ETC TS20

TS20
20-Ch Auto Sensitivity Calibration Capacitive Touch Sensor
SPECIFICATION V1.3
March 2009
ADSemiconductor
ADSemiconductor®
TS20 (20-CH Auto Sensitivity Calibration Capacitive Touch Sensor)
1 Specification
1.1 General Feature
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20-Channel capacitive sensor with auto sensitivity calibration
2
I C serial interface
Selectable output operation (single mode / multi-mode)
Independently adjustable in 16 steps (2 mode) sensitivity
Adjustable response time by the control registers
Embedded common and normal noise elimination circuit
Available LED PWM drive ports up to 20 channels
Controllable LED luminance
Available tact switch input up to 20 channels
SLEEP mode to save the current consumption
RoHS compliant 28QFN and 28TSSOP package
1.2

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
Application
Mobile application (mobile phone, PDA, PMP, MP3, Car navigation)
Membrane switch replacement
Sealed control panels, keypads
Door key-lock matrix application
Touch screen replacement application
1.3 Package (28 QFN / 28TSSOP)
CS20
24
INT
25
VDD
26
SDA
27
SCL
VSS
ADD
28
23
22
CS5
1
28
CS4
CS6
2
27
CS3
CS7
3
26
CS2
VSS
4
25
CS1
21
CS19
CS2
2
20
CS18
CS8
5
24
ADD
CS3
3
19
CS17
CS9
6
23
VSS
CS4
4
18
CS16
CS10
7
22
SCL
CS5
8
21
SDA
17
CS15
CS11
5
CS12
9
20
VDD
CS6
6
16
CS14
VSS
10
19
INT
CS7
7
15
CS13
CS13
11
18
CS20
CS14
12
17
CS19
CS15
13
16
CS18
CS16
14
15
CS17
8
9
10
11
12
13
14
VSS
CS12
CS11
CS10
CS9
CS8
VSS
TS20 (28QFN)
ADS
TS20
1
ADS
TS20
CS1
TS20 (28TSSOP)
※ Drawings not to scale
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ADSemiconductor®
TS20 (20-CH Auto Sensitivity Calibration Capacitive Touch Sensor)
2 Pin Description
2.1 TS20 (28QFN package)
PIN No.
Name
I/O
1
CS1
Analog Input
/Digital Output
2
CS2
Analog Input
/Digital Output
3
CS3
Analog Input
/Digital Output
4
CS4
Analog Input
/Digital Output
5
CS5
Analog Input
/Digital Output
6
CS6
Analog Input
/Digital Output
7
CS7
Analog Input
/Digital Output
8
VSS
Ground
9
CS8
Analog Input
/Digital Output
10
CS9
Analog Input
/Digital Output
11
CS10
Analog Input
/Digital Output
12
CS11
Analog Input
/Digital Output
13
CS12
Analog Input
/Digital Output
14
VSS
Ground
15
CS13
Analog Input
/Digital Output
16
CS14
Analog Input
/Digital Output
Description
CH1 capacitive sensor input
CH1 Tact switch input [Note 2]
CH1 LED Drive output (Open drain) [Note 3]
CH2 capacitive sensor input
CH2 Tact switch input [Note 2]
CH2 LED Drive output (Open drain) [Note 3]
CH3 capacitive sensor input
CH3 Tact switch input [Note 2]
CH3 LED Drive output (Open drain) [Note 3]
CH4 capacitive sensor input
CH4 Tact switch input [Note 2]
CH4 LED Drive output (Open drain) [Note 3]
CH5 capacitive sensor input
CH5 Tact switch input [Note 2]
CH5 LED Drive output (Open drain) [Note 3]
CH6 capacitive sensor input
CH6 Tact switch input [Note 2]
CH6 LED Drive output (Open drain) [Note 3]
CH7 capacitive sensor input
CH7 Tact switch input [Note 2]
CH7 LED Drive output (Open drain) [Note 3]
Supply ground
CH8 capacitive sensor input
CH8 Tact switch input [Note 2]
CH8 LED Drive output (Open drain) [Note 3]
CH9 capacitive sensor input
CH9 Tact switch input [Note 2]
CH9 LED Drive output (Open drain) [Note 3]
CH10 capacitive sensor input
CH10 Tact switch input [Note 2]
CH10 LED Drive output (Open drain) [Note 3]
CH11 capacitive sensor input
CH11 Tact switch input [Note 2]
CH11 LED Drive output (Open drain) [Note 3]
CH12 capacitive sensor input
CH12 Tact switch input [Note 2]
CH12 LED Drive output (Open drain) [Note 3]
Supply ground
CH13 capacitive sensor input
CH13 Tact switch input [Note 2]
CH13 LED Drive output (Open drain) [Note 3]
CH14 capacitive sensor input
CH14 Tact switch input [Note 2]
CH14 LED Drive output (Open drain) [Note 3]
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Protection
VDD/GND
VDD/GND
VDD/GND
VDD/GND
VDD/GND
VDD/GND
VDD/GND
VDD
VDD/GND
VDD/GND
VDD/GND
VDD/GND
VDD/GND
VDD
VDD/GND
VDD/GND
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ADSemiconductor®
TS20 (20-CH Auto Sensitivity Calibration Capacitive Touch Sensor)
17
18
19
20
21
22
CS15
CS16
CS17
CS18
CS19
CS20
23
24
INT
VDD
25
SDA
26
27
28
SCL
VSS
ADD
Analog Input
/Digital Output
Analog Input
/Digital Output
Analog Input
/Digital Output
Analog Input
/Digital Output
Analog Input
/Digital Output
Analog Input
/Digital Output
Digital Output
Power
Digital
Input/Output
Digital Input
Ground
Digital Input
CH15 capacitive sensor input
CH15 Tact switch input [Note 2]
CH15 LED Drive output (Open drain)
CH16 capacitive sensor input
CH16 Tact switch input [Note 2]
CH16 LED Drive output (Open drain)
CH17 capacitive sensor input
CH17 Tact switch input [Note 2]
CH17 LED Drive output (Open drain)
CH18 capacitive sensor input
CH18 Tact switch input [Note 2]
CH18 LED Drive output (Open drain)
CH19 capacitive sensor input
CH19 Tact switch input [Note 2]
CH19 LED Drive output (Open drain)
CH20 capacitive sensor input
CH20 Tact switch input [Note 2]
CH20 LED Drive output (Open drain)
Interrupt output (Open drain)
Power (2.5V~5.0V)
VDD/GND
[Note 3]
VDD/GND
[Note 3]
VDD/GND
[Note 3]
VDD/GND
[Note 3]
VDD/GND
[Note 3]
VDD/GND
[Note 3]
VDD/GND
GND
2
VDD/GND
2
VDD/GND
VDD
VDD/GND
I C data (Open drain)
I C clock input
Supply ground
2
I C slave ID selection input [Note 1]
Note 1:
Refer to chapter 7. I2C Interface.
