View sy10-100el31 datasheet:

SY10EL31 D FLIP-FLOP SY100EL31 WITH SET AND RESET FINAL FEATURES DESCRIPTION 475ps propagation delay The SY10/100EL31 are D flip-flops with set and reset. The devices are functionally equivalent to the E131 2.8GHz toggle frequency devices, with higher performance capabilities. With Internal 75K? input pull-down resistors propagation delays and output transition times Available in 8-pin SOIC package significantly faster than the E131, the EL31 is ideally suited for those applications which require the ultimate in AC performance. Both the set and reset inputs are asynchronous, level triggered signals. Data enters the master portion of the flip-flop when the clock is LOW and is transferred to the slave, and thus the outputs, upon a positive transition of the clock. PI