HCF4093 is a quad 2-input NAND schmitt trigger that features internal schmitt trigger action without the need for external components. Its characteristics include: 0.9V hysteresis voltage, noise immunity greater than 50% of VDD, no limit on input rise and fall times, quiescent current specified up to 20V, standardized symmetrical output characteristics, and parametric ratings of 5V, 10V, and 15V.