Op amp sawtooth wave generator circuit

The sawtooth wave generator shown in the figure resets at the end of each cycle. The result is an output with a fixed peak-to-peak value over the frequency range of the circuit. Constant current generator circuit, voltage follower circuit and comparator circuit produce sawtooth waveform. A 555 timer circuit (U2) acts as a monostable multivibrator, triggered by the negative output pulse of the comparator.