Pin Configuration:
Figure 1: Pin Diagram Of WTC1008BSI
Definitions of Pins:
| Pin No. | Pin Name | Usage | Function Description |
| 1 | SW7 | | | Interface of touch key 7 (sense element 7) |
| 2 | SW6 | | | Interface of touch key 6 (sense element 6) |
| 3 | SW5 | | | Interface of touch key 5 (sense element 5) |
| 4 | SW4 | | | Interface of touch key 4 (sense element 4) |
| 5 | SW3 | | | Interface of touch key 3 (sense element 3) |
| 6 | SW2 | | | Interface of touch key 2 (sense element 2) |
| 7 | SW1 | | | Interface of touch key 1 (sense element 1 |
| 8 | SW0 | | | Interface of touch key 0 (sense element 0) |
9
| CSEL | | | Capacitor interface for adjusting the sensitivity |
| 10 | GND | | | Power ground |
| 11 | TS | | | Internal test foot, usually fixed with VCC |
| 12 | HLS | | | The selection of the initial electrical level on the state output: the initial state of connecting VCC output is high impedance, and the initial of connecting GND output is low |
| 13 | OUT0 | O | SW0 status output |
| 14 | OUT1 | O | SW1 status output |
| 15 | OUT2 | O | SW2 status output |
| 16 | OUT3 | O | SW3 status output |
17
| /RST | | | IC reset pin |
| 18 | VCC | | | Power input |
| 19 | OUT4 | O | SW4 status output |
| 20 | OUT5 | O | SW5 status output |
| 21 | OUT6 | O | SW6 status output |
| 22 | OUT7 | O | SW7 status output |
| 23 | BUZZ | O | Buzzer control pin |
| 24 | BLC | O | Backlight LED control pin |
Output Display:
When the effective touch occurred on the sensor disc is detected, the WTC1008BSI outputs the state of the sensing disk channel being touched in in 100ms, so that the user MCU can process it or directly drive to perform the circuit work. WTC1008BSI has two types of output. Select by HLS food of 1C connecting GND of VCC.
The output indication when HLS is connecting VCC.
Figure 2: The sequence diagram when HLS is connecting VCC
The output indication when HLS is connecting GND
Figure 2：The sequence diagram when HLS is connecting GND
Peripheral Circuit and Precautions:
The peripheral circuit of WTC1008BSI is very simple, and only needs a few resistors and capacitors. The key component is capacitor CSEL for adjusting the sensitivity and IK resistance group for measuring the matched impedance of circuit. CSEL should use 10%-precision polyester capacitor, capacitor made of NOP material or capacitor made of X7R material . 1K resistance group can provide you with the best and most stable measurement effect, and CSEL and matched resistance shall be placed as close as possible to IC at PCB layout.
Figure 4 is the application circuit diagram of WTC1008BSI working under the 8 key mode
Figure 4: WTC1008BSI Application Schematic Diagram