The 7413 IC is composed of two independent Schmitt-Triggered 4-Input NAND gates. The general logical performance of these NAND gates resembles that of the 7400 or other NAND gates.The addition of the Schmitt Triggered circuitry affects the wave forms that are produced as an output. Schmitt Trigger Circuits are generally constructed from a comparator, but instead of the usual negative feedback, they implement a positive feedback mechanism. In the most simplest terms, Schmitt Trigger logic gates have a greater immunity to noise in the input lines. With noise suppression, the logic gates (in this case NANDs) are more likely to remain in their current state unless a true change to the input was intended. Glitches and high speed random noise in the lines is less likely to toggle the status of the output.
View Datasheet Immediately - CLICK HERE	Devices (7400 series) which include a Schmitt-Triggered Circuit: 7413: Dual Schmitt trigger 4-input NAND Gate 7414: Hex Schmitt trigger Inverter 7419: Hex Schmitt trigger Inverter 74121: Monostable Multivibrator with Schmitt Trigger Inputs 74132: Quad 2-input NAND Schmitt Trigger 74221: Dual Monostable Multivibrator with Schmitt Trigger Input 74232: Quad NOR Schmitt Trigger 74240: Octal Buffer with Schmitt Trigger Inputs and Three-State Inverted Outputs 74241: Octal Buffer with Schmitt Trigger Inputs and Three-State Noninverted Outputs 74244: Octal Buffer with Schmitt Trigger Inputs and Three-State Noninverted Outputs 74310: Octal Buffer with Schmitt Trigger Inputs 74540: Octal Buffer with Schmitt Trigger Inputs and Three-State Inverted Outputs 74541: Octal Buffer with Schmitt Trigger Inputs and Three-State Noninverted Outputs