Low voltage digital-to-analog converter with improved accuracy

Abstract

An apparatus for generating an analog output signal representative of a digital input signal, which digital input signal is received as a plurality of bits. The apparatus includes a current branch array for establishing a plurality of output current branches and a reference current branch. The current branch array includes a first, a second, and a third electrical node. Each respective output current branch is responsive to a respective bit to switchably connect the respective output current branch intermediate the first and the second electrical node when the respective bit is a first state and to switchably connect the respective output current branch intermediate the first and the third electrical node when the respective bit is in a second state. Each respective output current branch and the reference current branch includes a respective switching device which responds to a switching signal to enable current flow through the first electrical node. The apparatus further includes a switching control device for controlling generation of the switching signal. The switching control device has a first input operatively connected with the second electrical node and a second input operatively connected with the reference current branch. The switching control device generates the switching signal and conveys the switching signal to each of the respective switching devices when the first input and the second input have a predetermined mutual relationship.