High Speed Digitizer for a Contactless Potentiometric Displacement Sensor
- Resource Type
- Conference
- Authors
- Jha, Subham Kumar; Sohail, Shiraz; Singh, Gopal; Kumar, Nandigama Praveen; Islam, Tarikul
- Source
- 2024 IEEE Applied Sensing Conference (APSCON) Applied Sensing Conference (APSCON), 2024 IEEE. :1-4 Jan, 2024
- Subject
- Engineering Profession
General Topics for Engineers
Capacitors
Switches
Sensors
Circuit synthesis
Analog-digital conversion
Switching circuits
Clocks
Contactless potentiometer
displacement sensor
dual slope analog to digital converter (ADC)
resistance to digital converter
- Language
This work presents a high-speed digitizer circuit for interfacing a contactless potentiometric displacement sensor (CPOT) which is simple to realize. The circuit comprises a dual-slope integrator and a comparator that work together to produce a digital time sequence output signal. The feedback of the integrator consists of a T-Network which is realized using three branches of the CPOT. The small value air capacitor of the wiper $(5~pF$) of CPOT is used for integration operation, so it requires a small measurement time $(0.70~{ms})$. The other two branches ($R_{2}$ and $R_{3}$) of the CPOT are switched between the ground and virtual ground of the integrator during the charging and discharging of the capacitor respectively. Avoiding the use of switched capacitor technique in the circuit leads to a reduced number of switches, eliminating the need for a clock signal, and simplifies the circuit significantly. The CPOT used for simulation is $100~\mathrm{k}\Omega$ which is varied in a step change of $5~\mathrm{k}\Omega$. The circuit exhibits an average error of ± 0.64%.