Refer to chapter 6.2 CS implementation for Tact switch input.
Note 3: Refer to chapter 6.3 CS implementation for LED drive output.
Note 2:
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ADSemiconductor®
TS20 (20-CH Auto Sensitivity Calibration Capacitive Touch Sensor)
2.2 TS20 (28TSSOP package)
PIN No.
Name
I/O
1
CS5
Analog Input
/Digital Output
2
CS6
Analog Input
/Digital Output
3
CS7
Analog Input
/Digital Output
4
VSS
Ground
5
CS8
Analog Input
/Digital Output
6
CS9
Analog Input
/Digital Output
7
CS10
Analog Input
/Digital Output
8
CS11
Analog Input
/Digital Output
9
CS12
Analog Input
/Digital Output
10
VSS
Ground
11
CS13
Analog Input
/Digital Output
12
CS14
Analog Input
/Digital Output
13
CS15
Analog Input
/Digital Output
14
CS16
Analog Input
/Digital Output
15
CS17
Analog Input
/Digital Output
16
CS18
Analog Input
/Digital Output
Description
CH5
CH5
CH5
CH6
CH6
CH6
CH7
CH7
CH7
capacitive sensor input
Tact switch input [Note 2]
LED Drive output (Open drain) [Note 3]
capacitive sensor input
Tact switch input [Note 2]
LED Drive output (Open drain) [Note 3]
capacitive sensor input
Tact switch input [Note 2]
LED Drive output (Open drain) [Note 3]
Supply ground
Protection
VDD/GND
VDD/GND
VDD/GND
VDD
CH8 capacitive sensor input
CH8 Tact switch input [Note 2]
CH8 LED Drive output (Open drain) [Note 3]
CH9 capacitive sensor input
CH9 Tact switch input [Note 2]
CH9 LED Drive output (Open drain) [Note 3]
CH10 capacitive sensor input
CH10 Tact switch input [Note 2]
CH10 LED Drive output (Open drain) [Note 3]
CH11 capacitive sensor input
CH11 Tact switch input [Note 2]
CH11 LED Drive output (Open drain) [Note 3]
CH12 capacitive sensor input
CH12 Tact switch input [Note 2]
CH12 LED Drive output (Open drain) [Note 3]
Supply ground
CH13 capacitive sensor input
CH13 Tact switch input [Note 2]
CH13 LED Drive output (Open drain) [Note 3]
CH14 capacitive sensor input
CH14 Tact switch input [Note 2]
CH14 LED Drive output (Open drain) [Note 3]
CH15 capacitive sensor input
CH15 Tact switch input [Note 2]
CH15 LED Drive output (Open drain) [Note 3]
CH16 capacitive sensor input
CH16 Tact switch input [Note 2]
CH16 LED Drive output (Open drain) [Note 3]
CH17 capacitive sensor input
CH17 Tact switch input [Note 2]
CH17 LED Drive output (Open drain) [Note 3]
CH18 capacitive sensor input
CH18 Tact switch input [Note 2]
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VDD/GND
VDD/GND
VDD/GND
VDD/GND
VDD/GND
VDD
VDD/GND
VDD/GND
VDD/GND
VDD/GND
VDD/GND
VDD/GND
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ADSemiconductor®
TS20 (20-CH Auto Sensitivity Calibration Capacitive Touch Sensor)
CH18 LED Drive output (Open drain) [Note 3]
CH19
CH19
CH19
CH20
CH20
CH20
capacitive sensor input
Tact switch input [Note 2]
LED Drive output (Open drain) [Note 3]
capacitive sensor input
Tact switch input [Note 2]
LED Drive output (Open drain) [Note 3]
17
CS19
Analog Input
/Digital Output
18
CS20
Analog Input
/Digital Output
19
INT
Digital Output
20
VDD
Power
21
SDA
Digital
Input/Output
I C data (Open drain)
22
SCL
Digital Input
23
24
VSS
ADD
Ground
Digital Input
25
CS1
Analog Input
/Digital Output
26
CS2
Analog Input
/Digital Output
27
CS3
Analog Input
/Digital Output
28
CS4
Analog Input
/Digital Output
Interrupt output (Open drain)
Power (2.5V~5.0V)
VDD/GND
VDD/GND
VDD/GND
GND
2
VDD/GND
I C clock input
2
VDD/GND
Supply ground
2
I C slave ID selection input [Note 1]
CH1 capacitive sensor input
CH1 Tact switch input [Note 2]
CH1 LED Drive output (Open drain) [Note 3]
CH2 capacitive sensor input
CH2 Tact switch input [Note 2]
CH2 LED Drive output (Open drain) [Note 3]
CH3 capacitive sensor input
CH3 Tact switch input [Note 2]
CH3 LED Drive output (Open drain) [Note 3]
CH4 capacitive sensor input
CH4 Tact switch input [Note 2]
CH4 LED Drive output (Open drain) [Note 3]
VDD
VDD/GND
VDD/GND
VDD/GND
VDD/GND
VDD/GND
Note 1:
Refer to chapter 7. I2C Interface.
