Multi-bit comparator with combination of time and digital converter and voltage digitizing method

Abstract

The present invention relates to a multi-bit comparator with the combination of a time and digital converter and a voltage digitizing method. The multi-bit comparator comprises a one-bit comparator, a time and digital converter, an inverter, and an XOR gate. The input end of the one-bit comparator is connected to the positive and negative ends of an input signal and a clock signal. The input end of the XOR gate is connected to the output end of the one-bit comparator. The input end of the time and digital converter is connected to the output end of the XOR gate and the clock signal which is processed by the inverter. According to the multi-bit comparator, by using the relation that the judgment time of the comparator in low voltage is increased with the reduction of input voltage, a judgment time is converted into a corresponding digital code through TDC conversion, thus the digitization of low power consumption and high precision small signal voltage is realized, and the multi-bit comparator and the method have the advantages of low power consumption, adaption to low-voltage design, small size and fast speed.

Description

technical field [0001] The invention belongs to the field of analog integrated circuits and digital integrated circuits, and relates to a comparator, in particular to a multi-bit comparator combined with a time-to-digital converter, and a method for realizing voltage multi-bit quantization by using the multi-bit comparator. Background technique [0002] With the development of digital processing technology, more and more information systems use digital signal processors to complete various operations. Most external signals are continuous analog signals. At this time, an analog-to-digital converter (A / D Converter) is needed as an interface between the analog world and the digital world to convert continuous analog signals into discrete digital signals and corresponding codes. [0003] The comparator (Comparator) is the key unit responsible for quantization in the analog-to-digital converter, and it is also widely used in many fields. Generally, the comparator can be regarded ...

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Problems solved by technology

However, this kind of comparator has the problem of metastable state, especially when the voltage difference of the input signal is small, the time of the comparator in the metastable state is greatly extended

Taking an 8-bit analog-to-digital converter as an example, at a power supply voltage of 1V, the corresponding minimum input signal is 4mV, and the judgment time of the comparator at this time is about 100 picoseconds; but at a power supply voltage of 0.5V, the comparison at this time The device decision time will be extended to about 100 nanoseconds

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