A Submicrowatt 1.1-MHz CMOS Relaxation Oscillator With Temperature Compensation

A low power low supply sensitivity current-mode relaxation oscillator

“…In [3], a low-power current-mode relaxation oscillator has also been proposed, since the delay is inversely proportional to supply voltage, the output frequency shows a positive variation when supply voltage increases. Moreover, the duty cycle of the oscillator signal is not 50%, an additional clock divider is needed to generate a proper 50% duty cycle signal.…”

“…As an important component, on-chip oscillators are widely employed in those SoCs for timing reference. For a portable device, the volume and battery life are two of the critical issues [3]. For most batteries, the output voltage will drop over the operating time, a low-power on-chip oscillator with low supply sensitivity can not only extend the battery life but also reduce the circuitry volume.…”

“…Ring oscillators [5] are considerably accurate, but consume several hundred microwatts. Relaxation oscillators [3,6,7,8,9] can achieve good temperature performance while operate at lower power, which is extremely suitable for low power applications.…”

Triangle/Square Waveform Generator Using Area Efficient Hysteresis Comparator

“…In [1] a capacitor is linearly charged and the threshold is compared with a current-mode comparator. In [2] a voltage on an exponentially charged capacitor is compared with a hysteresis comparator. However, for some applications, such as DC-DC converters [3], a triangular waveform may be required.…”

High-Robust Relaxation Oscillator with Frequency Synthesis Feature for FM-UWB Transmitters

“…The existing oscillators [7][8][9][10] with temperature immunity lack enough consideration of, or are sensitive to process deviations. The existing oscillators [11][12][13] with good PVT robustness have large power dissipation in comparison to low oscillation frequency, which causes poor figure of merit (FOM) values.…”