Note 2: Refer to chapter 6.2 CS implementation for Tact switch input.
Note 3: Refer to chapter 6.3 CS implementation for LED drive output.
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TS20 (20-CH Auto Sensitivity Calibration Capacitive Touch Sensor)
3 Absolute Maximum Rating
Maximum supply voltage
5.5V
Maximum voltage on any pin VDD+0.3
Maximum current on any PAD 100mA
Power Dissipation
800mW
Storage Temperature
-50 ~ 150℃
Operating Temperature
-20 ~ 75℃
Junction Temperature
150℃
Note Unless any other command is noted, all above are operated in normal temperature.
4 ESD & Latch-up Characteristics
4.1 ESD Characteristics
Mode
H.B.M
M.M
C.D.M
Polarity
Minimum Level
Reference
8000V
VDD
8000V
GND
8000V
P to P
625V
VDD
625V
GND
500V
P to P
1000V
Field Induced Charge
Polarity
Minimum Level
Reference
Positive
100mA
Negative
-100mA
Positive
8.0V
Pos / Neg
Pos / Neg
-
4.2 Latch-up Characteristics
Mode
I Test
V supply over 5.0V
JESD78A
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TS20 (20-CH Auto Sensitivity Calibration Capacitive Touch Sensor)
5 Electrical Characteristics
▪ VDD=3.3V,
TA = 27℃
Characteristics
Operating supply voltage
Symbol
VDD
Test Condition
VDD=
VDD=
VDD=
Normal mode
VDD=
VDD=
Fast mode
VDD=
VDD=
Sleep mode
VDD=
VDD= 3.3V (2M Bps)
VDD= 5.0V (2M Bps)
Slow mode
Current consumption
IDD
[Note4]
IDD_I2C
Digital output maximum
sink current
LED drive output sink
current per 1channel
LED drive output total
sink current
Tact switch interface input
internal pull-up current
Start supply voltage for
internal reset
Sense input
capacitance range [Note5]
Minimum detective
capacitance difference
Output impedance
(open drain)
3.3V
5.0V
3.3V
5.0V
3.3V
5.0V
3.3V
5.0V
Min
2.5
-
Max
5.0
180
240
2.2
3.4
Units
V
-
Typ
3.3
85
120
130
180
190
250
9
11
1.8
2.8
㎂
㎃
IOUT
TA = 25℃ (Normal I2C Output)
-
-
4.0
㎃
ILED_OUT
TA = 25℃ (LED Drive Output)
-
-
8.0
㎃
ILED_TOT
TA = 25℃ (LED Drive Output)
-
-
30.0
㎃
VDD= 5.0V, TA = 25℃
-
5.6
-
㎂
TA = 25℃
-
-
0.3∙VDD
V
CS
-
-
50
㎊
ΔCMIN
0.1
-
-
㎊
ΔC > ΔCMIN
-
12
-
ΔC < ΔCMIN
-
30M
100
80
60
-
-
200
1000
Ω
2.5
0
-
1
usec
usec
100
-
-
msec
ITACT
VDD_RST
Zo
Self calibration time after
system reset
TCAL
Sense input resistance
RS
Internal reset pulse duration
TRST
SCL, SDA rising delay
Minimum power on
SCL, SDA high time
TSCL, TSDA
TH_SCL,
TH_SDA
Slow calibration speed
Normal calibration speed
Fast calibration speed
-
Ω
ms
Note 4 : Maximum communication speed is 2Mbps.
Note 5 : The sensitivity can be decreased with higher parallel capacitance of CS pin including parasitic capacitance
made by neighbor GND or other pattern. The series resistor(under 1kΩ) of CS can be used in noisy condition to avoid
mal-function from external surge and ESD.
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TS20 (20-CH Auto Sensitivity Calibration Capacitive Touch Sensor)
6 Implementation of TS20
6.1 CS implementation
TS20 has 2 sensitivity modes and each mode has 16 step selections of the sensitivity. And
Sensitivity of each sensing channel (CS) can be independently controlled by TS20 Control
Register (I2C interface). External components of CS pin such as series resistor or parallel
capacitor isn’t necessary. The parallel parasitic capacitance of CS pins caused by touch line,
touch pad and adjacent GND or other pattern may affect sensitivity. The sensitivity will be
decreased when bigger parallel parasitic capacitance of CS pin is added.
Sensitivity mediation is required to complement sensitivity difference between channels. Parallel
capacitor (CS1~S20) of CS pin is useful in case of detail sensitivity mediation. The sensitivity
would be increased when smaller value of CS is used. Under 50pF capacitor can be used as
sensitivity meditation capacitor and a few pF is usually used. The RS, serial connection resistor
of CS pins, may be used to avoid mal-function from external surge and ESD. (It might be
optional.) From 200Ω to 1kΩ is recommended for RS. Refer to below CS pins application figure.
RS20
CS20 <<
Touch PAD20
CS20
RS1
CS1 <<
Touch PAD1
CS1
The TS20 has twenty independent touch sensor inputs from CS1 to CS20. The internal touch
decision process of each channel is separated from others. Therefore twenty channel touch key
board application can be designed by using only one TS20 without coupling problems.
The size and shape of PAD might have influence on the sensitivity. The sensitivity will be optimal
when the size of PAD is approximately an half of the first knuckle (it’s about 10 ㎜ｘ 7 ㎜). The
connection line of CS to touch PAD is recommended to be routed as short as possible to
prevent from abnormal touch detect caused by connection line.
