A Low-Spurious Low-Power 12-bit 160-MS/s DAC in 90-nm CMOS for Baseband Wireless Transmitter

A low-spurious low-power 12-bit 160-MS/s digital to analog converter (DAC) for baseband wireless transmitter is proposed and demonstrated. Degenerated current switches are introduced and benefits of using them are discussed. Mismatch behavior under packaging-induced die stress is also presented. The mobility shift caused by package stress inherited from a thin-die is a dominant source of I/Q mismatch. A 2-channel I/Q DAC core consumes 4 mA with a 1.3/2.6 V dual supply. The 0.13 mm² I/Q DAC core fabricated in 90-nm digital CMOS process with a highly-integrated digital processor achieves 74 dB SFDR, 55 dB SNDR, and -73 dB THD for a 975 kHz sinusoid at 153.6 MS/s sample rate.