74hc series logic nxp phs74hc74d 652 the nxp 74hchct74 is a high speed is gate cmos device and is pin compatible with low power schottky ttl lsttl they are specified in compliance with jedec standard no 7a the 74hchct74 are dual positive edge triggered d type flip flops with individual data d inputs clock cp inputs set sd and reset rd inputs also complementary q and q outputs the set and reset are asynchronous active low inputs and operate independently of the clock input