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ADSemiconductor®
TS20 (20-CH Auto Sensitivity Calibration Capacitive Touch Sensor)
6.2 CS implementation for tact switch input
CS1~CS20
<<
Tact Input
Tact Switch
1
CS input ports are possible to change to tact switch input by setting the Port Control Register
through I2C interface. The number of possible tact switch input is 20. And user can get the
output data from output registers (Chapter 8.9). When the CS is used for tact switch input, the
internal pull-up current source makes it possible without external pull-up resistors. Typical
internal pull-up current is 5.6uA independent to external condition
6.3 CS implementation for LED drive output
VDD
RLED
LED
CS1~CS20
>>
LED drive output
2
CS input ports are possible to change to LED drive output by setting the Port Control Register
through I2C interface. The number of possible LED drive output channel is 20. Each channel
has 16 steps of LED dimming. Each LED dimming step is controlled by setting Port Control
2
Register through I C interface. The maximum current that is sunk by CS is 8mA when the CS is
used for LED drive output port.
1
2
Refer to chapter 8.6 Port Control Register
Refer to chapter 8.6 Port Control Register
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TS20 (20-CH Auto Sensitivity Calibration Capacitive Touch Sensor)
6.4 Internal reset operation
The TS20 has stable internal reset circuit to offer reset pulse to digital block. The supply voltage
for a system start or restart should be under 0.3∙VDD of normal operation VDD. No external
components required for TS20 power reset, that helps simple circuit design and to realize the
low cost application.
6.5 Power on sequence for SCL & SDA
Items
Description
min
typ
max
unit
TSCL
Settling time for SCL voltage rising to 0.8 VDD
0
-
1.0
usec
TSDA
Settling time for SDA voltage rising to 0.8 VDD
0
-
1.0
usec
TH_SCL, TH_SDA
SCL SDA high pulse remain time for power on
100
-
-
msec
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TS20 (20-CH Auto Sensitivity Calibration Capacitive Touch Sensor)
7 I2C Interface
7.1
I2C Enable / Disable
If the SDA or SCL signal goes to low, I2C control block is enabled automatically. And if
the SDA and SCL signal maintain high during about 2 us, I2C control block is disabled
automatically also.
7.2
Start & Stop Condition
 Start Condition (S)
 Stop Condition (P)
 Repeated Start (Sr)
7.3 Data validity
The SDA should be stable when the SCL is high and the SDA can be changed when the SCL is
low.
7.4 Byte Format
The byte structure is composed with 8Bit data and an acknowledge signal.
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TS20 (20-CH Auto Sensitivity Calibration Capacitive Touch Sensor)
7.5 Acknowledge
It is a check bit whether the receiver gets the data from the transmitter without error or not. The
receiver will write ‘0’ when it received the data successfully and ‘1’ if not.
7.6 First Byte
7.6.1 Slave Address
It is the first byte from the start condition. It is used to access the slave device.
TS20 Chip Address : 7bit
ADD
Address
GND
VDD
0xD4
0xF4
─
7.6.2 R/W
The direction of data is decided by the bit and it follows the address data.
MSB
Address
LSB
R/W
7 bit
1bit
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TS20 (20-CH Auto Sensitivity Calibration Capacitive Touch Sensor)
7.7 Transferring Data
7.7.1 Write Operation
The byte sequence is as follows:
■ the first byte gives the device address plus the direction bit (R/W = 0).
■ the second byte contains the internal address of the first register to be accessed.
■ the next byte is written in the internal register. Following bytes are written in successive
internal registers.
■ the transfer lasts until stop conditions are encountered.
■ the TS20 acknowledges every byte transfer.
7.7.2 Read Operation
The address of the first register to read is programmed in a write operation without data, and
terminated by the stop condition. Then, another start is followed by the device address and
R/W= 1. All following bytes are now data to be read at successive positions starting from the
initial address.
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TS20 (20-CH Auto Sensitivity Calibration Capacitive Touch Sensor)
7.7.3 Read/Write Operation
7.8 I2C write and read operations in normal mode
2
The following figure represents the I C normal mode write and read registers.
☞ Write register 0x00 to 0x01 with data AA and BB
Start
Device
Address 0xD4
ACK
Register
Address 0x00
ACK
Data AA
ACK
Data BB
ACK
Stop
Read register 0x00 and 0x01
Start
Device
Address 0xD4
ACK
Register
Address 0x00
ACK
Start
Device
Address 0xD5
ACK
Data Read AA
ACK
From Master to Slave
Stop
Data Read BB
ACK
Stop
From Slave to Master
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TS20 (20-CH Auto Sensitivity Calibration Capacitive Touch Sensor)
8 TS20 Control Register List
 Note: The unused bits (defined as reserved) in I²C registers must be kept to zero.
8.1 I2C Register Map
Register Function and Description
Addr.
