Converter

555 Timer AC-Coupled Sine To Square Wave Converter. An auxiliary output is available at the DISCHARGE pin. The edges of the output is adjusted with respect to the input signal (at the zero crossings), not to the level-shifted signal at the THRESHOLD and TRIGGER pins. The signal at those pins, aside from being level-shifted, is also time-shifted with respect to the input and output signals. This is because of the phase shift introduced by the coupling capacitor and the delay due to the timer's hysteresis (LTP at Vcc/3, UTP at 2Vcc/3).