In digital circuit design, why do some circuits need to be realized by several identical gates in series?
In addition to the required logical relationship, NAND gate has weak driving ability. Sometimes, in order to improve driving ability, NAND gate or even OC gate should be added for level conversion. In order to make the pulse better and avoid burr, we should add more gates or use gate circuits with Schmidt trigger for shaping. On the other hand, considering the timing, the gate circuit is delayed.