Patent attributes
A current controller includes impedance elements coupled to form at least one impedance ladder circuit which exhibits a fixed impedance at an input and current divider steps each differing in a current magnitude by a multiple of three with respect to the current magnitude in an adjacent less significant step. Single pole triple throw (SPTT) switchably couple an associated step in the impedance ladder circuit to one of three outputs. Three discrete current sources or sinks are each coupled to a corresponding one of the outputs of each of the SPTT switches. The digital driver is coupled to each control input of each SPTT switch to additively deliver selected ones of the stepped currents from each step of the impedance ladder circuit to a corresponding selected one of the current sources or sinks.
