The HEF4027B is a dual positive-edge triggered JK flip-flop featuring independent set direct (nSD), clear direct (nCD), clock inputs (nCP) and complementary outputs (nQ and nQ). Data is accepted when nCP is LOW, and transferred to the output on the positive-going edge of the clock. The asynchronous clear-direct (nCD) and set-direct (nSD) are independent and override the nJ, nK, and nCP inputs. Schmitt-trigger action in the clock input makes the circuit highly tolerant to slower clock rise and fall times. Inputs include clamp diodes. This enables the use of current limiting resistors to interface inputs to voltages in excess of VDD.