Two NAND gates are used in the configuration shown here to perform as a monostable triggered by the positive edge of the input signal. The time the output of the circuit remains “’1 " is about 0.7 x R x C [R in ohm and C in farad]. Other NAND gates can be used in the same configuration. If the input remains unconnected to any circuit when triggered off, the addition of a ground resistor is recommended to prevent unstable operation. The value may be in the range between 10 k ohm and 10 M ohm. A suitable value if the circuit is triggered from CMOS logic is 100 k ohm.
Two NAND Gates Monostable