110 MHz D-type in a 16-pin DIP — what this part is for
The Texas Instruments SN74S175N is a quad D-type flip-flop from the 74S Schottky logic family, clocked at 110 MHz with a propagation delay of 12 ns at 5 V into 15 pF. Each of the four flip-flops shares a common clock and master reset, and outputs are complementary (Q and Q-bar). The 16-pin PDIP package suits through-hole assembly on legacy or low-volume boards where a socketed logic IC is preferred. Typical applications include register storage, shift registers, and synchronous counters in 5 V TTL systems — think industrial controllers, test equipment, or telecom line cards that still run on 74S glue logic.
110 MHz clock and 12 ns propagation — timing budget
The 12 ns max propagation delay (clock to Q, 15 pF load) sets the hold-time margin for the receiving register. The 96 mA quiescent supply current reflects the Schottky clamp speed.
Supply and output drive
The SN74S175N operates from a 4.75 V to 5.25 V supply — a narrow window that assumes a regulated 5 V rail. Output drive is asymmetric: 1 mA source, 20 mA sink. That's enough to drive one or two standard TTL loads directly, but for driving higher fan-out or long backplane traces, buffer the outputs. The complementary outputs give you both polarities without an external inverter, saving board space in counter and register applications.
For dual-sourcing, the SN74LS175NS (surface-mount, 40 MHz, lower power) is a functional alternative if your board can accommodate the slower speed and different package — but it is not pin-compatible in the same socket.