Single Chip Dual Plate Capacitive Proximity Sensor With High Noise Immunity
- Resource Type
- Periodical
- Authors
- Kim, Y. S.; Cho, S.-I.; Shin, D. H.; Lee, J.; Baek, K.-H.
- Source
- IEEE Sensors Journal IEEE Sensors J. Sensors Journal, IEEE. 14(2):309-310 Feb, 2014
- Subject
- Signal Processing and Analysis
Communication, Networking and Broadcast Technologies
Components, Circuits, Devices and Systems
Robotics and Control Systems
Capacitive sensors
Amplifiers
Noise
Switches
Capacitors
Cutoff frequency
Proximity sensor
capacitive
dual plate
noise immunity
- Language
- ISSN
- 1530-437X
1558-1748
2379-9153
This letter presents a dual plate capacitive proximity sensor (PS) that is integrated into a single chip with high environmental noise immunity. To efficiently reject environmental noise, the proposed PS employs two noise rejection techniques: 1) the use of a switched-charge amplifier and 2) synchronous sampling/filtering technique. The proposed PS is fabricated using a standard CMOS 0.5-$\mu{\rm m}$ process, and it occupies an area of 0.7 mm $\times\,$0.3 mm. Experimental results show that the proposed PS can detect an object up to 8 cm away from the sensor at an average current of 370 $\mu{\rm A}$ with a resolution of 1% output frequency.