Post Silicon Characterization of Digital to Analog Converter using Arduino Uno

This paper explains the characterization process for a DAC (Digital to Analog Converter). Parameters like DNL, INL, gain error, offset error, and their characterization processes have been discussed in detail. A remarkable change has struck the semiconductor industry where open-source Electronic Design Automation tools are being advertised to encourage people towards chip design. Tools like Open Lane support RTL to GDS flow. Companies like Google are facilitating free tape-outs of designs built using opensource PDKs like Sky Water 130 nm PDK. When the ICs are manufactured in large numbers, the fabrication process is not uniform hence, it causes variations in device behavior. Process variations may result in faulty semiconductors that can only be detected when they are tested after the tape out is done. In this paper, characterization of a DAC IC (MCP4921) has been performed without the use of an industry level characterization board and industry-level chip programmer. Arduino Uno which is an open-source micro controller has been used to program the IC by establishing an SPI interface with the DAC IC and the parameters have been measured using instruments like oscilloscope and source measure units which have been automated using Python. Python is also used to store the set of data obtained from the IC and this data is later postprocessed to calculate DC parameters like DNL, INL and Gain Error.