TS02K 2-Channel Self Calibration Capacitive Touch Sensor SPECIFICATION V1.3 August 2008 ADSemiconductor Confidential ADSemiconductor® TS02K (2-CH Sensitivity Calibration Capacitive Touch Sensor) 1 Specification 1.1 General Feature 2-Channel capacitive touch sensor with self sensitivity calibration Low power consumption Uniformly adjustable sensitivity Sync function for parallel operation 9 steps sensitivity available without external component Open-drain digital output Embedded noise elimination circuit Embedded Internal power reset circuit RoHS compliant 8SOP package 1.2 Application Home appliance Membrane switch replacement Human interface for toys & interactive games Sealed control panels, keypads 1.3 Package (8 SOP) 1.SYNC1 8.OUT1 2.SYNC2 7.OUT2 3.GND 6.VDD 4.CS1 5.CS2 TS02K 8SOP (Drawings not to scale) ADSemiconductor Confidential 1 / 12 ADSemiconductor® TS02K (2-CH Sensitivity Calibration Capacitive Touch Sensor) 2 Pin Description (8 SOP) PIN Number Name 1 SYNC1 2 SYNC2 3 4 5 6 GND CS1 CS2 VDD I/O Digital Input /Output Digital Input /Output Ground Analog Input Analog Input Power 7 OUT2 Digital Output 8 OUT1 Digital Output Description Sensitivity selection input 1 (Note 1) Sync pulse input /output 1 Sensitivity selection input 2 (Note 1) Sync pulse input /output 2 Supply ground Sense channel 1 Sense channel 2 Power (2.5V ~ 5.0V) Ch2 touch detect output Open drain output (Active Low) Ch1 touch detect output Open drain output (Active Low) Protection VDD/GND VDD/GND VDD VDD/GND VDD/GND GND VDD/GND VDD/GND 3 Absolute Maximum Rating Supply voltage 5.5 V Maximum voltage on any pin VDD+0.3 V Maximum current on any PAD 100mA Continuous power Dissipation 800mW Storage Temperature -50 ~ 150℃ Operating Temperature -20 ~ 75℃ Junction Temperature 150℃ Note Unless otherwise noted, all above are operated in normal temperature 4 ESD & Latch-up Characteristics 4.1 4.2 ESD Characteristics Mode Polarity H.B.M Pos / Neg M.M Pos / Neg C.D.M Pos / Neg Max 7000V 7000V 8000V 400V 600V 600V 800V Reference VDD VSS P to P VDD VSS P to P DIRECT Max 100mA -100mA 8.0V Test Step Latch-up Characteristics Mode I Test V supply over 5.0V Polarity Positive Negative Positive 25mA 1.0V ADSemiconductor Confidential 2 / 12 ADSemiconductor® TS02K (2-CH Sensitivity Calibration Capacitive Touch Sensor) 5 Electrical Characteristics ▪ VDD=3.3V, (Unless otherwise noted), TA = 25℃ Characteristics Symbol Operating supply voltage VDD Current consumption IDD Output maximum sink current Sense input capacitance range Note1 Sense input resistance range Minimum detectable capacitance difference Min Typ Max Units 2.5 3.3 5.0 V VDD= 3.3V - 50 75 VDD= 5.0V - 80 120 TA = 25℃ - - 4.0 ㎃ CS1 CS2 - 10 100 ㎊ RS - 200 1000 Ω 0.2 - - ㎊ ΔC > 0.2pF - 12 - ΔC < 0.2pF - 30M - VDD = 3.3V - 100 - VDD = 5.0V - 80 - - 820 1000 IOUT ΔC Output impedance (open drain) Zo Self calibration time after power on TCAL Maximum bias capacitance CB_MAX Expire Time [Note 2] ET Test Condition CS = 10pF ㎂ Ω VDD=3.3V ms pF 38 sec. Note 1: The sensitivity can be increased with lower CS value. The recommended value of CS is 10pF when using 3T PC(Poly Carbonate) cover and 10 ㎜ x 7 ㎜ touch pattern. Note 2: Expire Time is the maximum time of touch duration. ADSemiconductor Confidential 3 / 12 ADSemiconductor® TS02K (2-CH Sensitivity Calibration Capacitive Touch Sensor) 6 Implementation of TS02K 6.1 Typical current consumption TS02K uses internal bias circuit, so internal clock frequency and current consumption is fixed and no external bias circuit is needed. The typical current consumption curve of TS02K is represented in accordance with VDD voltage as below. Typical current consumption curve of TS02K ADSemiconductor Confidential 4 / 12 ADSemiconductor® TS02K (2-CH Sensitivity Calibration Capacitive Touch Sensor) 6.2 CS implementation RS2 CS2 << Touch PAD2 CS2 RS1 CS1 << Touch PAD1 CS1 The parallel capacitor CS2 is added to CS2 and CS1 to CS1 to adjust sensitivity. The sensitivity will be increased when smaller value of CS2 and CS1 are used. (Ref. below Sensitivity Example Figure) It could be useful in case detail sensitivity mediation is required. The TS02N has two independent touch sensor input CS1 and CS2. Internal touch decision processes of CS1 and CS2 are separated from each other. Therefore two channel touch key board can be designed by using only one TS02N. RS1 and RS2 are serial connection resistors to avoid mal-function from external surge and ESD. From 200Ω to 1kΩ is recommended for RS1 and RS2 values. 