A Time-Encoded Capacitance-to-Digital Converter Based on a Switched-Capacitor Feedback Articles uri icon

publication date

  • September 2023

start page

  • 1

end page

  • 4


  • 11


  • 7

International Standard Serial Number (ISSN)

  • 2475-1472


  • An innovative method to perform capacitance-to-digital conversion without requiring sensor biasing circuitry is proposed. This letter is intended for the readout of MEMS capacitive microphones used in human-to-machine interface applications, where the main constraints are low power consumption and small chip area. The time-encoded sigma-delta ADC described here employs a switched-capacitor-based feedback to linearize the voltage-controlled oscillator and to couple the capacitive sensor to the readout. A prototype was fabricated to test the concept with a CMOS 130-nm process.


  • Electronics


  • sensor signal processing; capacitance; converter; digital; mems; microphone; sensor; sigma-delta; time-encoding; vco-adc