SCHMITT TRIGGERS in pakistanDUAL GATE/HEX INVERTER
The SN54LS/74LS13 and SN54LS/74LS14 contain logic gates / inverters
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. Additionally, they have greater noise
margin than conventional inverters.
Each circuit contains a Schmitt trigger followed by a Darlington level shifter
and a phase splitter driving a TTL totem pole output. The Schmitt 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
thresholds (typically 800 mV) is determined internally by resistor ratios and is
essentially insensitive to temperature and supply voltage variations.
