CMOS A SENSOR CIRCUIT INTEGRATING STANDARD CMOS SENSORS ENHANCING ENERGY EFFICIENCY AND A SENSOR APPARATUS COMPRISING IT

摘要

We present an environmental information sensor circuit and an environmental information measuring device that can easily reduce quantization noise and sense various environmental information such as pressure, humidity, and acceleration by adopting a dual quantization capacitance-to-digital converter structure. The proposed environmental information sensor circuit is a switch capacitor that outputs one of pressure information, humidity information, and acceleration information based on the non-overlapping first and second clock signals, and an integrator that integrates the output of the switch capacitor and outputs an analog value. And a single bit first delta sigma converter including a single bit quantizer that compares the output of the integrator with a preset threshold voltage and outputs a single bit digital signal corresponding to the comparison result, and connected to the output terminal of the integrator via a sampling switch. And a multi-bit quantizer that quantizes the output of the integrator at the time the sampling switch is turned on according to the sampling signal.