The SN74AS74AD is a dual positive-edge-triggered D-type flip-flop from Texas Instruments' 74AS series, with set and reset presets on each element. Each of the two flip-flops stores one bit, presenting complementary outputs (Q and Q̅) to the downstream logic.
Speed and propagation delay — timing margin for bus design
Maximum clock frequency is 105 MHz, which sets the upper limit for the data toggle rate. The max propagation delay is 9 ns at 5 V supply with a 50 pF load — this delay from clock edge to valid output is the timing budget the receiving device must accommodate. For a 105 MHz clock (period ~9.5 ns), the 9 ns propagation delay consumes nearly the entire cycle, so the part is best suited for moderate-speed bus applications where the clock-to-output delay is not the critical path.
Power budget and output drive capability
Output drive capability is asymmetric: 2 mA source (output high) and 20 mA sink (output low). The 20 mA sink current is sufficient to drive a standard TTL load or a low-power LED indicator, but the 2 mA source limit means the high-level output cannot drive heavy loads directly — a buffer or pull-up resistor may be needed for fan-out beyond a few gates.
Supply and temperature operating envelope
The 5 V supply is typical for legacy TTL and 74AS logic families.