A Proposed Method to Extend One-Bit of the Parallel Interface in a Digital to Analog Conversion Circuit by Adding an External Device

In this paper, we propose a method to extend one bit to a parallel interface type Digital to Analog conversion circuit by using an external device. The examination of the Digital to Analog conversion circuit's principle is conducted in order to perform the aforementioned extension. Additionally, an analysis is carried out to identify the problems that arise when extending one bit using additional individual devices. Subsequently, a bit extension system for the Digital to Analog conversion device is proposed, utilizing an operational amplifier circuit. This method is utilising the high-precision characteristics of the operational amplifier, which affects the size of the output waveform only even when an error occurs in the device, and the voltage reversal phenomenon occurring between the bits doesn’t take place. To verify the effectiveness of the method proposed, we constructed the circuitry for experiment and measured the absolute voltage and relative error of the output waveform. According to the experimental results, it was confirmed that only 0.0756% error occurred on average compared to the 12-bit class Digital to Analog converter. According to these results, we confirmed that one bit extension is possible by adding a small number of individual devices.