TTP223 touch sensor board
TTP223 capacitive touch board · 2–5.5 V · push-pull output on I/O, active high, momentary · about 60 ms to respond · touch the pad (click and hold the board)
Try it on the benchThe lab drops it on an empty bench and opens its datasheet card.
Pins
- GND
- I/O
- VCC
What it is
The TTP223 is a one-key capacitive touch sensor. The touch electrode is on the back of the board. When a finger is near it, the I/O pin switches after about 60 ms. Its push-pull output can drive a microcontroller pin or a small transistor directly.
What to check before you buy or wire it
- Supply: 2–5.5 V. Keep fingers off the pad for the first half second after power-up, while the chip calibrates.
- Solder pad A sets the output: open is active high, bridged is active low. Solder pad B sets the mode: open is momentary, bridged makes each touch toggle the output.
Common mistakes
- Touching the pad while powering up, so the chip calibrates with a finger present and then reads backwards.
- Adding a pull-down or pull-up resistor: the output already drives both ways.
Where it is used
Touch buttons behind thin plastic or glass, lamp switches, and keyless panels.