These devices may be used as a level converter for interfacing TTL or NMOS to High Speed CMOS. The inputs are compatible with TTL, NMOS and CMOS output voltage levels. The CK input is active on the rising edge. Both LOAD and CLR inputs are active on low logic level. Presetting of these IC's is synchronous to the rising edge of CK. The clear function of the TC74ACT163 is synchronous to CK, while the TC74ACT161 are cleared asynchronously. Two enable inputs (ENP and ENT) and CARRY OUTPUT are provided to enable easy cascading of counters, which facilitates easy implementation of n-bit counters without using external gates.