A 0.5V 6-bit scalable phase interpolator

This paper proposes a scalable phase interpolator (PI) with dual-input inverter. A pseudo-pipelined architecture is proposed to realize resolution scalability and to reduce the circuit size and power consumption. By using a simple architecture, the proposed circuit operates at 0.5V at which conventional analog PI cannot operate. Slew rate of inverter chain is controlled by current starving technique to support phase interpolation at wide input frequency range. The PI was designed in 65nm-CMOS technology. The circuit simulation confirms 6-bit phase resolution, DNL of 0.41 LSB, and INL of 1.25 LSB. The power consumption is 0.12 μW/MHz.