to-digital converter. Background technique [0002] Sigma-Delta (ΣΔ) analog-to-digital converter (ADC) is widely used in communication and multimedia fields due to its simple structure, low power consumption, high precision and no need for device matching. However, the traditional ΣΔ structure is not suitable for instrumentation and measurement applications, where very high accuracy and linearity are required, and very low offset and gain errors are required in addition to high dynamic range and signal-to-noise ratio. The traditional ΣΔADC only focuses on dynamic characteristics such as signal-to-noise ratio and effective bits. Incremental ΣΔADC is very suitable for instrumentation and measurement fields, because it can provide low offset, low gain error, point-to-point, high-precision analog-to-digital conversion, and the conversion time is relatively short. [0003] In areas...

AI Technical Summary

Problems solved by technology

However, two important problems with this method are: the gain and bandwidth are severely limited; since the inverter has no virtual point, it needs to be self-established, resulting in extremely strong process sensitivity for the DC operating point and the AC characteristics of the inverter

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