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.
Lifecycle and sourcing
The SN74S175N is listed as Active with ROHS3 compliance. 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.