ADA04 8-Channel Auto Sensitivity Calibration Capacitive Touch Sensor SPECIFICATION V1.0 December 2006 Chemtronics.,LTD Chemtronics.,LTD ADA04 (8-CH Auto Sensitivity Calibration Capacitive Touch Sensor) 1 Specification 1.1 General Feature 8-Channel capacitive sensor with auto sensitivity calibration Selectable output operation (single or multi output mode) Low current consumption Uniformly adjustable 3 step sensitivity Sync function for parallel operation Adjustable internal frequency with external resister Open-drain digital output Embedded common and normal noise elimination circuit RoHS compliant 32QFN package 1.2 Application Home application Membrane switch replacement Sealed control panels, keypads Door key-lock matrix application Touch screen replacement application 1.3 Package (32QFN) ADA04 32QFN (Drawings not to scale) Chemtronics.,LTD 1 /16 Chemtronics.,LTD ADA04 (8-CH Auto Sensitivity Calibration Capacitive Touch Sensor) 2 Pin Description (32QFN) PIN No. Name I/O Description Protection 1 RBIAS Analog Input Internal bias adjust input VDD/GND 2 3 SRBIAS Digital Output Sleep mode output (Open drain) VDD/GND CS5 Analog Input CH5 capacitive sensor input VDD/GND 4 CS6 Analog Input CH6 capacitive sensor input VDD/GND 5 CS7 Analog Input CH7 capacitive sensor input VDD/GND 6 CS8 Analog Input CH8 capacitive sensor input VDD/GND 7 CDEG Analog Input 3 step sensitivity level selection VDD/GND 8 N.C. - No Connection - 9 N.C. - No Connection - 10 N.C. - No Connection - 11 N.C. - No Connection - 12 N.C. - No Connection - 13 VSS Ground Supply ground VDD 14 N.C. - No Connection - 15 N.C. - No Connection - 16 17 RST OUT1 Digital Input Digital Output System reset (High reset) CH1 output (Open drain) VDD/GND VDD/GND 18 OUT2 Digital Output CH2 output (Open drain) VDD/GND 19 OUT3 Digital Output CH3 output (Open drain) VDD/GND 20 OUT4 Digital Output CH4 output (Open drain) VDD/GND 21 22 N.C. OUT5 Digital Output No Connection CH5 output (Open drain) VDD/GND 23 OUT6 Digital Output CH6 output (Open drain) VDD/GND 24 OUT7 Digital Output CH7 output (Open drain) VDD/GND 25 OUT8 Digital Output CH8 output (Open drain) VDD/GND 26 IMP_OPT Digital Input IMP. Select input VDD/GND Output mode selection (Single Output / Multi Output Sync pulse input /output 27 SYNC/OPT Digital Input/Output 28 VDD Power 29 CS1 Analog Input CH1 capacitive sensor input VDD/GND 30 CS2 Analog Input CH2 capacitive sensor input VDD/GND 31 CS3 Analog Input CH3 capacitive sensor input VDD/GND CS4 Analog Input CH4 capacitive sensor input Note 1 : Refer to 6.4 SYNC/OPT implementation VDD/GND 32 Note 1) VDD/GND Power (2.5V~5.0V) GND Chemtronics.,LTD 2 /16 Chemtronics.,LTD ADA04 (8-CH Auto Sensitivity Calibration Capacitive Touch Sensor) 3 Absolute Maximum Rating Battery 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 Polarity Pos / Neg Pos / Neg Max Reference 2000V VDD 2000V VSS 2000V P to P 200V VDD 200V VSS 200V P to P 500V C.D.M Pos / Neg DIRECT 800V 4.2 Latch-up Characteristics Mode Polarity Max Positive 200mA Negative -200mA Positive 8.0V I Test V supply over 5.0V Test Step 25mA 1.0V Chemtronics.,LTD 3 /16 Chemtronics.,LTD ADA04 (8-CH Auto Sensitivity Calibration Capacitive Touch Sensor) 5 