DEM (Dynamic Element Matching) encoding method for current rudder DAC (digital to analog converter)

Abstract

The invention discloses a DEM (Dynamic Element Matching) encoding method for a current rudder DAC (digital to analog converter), relating to the field of DEM encoding. The method comprises the following steps of: judging the size relation between the digital Input (n) of the current period of the current rudder DAC and the digital Input (n-1) of the last period of the current rudder DAC; if the digital Input (n) is equal to the digital Input (n-1), keeping output of a DEM module unchanged, and keeping Pstart and Pend values of a printer unchanged; if the digital Input (n) is more than the digital Input (n-1), carrying out first setting operation on the output of the DEM module, and correcting the Pstart and Pend values; and if the digital Input (n) is less than the digital Input (n-1), carrying out second setting operation, and correcting the Pstart and Pend values. According to the method disclosed by the invention, the hop switching number of each period is effectively reduced, and therefore dynamic errors caused by switch hop is reduced.

Description

technical field [0001] The invention relates to the field of DEM encoding, in particular to a DEM encoding method for a current steering DAC. Background technique [0002] Due to the deviation of the production process and the inconsistency of the working temperature and voltage, the chip components (such as transistor size, threshold voltage and resistance value, etc.) will be mismatched, which will seriously affect the performance of the system, especially the linearity. DEM (Dynamic Element Matching, Dynamic Element Matching) coding method can convert the distortion caused by component mismatch into noise, thereby effectively improving the linearity of the system, so it is widely used in ADCs and DACs of various structures. figure 1 It is a working schematic diagram of a traditional DAC including a DEM module. like figure 1 As shown, after the digital input of the DAC is coded by the DEM module, M digital bits are output ( figure 1 Middle C 1 to C M ), the M digital ...

AI Technical Summary

Problems solved by technology

[0003] However, traditional DEM encoding methods (such as Data Weighted Averaging, DWA) will drastically increase the number of switches per sampling period, and too many switch transitions will cause large dynamic errors (switch transitions are not synchronized, clock feed communication, etc.), which also affects the performance of the system

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