46 MHz clock ceiling, 25 ns propagation delay — the timing budget anchor
The SN74HCT74PW is a dual D-type flip-flop from TI's 74HCT logic family, with set and reset inputs and complementary outputs. Its 46 MHz maximum clock frequency sets the upper data-rate limit for the flip-flop stage — above that the internal setup/hold window closes and the output becomes metastable. Propagation delay is 25 ns max at 5.5 V supply with a 50 pF load. That 25 ns is the time from clock edge to valid Q output; it adds directly to the combinational logic delay in the path, so the total timing budget for the downstream register must accommodate it.
Supply rails and temperature — 4.5-5.5 V, -40 to 85 °C
The supply voltage range is 4.5 V to 5.5 V — a tight 5 V ±10 % window. This is a 5 V-only part; it does not run at 3.3 V. The 74HCT family is TTL-compatible on the input thresholds, so it interfaces directly with 5 V TTL logic without external level translation. Operating temperature spans -40 °C to 85 °C (TA), the standard industrial range. The 14-TSSOP package (4.40 mm width, 0.173" body) is a fine-pitch surface-mount footprint — the 0.65 mm lead pitch demands careful solder-paste stencil design for reliable reflow.
Output drive and quiescent draw — 4 mA per pin, 4 µA idle
Each output sources or sinks 4 mA (I_OH / I_OL). That is enough to drive a single standard TTL load or a low-power LED, but not a high-fan-out bus. For heavier loads, buffer the output with a line driver or use a higher-drive logic family like 74LVC. Quiescent current is 4 µA typical — negligible in a battery-powered design that spends most of its time in static logic states. The input capacitance is 3 pF per pin, so the dynamic power scales with the switching frequency and the number of toggling inputs.