(Hex)
Reset Value
(Bin)
Sensitivity/PWM1
00H
0101 0101
SEN_PWM_CH2
SEN_PWM_CH1
Sensitivity/PWM2
01H
0101 0101
SEN_PWM_CH4
SEN_PWM_CH3
Sensitivity/PWM3
02H
0101 0101
SEN_PWM_CH6
SEN_PWM_CH5
Sensitivity/PWM4
03H
0101 0101
-
SEN_PWM_CH7
Sensitivity/PWM5
04H
0101 0101
SEN_PWM_CH9
SEN_PWM_CH8
Sensitivity/PWM6
05H
0101 0101
SEN_PWM_CH11
SEN_PWM_CH10
Sensitivity/PWM7
06H
0101 0101
SEN_PWM_CH13
SEN_PWM_CH12
Sensitivity/PWM8
07H
0101 0101
SEN_PWM_CH15
SEN_PWM_CH14
Sensitivity/PWM9
08H
0101 0101
SEN_PWM_CH17
SEN_PWM_CH16
Sensitivity/PWM10
09H
0101 0101
SEN_PWM_CH19
SEN_PWM_CH18
Name
Bit7
Bit6
Sensitivity/PWM11
0AH
0000 0101
CTRL1
0BH
0100 1010
VPM
Bit5
Bit4
Bit3
Bit2
SSC
0
Bit1
Bit0
SEN_PWM_CH20
MS
FTC
RTC
CTRL2
0CH
0001 0010
Cal_Ctrl
0DH
1111 1010
BF_UP
S/M_SEL IMP_SEL SRST
BF_DOWN
BS_UP
SLEEP
BS_DOWN
RB SEL
Port CTRL1
0EH
0000 0000
CH4
CH3
CH2
CH1
Port CTRL2
0FH
0000 0000
-
CH7
CH6
CH5
Port CTRL3
10H
0000 0000
CH11
CH10
CH9
CH8
Port CTRL4
11H
0000 0000
CH15
CH14
CH13
CH12
Port CTRL5
12H
0000 0000
CH19
CH18
CH17
CH16
Port CTRL6
13H
0000 0000
Cal_Hold1
14H
0000 0000
CH7
CH6
CH5
CH4
CH3
Cal_Hold2
15H
0000 0000
CH14
CH13
CH12
CH11
CH10
CH9
CH8
-
Cal_Hold3
16H
0000 0000
CH20
CH19
CH18
CH17
CH16
CH15
Err_Percent
17H
0000 1101
CH20
-
CH2
Error Count
CH1
Dummy
Error Percent
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ADSemiconductor®
TS20 (20-CH Auto Sensitivity Calibration Capacitive Touch Sensor)
Register Function and Description
Addr.
(Hex)
Reset Value
(Bin)
Output1
20H
0000 0000
-
CH7
CH6
CH5
Output2
21H
0000 0000
CH15
CH14
CH13
CH12
0000 0000
-
-
CH19
Name
Output3
22H
Ref_wr_H
23H
Bit7
Bit6
Bit5
Bit4
D-Error CH20
Bit3
Bit2
Bit1
Bit0
CH4
CH3
CH2
CH1
CH11
CH10
CH9
CH8
CH18
CH17
CH16
Reference(13 ~ 8)
Ref_wr_L
24H
ref_wr_CH1
25H
0000 0000
CH6
CH5
CH4
Reference(7 ~ 0)
CH3
CH2
CH1
Dummy
-
ref_wr_CH2
26H
0000 0000
CH13
CH12
CH11
CH10
CH9
CH8
-
CH7
ref_wr_CH3
27H
0000 0000
CTRL
CH20
CH19
CH18
CH17
CH16
CH15
CH14
Sensitivity_rd_ctrl
28H
0000 0000
-
Sensitivity_RD
29H
Rd_CH
30H
0000 0000
CH6
CH5
CH4
CH3
Rd_CH
31H
0000 0000
CH13
CH12
CH11
CH10
CH9
CH8
-
CH7
Rd_CH
32H
0000 0000
-
CH20
CH19
CH18
CH17
CH16
CH15
CH14
Sen_H
33H
-
-
Sen_L
34H
Ref_H
35H
Ref_L
36H
Rd_CH
37H
0000 0000
CH6
CH5
CH4
CH3
Dummy
-
Rd_CH
38H
0000 0000
CH13
CH12
CH11
CH10
CH9
CH8
-
CH7
Rd_CH
39H
0000 0000
-
CH20
CH19
CH18
CH17
CH16
CH15
CH14
Read Channel Select
Sensitivity(7 ~ 0)
CH2
CH1
Dummy CTRL
Sense(13 ~8)
Sense(7 ~ 0)
-
-
Reference(13 ~ 8)
Reference(7 ~ 0)
CH2
CH1
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ADSemiconductor®
TS20 (20-CH Auto Sensitivity Calibration Capacitive Touch Sensor)
8.2 Sensitivity Control Register
Sensitivity / PWM x
Address (hex) : 00h ~ 0Ah
Type: R/W
Address
Register Name
00h
01h
02h
03h
04h
05h
06h
07h
08h
09h
0Ah
Channel sensitivity and LED Dimming Control
Bit7
Sensitivity/PWM1
Sensitivity/PWM2
Sensitivity/PWM3
Sensitivity/PWM4
Sensitivity/PWM5
Sensitivity/PWM6
Sensitivity/PWM7
Sensitivity/PWM8
Sensitivity/PWM9
Sensitivity/PWM10
Sensitivity/PWM11
Bit6
Bit5
Bit4
Bit3
SEN_PWM_CH2[3:0]
SEN_PWM_CH4[3:0]
SEN_PWM_CH6[3:0]
SEN_PWM_CH9[3:0]
SEN_PWM_CH11[3:0]
SEN_PWM_CH13[3:0]
SEN_PWM_CH15[3:0]
SEN_PWM_CH17[3:0]
SEN_PWM_CH19[3:0]
-
Bit2
Bit1
Bit0
SEN_PWM_CH1[3:0]
SEN_PWM_CH3[3:0]
SEN_PWM_CH5[3:0]
SEN_PWM_CH7[3:0]
SEN_PWM_CH8[3:0]
SEN_PWM_CH10[3:0]
SEN_PWM_CH12[3:0]
SEN_PWM_CH14[3:0]
SEN_PWM_CH16[3:0]
SEN_PWM_CH18[3:0]
SEN_PWM_CH20[3:0]
Description
The sensitivity of channel is possible to adjust by Sensitivity/PWMx register. The following table
shows detail information of sensitivity.
