Search results
Results from the WOW.Com Content Network
The Schmitt trigger was invented by American scientist Otto H. Schmitt in 1934 while he was a graduate student, [1] later described in his doctoral dissertation (1937) as a thermionic trigger. [2] It was a direct result of Schmitt's study of the neural impulse propagation in squid nerves.
The following is a list of CMOS 4000-series digital logic integrated circuits.In 1968, the original 4000-series was introduced by RCA.Although more recent parts are considerably faster, the 4000 devices operate over a wide power supply range (3V to 18V recommended range for "B" series) and are well suited to unregulated battery powered applications and interfacing with sensitive analogue ...
For CMOS (AC, HC, etc.) ... hex inverter gate Schmitt trigger 14 SN74LS19: 74x20 2 dual 4-input NAND gate 14 SN74LS20: 74x21 2 dual 4-input AND gate 14 SN74LS21:
A very early CD4029A counter IC, in 16-pin ceramic dual in-line package (DIP-16), manufactured by RCA Colorized IC die and schematics of CD4011BE NAND gateThe 4000 series was introduced as the CD4000 COS/MOS series in 1968 by RCA [1] as a lower power and more versatile alternative to the 7400 series of transistor-transistor logic (TTL) chips.
Typically, CMOS input thresholds require high-level signals to be at least 70% of Vcc and low-level signals to be at most 30% of Vcc. (TTL has the input high level above 2.0 V and the input low level below 0.8 V, so a TTL high-level signal could be in the forbidden middle range for 5 V CMOS.)
One of the issues with using an RC network to generate a PoR pulse is the sensitivity of the R and C values to the power-supply ramp characteristics. When the power supply ramp is rapid, the R and C values can be calculated so that the time to reach the switching threshold of the Schmitt trigger is enough to apply a long enough reset pulse.
Relaxation oscillators are generally used to produce low frequency signals for such applications as blinking lights and electronic beepers. During the vacuum tube era they were used as oscillators in electronic organs and horizontal deflection circuits and time bases for CRT oscilloscopes; one of the most common was the Miller integrator circuit invented by Alan Blumlein, which used vacuum ...
Schmitt trigger implemented by a non-inverting comparator. Another typical configuration of op amps is with positive feedback, which takes a fraction of the output signal back to the non-inverting input. An important application of positive feedback is the comparator with hysteresis, the Schmitt trigger.