Input buffer circuit with differential input thresholds operable with high common mode input voltages

摘要

An electrical input buffer circuit is provided for receiving an input signal such as an electronic spark timing signal and providing an output signal despite the presence of noise. The input buffer circuit receives a control signal and a reference voltage signal, and the voltage potential therebetween provides a differential input. A voltage divider network is coupled between the inputs for producing a first voltage potential and a second voltage potential in response to the differential input. A differential pair of NPN type transistors compares the control signal to a threshold value. The input buffer circuit produces an output high or low signal as a function of the input control voltage and is allowed to operate above and below local ground.