Bit name
Reset
Function
Sensitivity T (= thickness of PC) of Channels @ Cs = 0pF,
4
Normal Step Sensitivity (SSC bit of CTRL1 Register is ‘1’)
SEN_PWM_CHx[3:0]
0101
Port
Control
bits of
3
Port_CTRLx
are
“00”
“10”
3
4
0000
0001
0010
0011
0100
0101
0110
0111
: approximate sensor
: 6.00 ~ 8.00 T
: 4.50 ~ 6.00 T
: 3.50 ~ 5.00 T
: 3.50 ~ 5.00 T
: 3.00 ~ 4.50 T
: 2.25 ~ 3.50 T
: 1.80 ~ 3.00 T
1000
1001
1010
1011
1100
1101
1110
1111
:
:
:
:
:
:
:
:
1.40
1.20
1.00
1.00
0.75
0.50
0.50
0.25
~
~
~
~
~
~
~
~
2.50
2.25
2.00
1.80
1.50
1.25
1.00
0.75
T
T
T
T
T
T
T
T
Sensitivity T (= thickness of PC) of Channels @Cs = 0pF,
Fine Step Sensitivity (SSC bit of CTRL1 Register is ‘0’)
0000
0001
0010
0011
0100
0101
0110
0111
: approximate sensor
: approximate sensor
: approximate sensor
: 6.00 ~ 8.00 T
: 5.50 ~ 7.00 T
: 5.00 ~ 6.50 T
: 4.50 ~ 6.00 T
: 4.00 ~ 5.50 T
1000
1001
1010
1011
1100
1101
1110
1111
:
:
:
:
:
:
:
:
4.00
3.50
3.00
2.75
2.50
2.25
2.00
1.80
~
~
~
~
~
~
~
~
5.00
5.00
4.50
4.00
3.75
3.50
3.25
3.00
T
T
T
T
T
T
T
T
LED dimming controllable up to 16 steps.
0000 : The minimum luminance(Almost Off)
1111 : The maximum luminance
Refer to chapter 8.6 Port Control Register
Refer to chapter 8.3 General Control Register 1
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ADSemiconductor®
TS20 (20-CH Auto Sensitivity Calibration Capacitive Touch Sensor)
8.3 General Control Register 1
CTRL1
General Control Register1
Address (hex): 0Bh
Type: R/W
Bit7
Bit6
0
Bit5
SSC
MS
Bit4
Bit3
FTC[1:0]
Bit2
Bit1
Bit0
RTC[2:0]
Description
The calibration speed just after power on reset is very high during the time which is defined by
FTC[1:0] to have a good adoption against unstable external environment.
Bit name
Reset
Function
RTC[2:0]
010
FTC[1:0]
01
MS
0
SSC
1
Response Time Control
Response period = RTC[2:0] + 2
First Touch Control
00 : 2.5 sec
01 : 5 sec
10 : 10 sec
11 : 20 sec
Operation Mode Selection
0 : auto alternate (fast/slow) mode
1 : fast mode
Sensitivity Step Control
0 : Fine steps
1 : Normal steps
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ADSemiconductor®
TS20 (20-CH Auto Sensitivity Calibration Capacitive Touch Sensor)
8.4 General Control Register2
CTRL2
General Control Register 2
Address (hex): 0Ch
Type: R/W
Bit7
Bit6
VPM
0
Bit5
Bit4
Bit3
Bit2
S/M_SEL
IMP_SEL
SRST
SLEEP
Bit1
Bit0
RB_SEL
Description
2
If SRST bit is set by ‘1’, digital block is reset except analog and I C block.
The SLEEP function allows getting very low current consumption when it is set.
It is possible to reduce the period of sensing burst if VPM bit is set. When user makes CS tact
switch input or LED drive or channel hold, the period of sensing burst is calculated without that
CS channel. And Bit6 must be zero.
Bit name
Reset
Function
5
RB_SEL
10
SLEEP
0
SRST
0
IMP_SEL
1
S/M_SEL
0
VPM
0
Internal System Frequency Speed Control
00,01 : Fast
10 : Normal
11 : Slow
Sleep Mode Enable
0 : Disable Sleep Mode
1 : Enable Sleep Mode
Software Reset
0 : Disable Software Reset
1 : Enable Software Reset
Impedance Select
0 : Low Impedance
1 : High Impedance
Single/Multi Output Mode Select
0 : Multi Mode
1 : Single Mode
5
Variable Period Mode
0 : Disable
1 : Enable
Refer to Chapter 8.6 Port Control Register
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ADSemiconductor®
TS20 (20-CH Auto Sensitivity Calibration Capacitive Touch Sensor)
8.5 Calibration Speed Control Register
Cal_ctrl
Address (hex): 0Dh
Type: R/W
Bit7
Bit6
Calibration Speed Control Register
Bit5
BF_UP
Bit4
BF_DOWN
Bit3
Bit2
BS_UP
Bit1
Bit0
BS_DOWN
Description
The calibration speed might be controlled on each operation mode by Cal_ctrl register.
If BS_DOWN is set “11”, all calibration speed is followed this case(store reference register with
sense count directly) and other register settings are ignored.
Bit name
Reset
Function
BS_DOWN[1:0]
10
BS_UP[1:0]
10
BF_DOWN[1:0]
11
BF_UP[1:0]
11
Calibration speed control lower direction in BS mode
00 : Fastest
01 : Fast
10 : Normal
11 : Store reference register with sense count directly
Calibration speed control upper direction in BS mode
00 : Fastest
01 : Fast
10 : Normal
11 : Slow
Calibration speed control lower direction in BF mode
00 : Fastest
01 : Fast
10 : Normal
11 : Slow
Calibration speed control upper direction in BF mode
00 : Fastest
01 : Fast
10 : Normal
11 : Slow
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ADSemiconductor®
TS20 (20-CH Auto Sensitivity Calibration Capacitive Touch Sensor)
8.6 Ports Control Register
Port_ctrlx
Port Control Register
Address (hex): 0Eh ~ 13h
Type: R/W
Address Register Name
0Eh
0Fh
10h
11h
12h
13h
Bit7
PORT_CTRL1
PORT_CTRL2
PORT_CTRL3
PORT_CTRL4
PORT_CTRL5
PORT_CTRL6
Bit6
Bit5
CH4
CH11
CH15
CH19
-
Bit4
Bit3
CH3
CH7
CH10
CH14
CH18
-
Bit2
CH2
CH6
CH9
CH13
CH17
-
Bit1
Bit0
CH1
CH5
CH8
CH12
CH16
CH20
Description
CS1 ~ CS20 ports have a specific operation with Port_ctrlx register. The following table shows
the detail information about specific operation.
