DAC capacitor array and analog-digital converter, method for lowering power consumption of analog-digital converter

Abstract

The embodiments of the invention belong to the field of integrated circuits, and relates to a DAC capacitor array and an analog-digital converter, and a method for lowering power consumption of an analog-digital converter. The DAC capacitor array includes a plurality of sub-capacitor arrays which are in parallel connection. Each sub-capacitor array includes capacitor groups. Each capacitor group includes N capacitors which are in parallel connection, wherein N is an integer. Each sub-capacitor array also includes a primary path switch and a plurality of multi-path selective switches. One end of each capacitor of the capacitor group is connected to an input end of a comparator and is connected to one input source of the primary path switch, and the other end of each capacitor of the capacitor group is connected to a plurality of input sources through a corresponding multi-path selective switches. The DAC capacitor array is optimized by adjusting the reference voltage connected to each capacitor of the DAC capacitor array, and reduces the capacitance of the entire DAC capacitor array, such that a SAR type analog-digital converter is reduced in size, power consumption is reduced, and the cost of manufacturing chip is reduced as well.

Description

technical field [0001] Embodiments of the present invention belong to the field of integrated circuits, and in particular relate to a DAC capacitor array, an analog-to-digital converter, and a method for reducing power consumption of the analog-to-digital converter. Background technique [0002] The successive approximation analog-to-digital converter (Successive Approximation Analog-to-digital converter, SAR ADC) can convert the analog signal into a digital signal, refer to figure 1 , which is composed of a comparator, a register, and a digital-to-analog converter (Digital-to-analog converter, DAC). The basic principle of converting an analog signal into a digital signal is: the analog input signal to be converted is compared with a reference signal In comparison, the reference signal is obtained from the output of a D / A converter. According to the size of the two, it is decided to increase or decrease the digital signal input by the D / A converter, so that the reference sig...

AI Technical Summary

Problems solved by technology

However, if there are too many capacitors arranged in a binary weighted arrangement, the overall capacitor size will be too large, which will increase the power consumption of the circuit, and even offset the power consumption of the circuit reduced by changing the reference voltage of the unit capacitor on the right.

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