DESCRIPTION
The 74F132 contains four 2-input NAND gates which accept
standard TTL input signals and provide standard TTL output levels.
They are capable of transforming slowly changing input signals into
sharply defined, jitter-free output signals. In addition, they have
greater noise margin than conventional NAND gates. Each circuit
contains a 2-input Schmitt trigger followed by a Darlington level
shifter and a phase splitter driving a TTL totem-pole output. The
Scmitt trigger uses positive feedback to effectively speed-up slow
input transitions and provide different input threshold voltages for
positive and negative-going transitions. This hysteresis between the
positive-going and negative-going input threshold (typically 800mV)
is determined by resistor ratios and is essentially insensitive to
temperature and supply voltage variations. As long as three inputs
remain at a more positive voltage than VT+MAX, the gate will
respond in the transition of the other input as shown in Waveform 1.