An elastic timer for wide dynamic working range

Abstract

Oscillators are needed in many systems for time keeping purposes. They are often called timers. In low duty cycle systems, such as wireless sensors, such oscillators may incur a significant portion of system power consumption. Extensive research exists in making on-chip oscillators low power. However, the other part of the time keeping function, that of computing the number of oscillation cycles, is normally not treated in such research. This paper describes research that focuses on developing oscillators with an innate capability of counting its own oscillation cycles, suitable for direct use as timekeeping devices. The functional correctness of solutions based on asynchronous counters and matched delays are demonstrated and a number of designs are characterized in terms of oscillation frequency and working ranges. In addition, the proposed timers are seamlessly elastic in relation to voltage variations.