TTP223 touch sensor: specs
A one-key capacitive touch module built around the Tontek TTP223 touch detector IC. It replaces a push button with a touch pad.
Specs
| Spec | Value | Source |
|---|---|---|
| Operating voltage | 2.0 V to 5.5 V | source Features (p.1); DC/AC Characteristics (p.3) |
| Operating current (3 V, no load) | 1.5 uA typical (3.0 uA max) low-power mode, SLRFTB=1; 3.5 uA typical (7.0 uA max) fast mode | source Features (p.1) |
| Response time | max about 60 ms fast mode; 220 ms low-power mode (3 V) | source Features (p.1); p.3 |
| Operating temperature | -20 C to +70 C | source Absolute Maximum Ratings (p.3) |
| Output drive (3 V) | 8 mA sink, -4 mA source | source DC/AC Characteristics (p.3) |
| Power-on stable time | about 0.5 s with the key disabled; no touch during this time | source Features (p.1) |
| Auto calibration | recalibrates about every 4.0 s when not touched | source Features (p.1) |
Power
| Value | Source | |
|---|---|---|
| Supply | 2.0 V to 5.5 V (chip) | source Features (p.1) |
| Current | 1.5 uA to 6.5 uA depending on mode (3 V, no load) | source Features (p.1) |
Pinout
We don't publish a pin table for this part: no official source we could verify gives one. Check the labels printed on your module, and see the notes below.
The Tontek sheet describes the bare IC with 11 pads (Q, OPDO, VSS, LPMB, TOG, VDD, AHLB, RST, SLRFTB, MOTB, I). The module board's header order, option jumpers (toggle/direct, active-high/low) and regulator are not covered by an official document, so no pin table is given.
Build with it
Project ideas for the TTP223 touch sensor. Each link opens Soldr with the prompt filled in; Soldr assigns the pins, checks power and shows how to wire every part.
- Touch doorbell: The chip works from 2.0 to 5.5 V, so it runs from 3.3 V. Its output can source 4 mA at 3 V, enough for a logic input.
- Touch-to-open flap: Power the servo from a separate 5 V supply with grounds joined, not from the board pin.
- Tap counter display: Response time is under 60 ms in fast mode, so quick taps register. The module may be set to toggle mode, which changes how taps count.
- Touch light demo: The LED needs a series resistor; the chip output sources up to 4 mA at 3 V.
Common mistakes
- Do not touch the pad for about 0.5 s after power-on; the chip is calibrating and ignores the key (source: link, Features, p.1).
- Sensitivity depends on the electrode size, panel thickness and the capacitance of the trace; a thicker cover reduces it (source: link, Function Description 1, p.4).
- The chip has an optional maximum-on time of 100 s (pad option MOTB); a module wired that way releases the output after 100 s of touch (source: link, Features, p.1).
Not covered by the official source
- Module board not documented by an official source, pin table omitted.
- Sheet is marked Preliminary.
Sources
- link (TTP223 1 Key Touch Pad Detector IC, Ver 1.0, 2008; Tontek)