Electrical Characteristics (Preliminary) ▪ VDD=3.3V, Rb=510k, (Unless otherwise noted), TA = 25℃ Characteristics Symbol Operating supply voltage VDD Current consumption IDD Output maximum sink current IOUT Sense input capacitance range Test Condition Min Typ Max Units 2.5 3.3 5.0 V VDD= 3.3V RB=510k - 80 130 VDD= 5.0V RB=510k - 200 315 TA = 25℃ - - 4.0 ㎃ CS - 10 100 ㎊ RS - 200 1000 Ω Cs = 10pF, CDEG = 200pF 0.2 - - Cs = 10pF, CDEG = 470pF 0.4 - - Cs = 10pF, CDEG = 1000pF ㎂ Note1 Sense input resistance range Minimum detective capacitance difference ΔC 0.8 - - ΔC > 0.2pF, Cs = 10pF, CDEG = 200pF - 12 - ΔC < 0.2pF, Cs = 10pF, CDEG = 200pF - 30M - VDD = 3.3V RB = 510k - 100 - VDD = 5.0V RB = 510k - 80 - VDD = 2.5V 100 200 470 VDD = 3.3V 200 330 680 VDD = 5.0V 300 510 1000 CB_MAX - 820 1000 pF RSYNC 1 2 20 MΩ Output impedance (open drain) Zo Self calibration time after system reset TCAL Recommended bias resistance range RB Note2 Maximum bias capacitance Recommended sync resistance range Ω Note 3 CDEG ms kΩ Short to GND High sensitivity Note 4 Sensitivity level selection ㎊ Open Meddle sensitivity Low sensitivity @VDD=3.3V, 5.0V - 430 ㎊ - Low sensitivity @VDD=2.5V 470 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: The lower RB is recommended in noisy condition. Note 3: CDEG should be in ± 5% tolerance. Note 4: The high sensitivity is not recommended in noisy application. Chemtronics.,LTD 4 /16 Chemtronics.,LTD ADA04 (8-CH Auto Sensitivity Calibration Capacitive Touch Sensor) 6 ADA04 Implementation 6.1 RBIAS implementation VDD CB RB RBIAS << The RBIAS is connected to the resistor to decide the oscillator and internal bias current. The sensing frequency, internal clock frequency and current consumption are therefore able to be adjusted with RB. A voltage ripple on RBIAS can make critical internal error, so CB is connected to the VDD (not GND) is recommended. (The typical value of C B is 820pF and the maximum Value is 1nF.) IDD [uA] 450.0 2.5 V 400.0 3.3 V 5.0 V 350.0 300.0 250.0 200.0 150.0 100.0 50.0 0.0 100 200 300 400 500 RB600 [kΩ] 700 800 900 1000 1100 Normal operation current consumption curve The current consumption curve of ADA04R is represented in accordance with RB value as above. The lower RB requires more current consumption but it is recommended in noisy application. For example, refrigerator, air conditioner and so on. Chemtronics.,LTD 5 /16 Chemtronics.,LTD ADA04 (8-CH Auto Sensitivity Calibration Capacitive Touch Sensor) 6.2 CS implementation RS8 CS8 << Touch PAD8 CS8 RS1 CS1 << Touch PAD1 CS1 The parallel capacitor CS1 is added to CS1 and CS8 to CS8 to adjust sensitivity. The sensitivity will be increased when smaller value of CS is used. (Refer to the below Sensitivity Example Figure) It could be useful in case detail sensitivity mediation is required. The ADA04R has three steps sensitivity and it is available to control with CDEG pin. (Refer to 6.3 CDEG implementation chapters) The ADA04 has eight independent touch sensor input from CS1 to CS8. The internal touch decision process of each channel is separated from each other. Therefore eight channel touch key board application can be designed by using only one ADA04 without coupling problem. The RS is serial connection resistor to avoid mal-function from external surge and ESD. (It might be optional.) From 200Ω to 1kΩ is recommended for RS. 