TTP239

2016/3/7

Page 13 of 16

Version：1.1

Application circuit

SDO

SDA

TPQ3

TPQ2

VDD

VREG

TPQ4

TPQ5

SCL

TP0

TP1

TP2

TP3

TP4

TP5

TP6

TP7

TCP239

T6

T5

T4

T3

T2

T1

22

Cs3

K3

Cs2

K2

Cs1

K1

Cs0

K0

VDD

C1

104

21

20

19

18

17

16

15

14

23

24

25

26

27

28

29

30

31

32

1

8

7

6

5

4

3

2

13

12

11

10

9

ELECTRODE

Cs7

Cs6

Cs5

Cs4

K7

K6

K5

K4

P.S.：

1. On PCB, the length of lines from touch pad to IC pin shorter is better.

And the lines do not parallel and cross with other lines.

2. The power supply must be stable. If the supply voltage drift or shift quickly, maybe causing

sensitivity anomalies or false detections.

3. The material of panel covering on the PCB can not include the metal or the electric element.

The paints on the surfaces are the same.

4. The C1 capacitor must be used between VDD and VSS; and should be routed with very short

tracks to the device’s VDD and VSS pins (TTP239).

5. The capacitance Cs0~Cs7 can be used to adjust the sensitivity. The value of Cs0~Cs7 use

smaller, then the sensitivity will be better. The sensitivity adjustment must according to the

practical application on PCB. The range of Cs0~Cs7 value are 1~50pF.

6. The sensitivity adjustment capacitors（Cs0~Cs7）must use smaller temperature coefficient and

more stable capacitors. Such are X7R, NPO for example. So for touch application, recommend to

use NPO capacitor, for reducing that the temperature varies to affect sensitivity.

7. When the system doesn’t use the serial output interface for TTP239, the SCL pin of TTP239 must

be connected to VDD or VSS.