| Title |
A Design of Low-power, High-resolution Capacitance-to-pulse Time Converters based on OTA-C Integration |
| Authors |
이재본(Jae-Bon Lee) ; 장두진(Doojin Jang) ; 박지만(Ji-Mann Park) |
| DOI |
https://doi.org/10.5573/ieie.2026.63.4.29 |
| Keywords |
Capacitance-to-pulse time converter; Ramp-integrator; Linear OTA; Low-power; High-resolution |
| Abstract |
This paper proposes a low-power, high-resolution Capacitance-to-Pulse Time Converter using an OTA-C based 2-stage integrator and a comparator for high-precision instruments and measurement systems. The OTA-C based integrator generates a small, linear current proportional to the input voltage. This allows for a long integration time, resulting in a large pulse-width even for minute capacitance variations of the sensor. This pulse-width can be further extended by connecting an additional large external capacitor. The proposed converter was simulated using a 180 nm CMOS process. With a capacitance variation range of up to 1 pF, the converter generates a maximum pulse-width of approximately 2.909 ms. When a 5.6 MHz clock signal is used, it achieves a 14 bit resolution with 13.4 bit ENOB and a power consumption of 156 uW. The proposed converter demonstrates that low-power consumption and high-resolution can be effectively achieved using a low-speed clock signal, and it is expected to be widely applicable to high-precision instruments and IoT measurement systems. |