Thermal noise canceling pipelined ADC

High resolution pipelined Analog-to-Digital Converters (ADCs) exceeding 10-bits are thermal noise limited. Typically for low-power switched capacitor (SC) circuits, the thermal noise of the op amp is the dominant source of noise as compared to the switches. This paper proposes a thermal noise canceling technique for pipelined stages that cancels the thermal noise of the op amp. The technique involves capturing the noise by an auxiliary DAC and then canceling the noise in the signal path. Circuit level simulations are done in IBM 32 nm SOI process. A case study of thermal noise cancellation for various resolution pipelined ADCs is also done.