This work describes a novel approach for interfacing capacitive sensors in the sub-pF range. The system generates aPWMsignal with a linear relationship between the pulse duration and the sensor capacitance. The circuit exhibits intrinsic low sensitivity to temperature and process variations and is therefore an interesting solution when extremely wide operating temperature ranges are required. A detailed analysis of the noise characteristics, aimed to give indications about the circuit optimisation, is presented. The interface has been designed using the 0.35 μm BCD6 process of STMicroelectronics and tested by means of electrical simulations.
A precise capacitance-to-Pulse-Width Converter for Integrated Sensors
BRUSCHI, PAOLO;BARILLARO, GIUSEPPE;
2004-01-01
Abstract
This work describes a novel approach for interfacing capacitive sensors in the sub-pF range. The system generates aPWMsignal with a linear relationship between the pulse duration and the sensor capacitance. The circuit exhibits intrinsic low sensitivity to temperature and process variations and is therefore an interesting solution when extremely wide operating temperature ranges are required. A detailed analysis of the noise characteristics, aimed to give indications about the circuit optimisation, is presented. The interface has been designed using the 0.35 μm BCD6 process of STMicroelectronics and tested by means of electrical simulations.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
