TTP226 8-channel touch sensor: specs and pinout
An eight-pad capacitive touch module built around a TonTek TTP226-series touch pad detector IC. It replaces eight push buttons with touch pads.
Specs
| Spec | Value | Source |
|---|---|---|
| Operating voltage VDD | 2.0 V min, 3 V typ, 5.5 V max (TTP226-809SN) | source Electrical characteristics (p.5) |
| Absolute maximum VDD | VSS - 0.3 V to VSS + 5.5 V | source Absolute maximum ratings (p.5) |
| Absolute maximum input voltage | VSS - 0.3 V to VDD + 0.3 V | source Absolute maximum ratings (p.5) |
| Operating temperature | -20 C to +70 C | source Absolute maximum ratings (p.5) |
| Touch inputs and outputs | 8 key inputs (I0 to I7), 8 outputs (Q0 to Q7) | source Pin table (p.4) |
| Output mode | Direct, matrix or serial, selected by pin options | source Features (p.1) |
Power
| Value | Source | |
|---|---|---|
| Supply | 2.0-5.5 V (chip, TTP226-809SN) | source Electrical characteristics (p.5) |
Chip pins
These are the pins of the chip on the module, from the chip datasheet. The module's own header may label or expose them differently.
The pin list is for the 28-pin SSOP TTP226-809SN IC; the page does not know that the module uses this exact variant. Pin numbers were checked against both the pin table (p.4) and the application diagrams (pp.10-12). The module board's header order, option jumpers and regulator are not covered by an official document.
| Pin | Function | Voltage | Notes | Source |
|---|---|---|---|---|
| 1 OSC2/TOPAD | Oscillator pin and internal common point of the sensor (I/O) | source Pin definition table (p.4); application diagram (p.10) | ||
| 2 I7 | Key (touch pad) input I7 | source Pin definition table (p.4); application diagram (p.10) | ||
| 3 I6 | Key (touch pad) input I6 | source Pin definition table (p.4); application diagram (p.10) | ||
| 4 I5 | Key (touch pad) input I5 | source Pin definition table (p.4); application diagram (p.10) | ||
| 5 I4 | Key (touch pad) input I4 | source Pin definition table (p.4); application diagram (p.10) | ||
| 6 I3 | Key (touch pad) input I3 | source Pin definition table (p.4); application diagram (p.10) | ||
| 7 I2 | Key (touch pad) input I2 | source Pin definition table (p.4); application diagram (p.10) | ||
| 8 I1 | Key (touch pad) input I1 | source Pin definition table (p.4); application diagram (p.10) | ||
| 9 I0 | Key (touch pad) input I0 | source Pin definition table (p.4); application diagram (p.10) | ||
| 10 OSC1 | System oscillator pin (I/O) | source Pin definition table (p.4); application diagram (p.10) | ||
| 11 VSS | Negative supply, ground | source Pin definition table (p.4); application diagram (p.10) | ||
| 12 VDD | Positive supply | source Pin definition table (p.4); application diagram (p.10) | ||
| 13 OPS1 | Output type option input with pull-high | source Pin definition table (p.4); application diagram (p.10) | ||
| 14 OPS0 | Output type option input with pull-high | source Pin definition table (p.4); application diagram (p.10) | ||
| 15 AHL | Option input with pull-high: selects active-high or active-low outputs | source Pin definition table (p.4); application diagram (p.10) | ||
| 16 Q0 | Output in direct mode | Also DO (serial shift-out) and SCN0 (first scan pin in matrix mode). | source Pin definition table (p.4); application diagram (p.10) | |
| 17 Q1 | Output in direct mode | Also SCN1 in matrix mode. | source Pin definition table (p.4); application diagram (p.10) | |
| 18 Q2 | Output in direct mode | Also SCN2 in matrix mode. | source Pin definition table (p.4); application diagram (p.10) | |
| 19 Q3 | Output in direct mode | Also SCN3 in matrix mode. | source Pin definition table (p.4); application diagram (p.10) | |
| 20 Q4 | Output in direct mode | Also SCN4 in matrix mode. | source Pin definition table (p.4); application diagram (p.10) | |
| 21 Q5 | Output in direct mode | Also SCN5 in matrix mode. | source Pin definition table (p.4); application diagram (p.10) | |
| 22 Q6 | Output in direct mode | Also RST (reset input) in serial mode. | source Pin definition table (p.4); application diagram (p.10) | |
| 23 Q7 | Output in direct mode | Also CK (clock input) in serial mode. | source Pin definition table (p.4); application diagram (p.10) | |
| 24 DV | Data-valid output signal | source Pin definition table (p.4); application diagram (p.10) | ||
| 25 SLSE1 | Sensitivity option input with pull-high | source Pin definition table (p.4); application diagram (p.10) | ||
| 26 SLSE2 | Sensitivity option input with pull-high | source Pin definition table (p.4); application diagram (p.10) | ||
| 27 SLSE3 | Sensitivity option input with pull-high | source Pin definition table (p.4); application diagram (p.10) | ||
| 28 SLSE4 | Sensitivity option input with pull-high | source Pin definition table (p.4); application diagram (p.10) |
Build with it
Project ideas for the TTP226 8-channel touch sensor. Each link opens Soldr with the prompt filled in; Soldr assigns the pins, checks power and shows how to wire every part.
- Eight-key touch pad with LEDs: Each of the 8 pads has its own output in direct mode, so the ESP32 can read 8 inputs. Power the module from 3.3 V (chip range 2.0-5.5 V) so its outputs sit at 3.3 V logic; check your module's output polarity.
- A touch scene selector with an ESP32, a TTP226 touch sensor module and a 0.96 inch OLED: Eight pads pick one of eight named scenes shown on the OLED. Low-voltage learning project.
- Eight-note touch instrument: Each pad plays one note on the passive buzzer, which needs a square wave from the ESP32.
Common mistakes
- Exceeding the supply limit: the absolute maximum is VSS + 5.5 V, so do not feed the bare chip more than 5.5 V (source: link, p.5)
- Driving the chip pins above VDD + 0.3 V: the input absolute maximum is VDD + 0.3 V (source: link, p.5)
- Assuming the module's IC is the exact part on this sheet: the sheet is for the TTP226-809SN variant, and the module's chip marking is not covered (source: link, first page)
Not covered by the official source
- Only a Chinese-language maker sheet for the TTP226-809SN variant was found; only numbers and pin names were taken from it.
- Elecrow-hosted copy for the plain TTP226 was not found at the guessed addresses.
- Operating current figures were not read reliably and are not given.
- Module option settings, header and regulator are not covered by an official document.
Sources
- link (TonTek TTP226-809SN datasheet, Ver 1.0, 2016/01/18, Chinese-language; copy hosted by LCSC)