Method for improving the accuracy of an exponential current digital-to-analog (IDAC) using a binary-weighted MSB

摘要

A method for the design synthesis of an exponential current digital-to-analog (IDAC) using a binary-weighted MSB. The design synthesis involves defining an exponential LSB and exponential MSB current mirrors according to a defined methodology. A method to achieve an exponential current digital-to-analog converter (IDAC) having improved accuracy using a binary-weighted most significant bit (MSB) comprising (1) defining a differential non-linearity (DNL); (2) defining number of LSB bits needed for the targeted DNL with a binary weighted MSB; (3) calculating the number of bits to be used for the binary-weighted MSB to get the desired IDAC base; (4) deriving the minimum current for the Imax; (5) defining the LSB as an exponential current mirror according to the specified relationship for the ILSB; and (6) defining a binary-weighted MSB according to the specified relationship for IMSB.