Digital to analog converter (DAC) and digital to analog conversion method

Abstract

The invention relates to a digital to analog converter (DAC) and a digital to analog conversion method. The DAC comprises a temperature meter encoder, a DEM module matched with a dynamic element, and an action unit array, wherein the temperature meter encoder is used for converting an input signal into a thermometer code; the DEM module is used for generating a random number, and randomizing the thermometer code according to the random number; the action unit array is used for controlling the action of the action unit array according to the randomized thermometer code. The DAC and the digital to analog conversion method are used for reducing relativity between the number of action units of which the states change and the input signal, so as to improve the dynamic linearity of the DAC.

Description

technical field [0001] The invention relates to the field of microelectronics, in particular to a digital-to-analog converter and a digital-to-analog conversion method. Background technique [0002] A digital-to-analog converter (Digital to Analog Converter, DAC for short) is widely used in various electronic circuit systems. In the design process of DAC, a segmented structure is often used to encode different segments of the digital code stream, for example: for an N-bit DAC, encode the N-bit digital code stream, and use a thermometer to encode the high M bits The encoding method, the lower N-M bits adopt binary encoding. Such as figure 1 As shown, it is a schematic diagram of performing thermometer encoding on the upper 4 bits when a 6-bit DAC adopts a segmented structure for encoding in the prior art. In this figure, the upper 4 bits in the digital code stream of the 6-bit DAC are used as input signals for thermometer encoding. coding. Each box in the figure represent...

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Problems solved by technology

[0017] Therefore, in the thermometer encoding method, since the number of current cells whose state changes is related to the input signal, and this correlation will cause the power supply of the DAC to contain a surge current of interference with a frequency of 2ω, and the interference of a frequency of 2ω is very small. It is easy to generate 3ω harmonics of the mixing output with the input signal itself, reducing the dynamic linearity of the DAC

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