Channel Hold operation is no working mode in specific channel.
And it is recommended to apply software reset when a port goes from other modes to sense.
Bit name
Reset
Function
CHx
Port Operation
00 : Sense
01 : Channel Hold
10 : LED driver
11 : Tact switch input
00
8.7 Channel Calibration Control Register
Cal_holdx
Dummy, Channel 1 ~ 7 Calibration Enable Register
Address (hex): 14h ~ 16h
Type: R/W
Address Register Name
Bit7
14h
15h
16h
Cal_Hold1
Cal_Hold2
Cal_Hold3
CH7
CH14
Bit6
Bit5
Bit4
Bit3
Bit2
Bit1
Bit0
CH6
CH13
CH5
CH12
CH20
CH4
CH11
CH19
CH3
CH10
CH18
CH2
CH9
CH17
CH1
CH8
CH16
Dummy
CH15
Description
The calibration of each channel is independently available to control. Each channel is working
even if a bit is set.
Bit name
Reset
Function
Dummy, Chx
0
Calibration Enable Control
0 : Enable reference calibration (sensing + calibration)
1 : Disable reference calibration (sensing + No calibration)
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ADSemiconductor®
TS20 (20-CH Auto Sensitivity Calibration Capacitive Touch Sensor)
8.8 Noise Environment Overcome Control Register
Err_CTRL
Error mode entering / escape control
Address (hex): 17h
Type: R/W
Bit7
Bit6
-
Bit5
-
Bit4
-
Bit3
Bit2
Bit1
Err_Count
Bit0
Err_Percent
Description
Err_Percent bits are set by I2C interface. And this bit can control the detective noise level and
count. It is possible to prevent malfunction by rapid changes of environment.
Bit name
Reset
Function
Err_Percent
01
Err_Count
011
Error detective level decision
00 : 0.3%
01 : 0.4%
10 : 0.5%
11 : 0.7%
Error detective count decision
000 ~ 111 : [Err_Count] + 1
8.9 Output Register
Output1x
Channel Output Register
Address (hex): 20h ~ 22h
Type: R
Address Register Name
Bit7
20h
21h
22h
Output1
Output2
Output3
CH15
Bit6
Bit5
Bit4
Bit3
Bit2
Bit1
Bit0
CH7
CH14
CH6
CH13
ND
CH5
CH12
CH20
CH4
CH11
CH19
CH3
CH10
CH18
CH2
CH9
CH17
CH1
CH8
CH16
Description
The each channel output of TS20 is provided with 1 bit. It represents to detect result as below
table.
Bit name
Reset
Function
CHx
0
ND
0
Output of channel x
0: No touch
1: Detected touch
Noise Detect Indication
0: Normal State
1: Noisy State
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ADSemiconductor®
TS20 (20-CH Auto Sensitivity Calibration Capacitive Touch Sensor)
8.10 Write Reference Count Register
Ref_count_H, Ref_count_L
Address (hex) : 23h ~ 24h
Type: R/W
Address Register Name
Bit7
23h
24h
Output1
Output2
Register to write the reference count
Bit6
x
Bit5
x
Bit4
Bit3
Bit2
Bit1
Bit0
Ref_count_H
Ref_count_L
Description
User can write the reference data directly. And this register is the reference data register to
write. If the channel user want to write and CTRL bit is set, reference data is updated with data
user want.
Bit name
Reset
Function
Ref_count_H
Ref_count_L
xx000000
00000000
Reference Count high Byte[13 : 8]
Reference Count low Byte[7 : 0]
ref_wr_chx
Channel Register to write reference count
Address (hex): 25h ~ 27h
Type: R/W
Address Register Name
Bit7
25h
26h
27h
ref_wr_ch1
ref_wr_ch2
ref_wr_ch3
CH6
CH13
CTRL
Bit6
Bit5
Bit4
Bit3
Bit2
Bit1
Bit0
CH5
CH12
CH20
CH4
CH11
CH19
CH3
CH10
CH18
CH2
CH9
CH17
CH1
CH8
CH16
Dummy
CH15
CH7
CH14
Description
The channel register to write the reference data. And the selected channel reference data is
updated at CTRL is to be high.
Bit name
Reset
Function
Dummy, CHx
0
CTRL
0
Channel information
0 : No select
1 : Select.
The Command bit to write reference data
1 : Write the reference data (if CTRL bit is ‘1’, user can
not write the reference data)
0 : wait until next command
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ADSemiconductor®
TS20 (20-CH Auto Sensitivity Calibration Capacitive Touch Sensor)
8.11 Sensitivity Read
sen_rd_channel
Address (hex): 28h
Type: R/W
Bit7
Bit6
-
Channel selection register to read sensitivity
Bit5
-
Bit4
Bit3
Bit2
-
Bit1
Bit0
sen_rd_channel
Description
It is possible to read the sensitivity of specific channel directly by I2C interface. And it is
possible to select channel that user want to read the sensitivity by controlling sen_rd_channel
register. The detail information is in following table.
Bit name
Reset
Function
sen_rd_channel
00000
The setting value of each
00001 : Channel
00010 : Channel
00011 : Channel
00100 : Channel
00101 : Channel
00110 : Channel
00111 : Channel
01000 :
01001 : Channel
01010 : Channel
channels
1
2
3
4
5
6
7
8
9
. . . . .