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. Chemtronics.,LTD 6 /16 Chemtronics.,LTD ADA04 (8-CH Auto Sensitivity Calibration Capacitive Touch Sensor) Sensitivity example figure at High sensitivity 6.3 CDEG implementation CDEG << CDEG The ADA04R has internally a standard level to detect the capacitance variation for the decision of touching. The one of four step sensitivity is decided by CDEG. The value of CDEG is represented according to the standard variation level as below table. The tolerance of CDEG capacitance should be within ± 5%. The high sensitivity is not recommended in noisy applications. CDEG capacitor value vs. sensitivity Low Sensitivity Level CDEG Capacitor Typical Value High short to GND Meddle open VDD = 2.5V VDD = 3.3V, 5V 470pF 430pF Chemtronics.,LTD 7 /16 Chemtronics.,LTD ADA04 (8-CH Auto Sensitivity Calibration Capacitive Touch Sensor) 6.4 SYNC/OPT implementation 6.4.1 Output Mode Option This pin will be assigned for the output option selection. It will decide that ADA04 is working on single or multi touch detection mode. It should be implemented as below for these. VDD SYNC/OPT << (Single Mode Implementation) SYNC/OPT << (Multi Mode Implementation) 6.4.2 Multi Chip Application Over two ADA04R can work on the one application at the same time thanks to SYNC function with this pin. The SYNC pulse prevents over two sensing signal from interfering with each other. RSYNC is pull-down resistor of SYNC/OPT pin. Too big value of RSYNC makes the SYNC pulse falling delay, and too small value of RSYNC makes rising delay. Typical value of RSYNC is 2MΩ.The Sync pin should be implemented as below. The ADA04 can also be used with the other TSxx series by employing this SYNC function. The ADA04 could only operate on multi output mode in this configuration. SYNC/OPT << 1st RSYNC SYNC(/OPT)<< 2nd ADA04 or TS** Chemtronics.,LTD 8 /16 Chemtronics.,LTD ADA04 (8-CH Auto Sensitivity Calibration Capacitive Touch Sensor) 6.5 RESET implementation ADA04R has internal data latches, so initial state of these latches must be reset by external reset pulse before normal operation starts. The reset pulse can be controlled by host MCU directly or other reset device. If not, the circuit should be composed as below figure. The reset pulse must have high pulse duration about a few msec to cover power VDD rising time. The recommended value of RRST and CRST are 330KΩ and 100nF. VDD CRST RESET << RRST Recommended reset circuits 1 The better performance is warranted with below reset circuit. The Q1 is turned on and makes reset pulse when power is on and VDD is raised to operating voltage. After a few msec (duration time is determined by R7, R8, C5), Q1 is turned off and ADA04 can be operated with normal sensitivity. VDD R7 200K Q1 2N3906 R8 200K RESET C5 220nF R9 470K Recommended reset circuits 2 Chemtronics.,LTD 9 /16 Chemtronics.,LTD ADA04 (8-CH Auto Sensitivity Calibration Capacitive Touch Sensor) 6.6 Output Circuit Implementation VDD ROUT1 OUT1 OUTPUT1 ROUT2 ROUT3 OUTPUT2 OUT2 ROUT4 