Relaxation oscillator for compensating system delay

A relaxation oscillator compensates for system delay. The relaxation oscillator includes first and second input signal units that generates first and second capacitor voltages, a delay compensation unit that receives a reference voltage and the first and second capacitor voltages and that generates a compensation voltage. In certain embodiments, a voltage generating unit applies the reference voltage to the delay compensation unit, and a latch unit stores first and second comparison signals compared by the first and second input signal units and transmits a clock signal and a inverted clock signal to the first and second input signal units. The first and second input signal units compare the first and second capacitor voltages with a compensation voltage transmitted from the delay compensation unit.