10100 : Channel 19
10101 : Channel 20
Sensitivity_RD
Address (hex): 29h
Type: R
Bit7
Bit6
The sensitivity data register to read
Bit5
Bit4
Bit3
Bit2
Bit1
Bit0
sen_data
Description
It is possible to read the sensitivity of specific channel directly by I2C interface.
Bit name
Reset
Function
sen_data
00000000
The sensitivity data of selected channel
% = value / 2048
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ADSemiconductor®
TS20 (20-CH Auto Sensitivity Calibration Capacitive Touch Sensor)
9 Recommended TS20 Power Up Sequence (Example)
9.1 Recommended TS20 Power Up Flow Chart
Sensitivity Setting
CH1 ~ CH20
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TS20 (20-CH Auto Sensitivity Calibration Capacitive Touch Sensor)
9.2 Recommended TS20 Power Up Sequence Sample
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TS20 (20-CH Auto Sensitivity Calibration Capacitive Touch Sensor)
10 Recommended Circuit Diagram
10.1 Application Example in clean power environment
TS20 Application Example Circuit (Clean power environment)
The CS patterns also should be routed as short as possible and the width of line might be
about 0.25mm (or narrower line).
The capacitor that is between VDD and GND is an obligation. It should be located as close as
possible from TS20.
The CS pattern routing should be formed by bottom metal (opposite metal of touch PAD).
The empty space of PCB must be filled with GND pattern to strengthen GND pattern and to
prevent external noise from interfere with sensing frequency.
The TS20 is reset when power rise from 0V to proper VDD
The LED_GND and GND should be short in the system and the lines are recommended to be
split from the most low impedance ground point to avoid ground bouncing problems.
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ADSemiconductor®
TS20 (20-CH Auto Sensitivity Calibration Capacitive Touch Sensor)
10.2 Application Example in noisy environment
TS20 Application Example Circuit (Noisy environment)
The VDD periodic voltage ripple over 50mV and the ripple frequency is lower than 10 kHz can
cause wrong sensitivity calibration. To prevent above problem, power (VDD, GND) line of touch
circuit should be separated from other circuit. Especially LED driver power line or digital
switching circuit power line certainly should be treated to be separated from touch circuit.
Thanks to the RS1 ~ RS20, CS1 ~ CS20 and CS20, the noise immunity could be improved.
The LED_GND and GND should be short in the system and the lines are recommended to be
split from the most low impedance ground point to avoid ground bouncing problems.
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ADSemiconductor®
TS20 (20-CH Auto Sensitivity Calibration Capacitive Touch Sensor)
10.3 Example – Power Line Split Strategy PCB Layout
A. Not split power line (Bad power line design)
The noise that is generated by AC load or relay can be loaded at 5V power line.
A big inductance might be appeared in case of the connection line between main board and
display board is too long, moreover the voltage ripple could be generated by LED (LCD)
display driver at VDD (5V).
B. Split power line (One 5V regulator used) – Recommended
C. Split power line (Separated 5V regulator used) – Strongly recommended
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ADSemiconductor®
TS20 (20-CH Auto Sensitivity Calibration Capacitive Touch Sensor)
11 MECHANICAL DRAWING
11.1 Mechanical Drawing of TS20 (28 QFN)
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ADSemiconductor®
TS20 (20-CH Auto Sensitivity Calibration Capacitive Touch Sensor)
DIM
MIN
NOM
MAX
A
A1
A3
b
D
E
e
D2
E2
L
L1
aaa
bbb
ccc
ddd
eee
0.80
0.00
0.85
0.90
0.05
0.203 REF
0.20
0.25
4.00 BSC
4.00 BSC
0.40 BSC
2.40
2.50
2.60
2.40
2.50
2.60
0.35
0.40
0.45
0.00
0.10
0.10
0.10
0.10
0.05
0.08
0.15
NOTES
1.0 DIMENSIONING & TOLERANCEING CONFIRM TO ASME
Y14.5M-1994
2.0 ALL DIMENSIONS ARE IN MILLIMETERS. ANGLES ARE
IN DEGREES.
3.0 DIMESION b APPLIES TO METALLIZED TERMINAL AND
IS MEASURED BETWEEN 0.25mm AND 0.30mm FROM
TERMINAL TIP. DIMENSION L1 REPRESENTS
TERMINAL FULL BACK FROM PACKAGE EDGE UP TO
0.1mm IS ACCEPTABLE.
4.0 COPLANARITY APPLIES TO THE EXPOSED HEAT SLUG
AS WELL AS THE TERMINAL.
5.0 RADUS ON TERMINAL IS OPTIONAL.
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ADSemiconductor®
TS20 (20-CH Auto Sensitivity Calibration Capacitive Touch Sensor)
11.2 Mechanical Drawing of TS20 (28 TSSOP)
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TS20 (20-CH Auto Sensitivity Calibration Capacitive Touch Sensor)
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ADSemiconductor®
TS20 (20-CH Auto Sensitivity Calibration Capacitive Touch Sensor)
12 MARKING DESCRIPTION
Device Code
: TS20
Channel Number
Touch Switch Group
Weekly Code
: YY WW
Manufacturing Week
Manufacturing Year
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ADSemiconductor®
TS20 (20-CH Auto Sensitivity Calibration Capacitive Touch Sensor)
NOTES:
LIFE SUPPORT POLICY
AD SEMICONDUCTOR’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN
LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE
PRESIDENT AND GENERAL COUNSEL OF AD SEMICONDUCTOR CORPORATION
The ADS logo is a registered trademark of ADSemiconductor
ⓒ 2006 ADSemiconductor – All Rights Reserved
www.adsemicon.com
www.adsemicon.co.kr
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