Loading [a11y]/accessibility-menu.js
A Capacitance-Ratio-Modulated Current Front-End Circuit With Pulsewidth Modulation Output for a Capacitive Sensor Interface | IEEE Journals & Magazine | IEEE Xplore

A Capacitance-Ratio-Modulated Current Front-End Circuit With Pulsewidth Modulation Output for a Capacitive Sensor Interface


Abstract:

This paper presents a front-end circuit with pulsewidth modulation (PWM) output for a capacitive sensor interface. A single-MOSFET-based capacitance-ratio-modulated curre...Show More

Abstract:

This paper presents a front-end circuit with pulsewidth modulation (PWM) output for a capacitive sensor interface. A single-MOSFET-based capacitance-ratio-modulated current (CRMC) circuit is proposed to transform the sensed capacitance into a current proportional to a capacitance ratio. The proposed single-MOSFET-based CRMC circuit not only saves a lot of chip area but also lowers power consumption. Then, a dual-slope integration circuit transforms further the modulated current into PWM output. A prototype chip is designed and fabricated with a 0.35-μm complementary metal-oxide-semiconductor process and has a core area of 0.09 mm2. The measurement results of the prototype chip demonstrate an accuracy value of up to 9.3 bit with 54-μW power consumption. The microwatt power consumption and the small chip area of the proposed front-end circuit make it very suitable for a capacitive sensor interface in smart sensor chips.
Published in: IEEE Transactions on Instrumentation and Measurement ( Volume: 61, Issue: 2, February 2012)
Page(s): 447 - 455
Date of Publication: 05 September 2011

ISSN Information:


References

References is not available for this document.