<Li> 74 (HC / HCT) 7541 Octal Buffer with Schmitt Trigger Inputs and Three - State Noninverted Outputs </Li> <Li> SN74LV8151 is a 10 - bit universal Schmitt - trigger buffer with 3 - state outputs </Li> <P> A number of 4000 series devices include a Schmitt trigger on inputs, for example: </P> <Ul> <Li> 4017: Decade Counter with Decoded Outputs </Li> <Li> 4020: 14 - Stage Binary Ripple Counter </Li> <Li> 4022: Octal Counter with Decoded Outputs </Li> <Li> 4024: 7 - Stage Binary Ripple Counter </Li> <Li> 4040: 12 - Stage Binary Ripple Counter </Li> <Li> 4093: Quad 2 - Input NAND </Li> <Li> 40106: Hex Inverter </Li> <Li> 14538: Dual Monostable Multivibrator </Li> </Ul>

When is a trigger considered a positive trigger