Mixed-grained CMOS field programmable analog array for smart sensory applications

The drive towards shorter design cycles for analog integrated circuits has given impetus to the development of Field Programmable Analog Arrays (FPAAs), which are the analogue counterparts of Field Programmable Gate Arrays (FPGAs). In this paper, we present a new design methodology which using FPAA as a powerful analog front-end processing platform in the smart sensory microsystem. The proposed FPAA contains 16 homogeneous mixed-grained Configurable Analog Blocks (CABs) which house a variety of processing elements especially the proposed fine-grained Core Configurable Amplifiers (CCAs). The high flexible CABs allow the FPAA operating in both continuous-time and discrete-time approaches suitable to support variety of sensors. To reduce the nonideal parasitic effects and save area, the fat-tree interconnection network is adopted in this FPAA. The functionality of this FPAA is demonstrated through embedding of voltage and capacitive sensor signal readout circuits and a configurable band pass filter. The minimal detectable voltage and capacitor achieves 38 uV and 8.3 aF respectively within 100 Hz sensor bandwidth. The power consumption comparison of CCA in three applications shows that the FPAA has high power efficiency. And the simulation results also show that the FPAA has good tolerance with wide PVT variations.