Texas Instruments 74HCT series, Logic Type NOR Gate, 4 Circuits, 2-Input, 4.5V ~ 5.5V Supply, -40°C ~ 85°C, Surface Mount, 14-TSSOP (0.173", 4.40mm Width).
| Parameter | Value |
|---|---|
| Series | 74HCT |
| Logic type | NOR Gate |
| Mounting | Surface Mount |
| Supply voltage | 4.5V ~ 5.5V |
| Current - quiescent | 2 µA |
| Current - output high, low | 4mA, 4mA |
| I/O channels | 2 |
| Operating temperature | -40°C ~ 85°C |
| Package | Tube |
| Case | 14-TSSOP (0.173\", 4.40mm Width) |
| Number of circuits | 4 |
| Input logic level - low | 0.8V |
| Input logic level - high | 2V |
| Max propagation delay @ v, max CL | 18ns @ 5.5V, 50pF |
The 14-TSSOP package is a fine-pitch surface-mount (0.173" body width, 4.40 mm), so you need a decent pair of tweezers and a steady hand for rework, but it is doable with a hot-air station. No lab bench required: if you have the footprint on the board, it swaps in the field with standard tools.
The maximum propagation delay is 18 ns at a 5.5V supply with a 50 pF load. That is the worst-case figure across temperature and voltage; typical delays are lower.
It is a quad 2-input NOR gate. Each of the four independent gates performs the NOR logic function: output is high only when both inputs are low. Typical use is inverting or combining digital signals in 5V logic systems.
The SN74HCT02PW uses HCT logic (TTL-compatible input thresholds: 0.8V low, 2V high), while the SN74HC02PW uses HC logic (CMOS thresholds: roughly 1.5V at 5V supply). If your input signal comes from a 3.3V microcontroller, the HCT version switches more reliably on a 5V rail because its lower threshold matches TTL levels. Both are quad 2-input NOR gates in the same 14-TSSOP package.