74LS109 – Dual J-K Positive-edge-triggered Flip-Flops
This device contains two independent positive-edge-triggered J-K flip-flops with complementary outputs. The J and K data is accepted by the flip-flop on the rising edge of the clock pulse. The triggering occurs at a voltage level and is not directly related to the transition time of the rising edge of the clock. The data on the J and K inputs may be changed while the clock is HIGH or LOW as long as setup and hold times are not violated. A low logic level on the preset or clear inputs will set or reset the outputs regardless of the logic levels of the other inputs.
*Image shown is a representation only.