A 12 bit 2.9 GS/s DAC With IM3 <-60 dBc Beyond 1 GHz in 65 nm CMOS

A 12 bit 2.9 GS/s current-steering DAC implemented in 65 nm CMOS is presented, with an IM3 < -60 dBc beyond 1 GHz while driving a 50 Omega load with an output swing of 2.5V(ppd) and dissipating a power of 188 mW. The SFDR measured at 2.9 GS/s is better than 60 dB beyond 340 MHz while the SFDR measured at 1.6 GS/s is better than 60 dB beyond 440 MHz. The increase in performance at high-frequencies, compared to previously published results, is mainly obtained by adding local cascodes on top of the current-switches with always-ON biasing.