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 CS1 and CS2 to touch PAD is recommended to be routed as short as possible to prevent from abnormal touch detect caused by connection line. Sensitivity Example Figure ADSemiconductor Confidential 5 / 12 ADSemiconductor® TS02K (2-CH Sensitivity Calibration Capacitive Touch Sensor) 6.3 SYNC implementation The TS02K has two SYNC pins to make it possible to operate with two optional functions such TM as SYNC function, sensitivity selections. No external component is used for above selections. The determination of SYNC pins connection of TS08P is accomplished initial operation periods. Therefore changing connection of SYNC pin after initial operation period cannot affect the optional function selection. SYNCTM function 6.3.1 TM For SYNC function, all SYNC pins (form SYNC1 to SYNC5) have same function. So, at least, TM one of five SYNC pins operates as SYNC function, TS08P can be operated with other TS08P or TSxx series without interfering with each other. Inside of TS08P, there is internal Oscillator for TM SYNC pulse so no external component is used for SYNC function. Simply, it is needed to TM connect SYNC pin to other SYNC pin of TS08P or TSxx series for using SYNC function. For TM proper SYNC function, less five other TS08P or TSxx series can be connected with. SYNC << st 1 TS02K nd 2 SYNC << TS02K or TS** SYNC pulse SYNC << th 5 TS02K or TS** 6.3.2 Sensitivity selections SYNC1 and SYNC2 pin of TS02K can be used as sensitivity selection pin. Both of two SYNC pins have three methods of connection. Open connection (N.C., SYNC connection), connection to GND, and connection to VDD are these methods. As below table, TS02K has 9 step sensitivity selections. When SYNC1 pin or SYNC2 pin has no connection to GND or VDD, that TM SYNC pin may be simultaneously used for SYNC function. Sensitivity level (thickness [mm] of proper poly-carbonate insulator) of each sensitivity selection SYNC2 N.C. Connect to VDD Connect to GND SYNC1 (SYNC connection) Connect to GND 15.0 8.0 6.5 N.C. (SYNC connection) 12.0 10.0 7.5 Connect to VDD 4.5 3.0 6.0 The size of touch PAD is 10 ㎜ｘ 7 ㎜ used. Note 10: Above proper thickness is reliable but it can be changed by insulator material and application. Note 9: ADSemiconductor Confidential 6 / 12 ADSemiconductor® TS02K (2-CH Sensitivity Calibration Capacitive Touch Sensor) 6.4 OUTPUT implementation VDD ROUT2 ROUT1 OUT2 << OUTPUT2 OUT1 << OUTPUT1 The OUT1 and OUT2 have open drain output structure. For this reason, the connection of pullup resistor ROUT is required between OUT1, OUT2 and VDD. The maximum output sink current is 4mA, so over a few kΩ must be used as ROUT1 and Rout2. Normally 10kΩ is used as ROUT1 and Rout2. The reset value of OUT1 and OUT2 is high in normal situation, and the value is low when a touch is detected on CS1 or CS2. 6.5 Internal reset operation The TS02K 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 TS02K power reset, that helps simple circuit design and to realize the low cost application. ADSemiconductor Confidential 7 / 12 ADSemiconductor® TS02K (2-CH Sensitivity Calibration Capacitive Touch Sensor) 7 Recommended Application Two channel touch key board can be designed by using only one TS02K. The TS02K is embedded intelligent internal power reset circuit that makes possible to save circuit cost because of reducing external components for reset. The sensitivity calibration operation can help to prevent abnormal detection caused by external noise, temperature variation, and supply voltage drop. TS02K Application Example Circuit TS02K is reset by internal reset circuit. VDD voltage rising time should be shorter than 100msec for proper operation. 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. The CS patterns also should be routed as short as possible and the width of line might be about 0.25mm. Parallel capacitor of CS pin could be useful in case detail sensitivity mediation is required such as for complementation sensitivity difference between channels. ADSemiconductor Confidential 8 / 12 ADSemiconductor® TS02K (2-CH Sensitivity Calibration Capacitive Touch Sensor) Serial connection resistor of CS pins may be used to avoid mal-function from external surge and ESD. The capacitor that is between VDD and GND is an obligation. It should be located as close as possible from TS02K. 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 sensitivity can be changed by connection of SYNC1 and SYNC2. (See 6.3.2 Sensitivity selections) The OUT1 ~ OUT2 are open drain output ports. At least, one of five SYNC pins has SYNC connection, TS02K can be operated with other TS02K or TSxx series without interfering with each other. (See 6.3.1 SYNC Unused CS pins may be connected to GND for stable operation. TM function) ADSemiconductor Confidential 9 / 12 ADSemiconductor® TS02K (2-CH Sensitivity Calibration Capacitive Touch Sensor) 7.1 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 ADSemiconductor Confidential 10 / 12 ADSemiconductor® TS02K (2-CH Sensitivity Calibration Capacitive Touch Sensor) 8 PACKAGE DESCRIPTION 8.1 Mechanical Drawing 8.2 Marking Description Device Code : TS02K Type of version Channel Number Touch Switch Group Weekly Code : YY ZZ Manufacturing Year Manufacturing Week ADSemiconductor Confidential 11 / 12 ADSemiconductor® TS02K (2-CH 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 ⓒ 2008 ADSemiconductor – All Rights Reserved www.adsemicon.com www.adsemicon.co.kr ADSemiconductor Confidential 12 / 12