Patent ID: 7369077

Claim:
A differential current-steering digital-to-analogue converter (DAC), the DAC comprising: a digital input to receive a binary code comprising a plurality of bits defining a signed digital value for conversion into a signed differential analogue output signal; a pair of differential analogue output lines to provide said differential analogue output; and a set of binary-weighted steerable substantially constant current generators each coupled to said differential output lines and having a control input to receive a signal derived from said digital input to control current steering to said differential output lines responsive to said binary input code; wherein a said steerable substantially constant current generator comprises a ternary substantially constant current generator configured to generate a three-state differential current in response to a ternary signal on said control input; wherein each of said ternary current generators is associated with a bit of said binary code; and wherein said DAC further comprises a code converter coupled between said DAC digital input and said control inputs of said steerable current generators to convert said binary input code to a ternary code to control said steerable current generators.