A smart sensory platform based on field programmable analog array

This paper presents a smart sensory platform based on Field Programmable Analog Array (FPAA) to support a wide variety of MEMS sensors applications. A discrete-time (DT) and continuous-time (CT) dual-mode FPAA is proposed to improve the analog signal conditioning flexibility. A gain-programmable low-noise multi-mode sensor Readout Circuit (RoC) is designed for versatile sensor weak signal acquisition, which can sense capacitive, voltage or current signal. A microcontroller (MCU) and a 12-bit SAR ADC are used for digital signal processing and analog-digital conversion. The platform is implemented in 0.18μm CMOS process. The multi-mode sensor readout circuit achieves an input referred noise of 140nV/√Hz, 200pA/√Hz and 5aF/√Hz for voltage, current and capacitive signal readout mode, respectively. Analog signal processing functions, such as CT PGA, DT filter, CT adder and comparator, are realized through the configuration of the dual-mode FPAA. The SAR ADC shows 10.2bit effective number of bits with 450μA power consumption at 1Msps sampling rate.