"The CMOS inverter" as a comparator in ADC designs

This paper introduces a single-ended non-offset-cancelled flash ADC architecture, the "Threshold Inverter Quantizer" (TIQ). The TIQ is based on a CMOS inverter cell, in which the voltage transfer characteristics (VTC) are changed by systematic transistor sizing. As a result, a significant improvement of speed and reduction of area and power consumption is achieved. A sample TIQ based flash ADC chip including 3-bit, 4-bit and 6-bit versions together has been designed and fabricated with the 2 μ standard CMOS n-well technology. The proposed ADC cells are suitable for System-on-Chip (SoC) applications in high speed wireless products.