Abstract: A monostable multivibrator circuit is disclosed which uses a feedback diode to couple the output signal of the monostable back to one terminal of the timing capacitor and thereby maintain the voltage at this capacitor terminal at a constant level for a duration equal to the pulse duration of the monostable output. A transistorized internal combustion engine ignition system is illustrated which incorporates the diode feedback monostable circuit. A trigger input signal actuates a first transistor switch which creates an abrupt negative transition that is coupled across a timing capacitor and results in turning off a second transistor for a predetermined amount of time. A third transistor monitors and inverts the output of the second transistor and produces an output signal at its collector. This inverted output signal forms the output of the monostable multivibrator and this signal is fed back to one terminal of the timing capacitor by a feedback diode.