Relaxation Oscillator Using Closed-loop Dual Comparator for Biomedical Applications

People's rising concerns about health have fueled research into high-performance biomedical devices and circuits, such as sensors and implantable systems on a chip. It is important for these biomedical devices to operate at the same low frequency to treat certain organs and diseases. Thus, the clock generator needs to be able to provide low frequency clock pulses with minimal size and high reliability. These constraints elevate power consumption and production cost within the circuit design to key parameters. One promising candidate is relaxation oscillator which has good on-chip compatibility, and superior frequency stability. This paper proposes a novel relaxation oscillator using closed-loop dual comparator. A frequency in the band of 50Hz to 2.5kHz can be generated by replacing the value of resistors and capacitor in all possible combinations. The simulation and experimental result confirm that closed-loop dual comparator-based relaxation oscillator provides low frequency with lower cost and more simplicity due to fewer components.