OUTPUT3 OUT3 ROUT5 OUTPUT4 OUT4 OUTPUT5 OUT5 ROUT6 OUTPUT6 OUT6 ROUT7 OUTPUT7 OUT7 ROUT8 OUTPUT8 OUT8 The OUTPUT pins have an open drain structure. For this reason, the connection of pull-up resistor ROUT is required between OUTPUT and VDD. The maximum output sink current is 4mA, so over a few kΩ must be used as ROUT. Normally 10kΩ is used as ROUT. The OUTPUT is high in normal situation, and the value is low when a touch is detected on the corresponding CS. Chemtronics.,LTD 10 /16 Chemtronics.,LTD T5 Pad T6 Pad T7 Pad T8 Pad Pad Pad Pad Pad 1 1 1 1 RS8 200 RS7 200 RS6 200 RS5 200 0 0 0 0 R3 330K 0 0 CDEG Note 0 0 CS5 CS6 CS7 CS8 10pF 10pF 10pF 10pF 0 N.C. CB 820pF 8 7 6 5 4 3 2 1 N.C. CDEG CS8 CS7 CS6 CS5 SRBIAS RBIAS 9 N.C. 0 VDD RS4 RS3 RS2 RS1 200 200 200 200 32 CS4 N.C. N.C. 10 VDD G E D C 3 . 6 n oo ti t ra et f en Re :m e el t p o m NI CS4 CS3 CS2 CS1 10pF 10pF 10pF 10pF Pad 1 Pad 1 Pad 1 31 CS3 11 N.C. N.C. 30 CS2 0 0 27 Pad 1 N.C. 12 N.C. N.C. 29 CS1 28 VD D VSS 13 SYNC/OPT N.C. 0 R1 2M 14 N.C. 25 OUT8 26 IM P_OPT N.C. 15 RST 16 ADA04R N.C. T4 T3 T2 T1 Pad Pad Pad Pad 0 OUT1 OUT2 OUT3 OUT4 N.C. OUT5 OUT6 OUT7 CVDD 1uF VDD RO4 10k RO3 10k RO2 10k OUT8 OUT8 RO1 10k 17 18 19 20 21 22 0 R4 330K C2 100nF OUT1 OUT1 OUT2 OUT2 OUT3 OUT3 OUT4 OUT4 OUT5 OUT5 OUT6 OUT6 RO5 10k OUT7 OUT7 RO6 10k 23 N.C. RO7 10k 24 VDD RO8 10k VDD Chemtronics.,LTD ADA04 (8-CH Auto Sensitivity Calibration Capacitive Touch Sensor) 7 Recommended Circuit Diagram ADA04 Application Example Circuit 11 /16 Chemtronics.,LTD ADA04 (8-CH Auto Sensitivity Calibration Capacitive Touch Sensor) 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 lower RB is recommended when ADA04 is used in noisy environment. In PCB layout, RB should not be placed on touch pattern. If not, CB has to be connected. The RB pattern should be routed as short as possible. The CS patterns also should be routed as short as possible and the width of line might be about 0.25mm. The capacitor that is between VDD and GND is an obligation. It should be located as close as possible from ADA04. 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 capacitor which is connected with CDEG allows changing the sensitivity. (See 6.3 CDEG implementation chapter) The ADA04 is reset if RST Pin is high. (See 6.5 Reset implementation chapter) The OUT1 ~ OUT8 are open drain output ports. Therefore the pull-up resistor should be needed as above figure. The ADA04 is working with single output mode if SYNC pin is high and it will be in multi output mode when it’s low. The resistor which is connected with GND should be connected with SYNC pin when the application is required over two ADA04 devices. Chemtronics.,LTD 12 /16 Chemtronics.,LTD ADA04 (8-CH Auto 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 Chemtronics.,LTD 13 /16 Chemtronics.,LTD ADA04 (8-CH Auto Sensitivity Calibration Capacitive Touch Sensor) 8 MECHANICAL DRAWING Chemtronics.,LTD 14 /16 Chemtronics.,LTD ADA04 (8-CH Auto Sensitivity Calibration Capacitive Touch Sensor) DIM A A1 A3 b D E D2 E2 e L L1 P aaa ccc MIN 0.80 0.00 0.18 3.20 3.20 0.35 - NOM 0.85 0.203 REF 0.23 5.00 BSC 5.00 BSC 3.30 3.30 0.50 BSC 0.40 45o BSC 0.15 0.10 MAX 0.90 0.05 0.30 3.40 3.40 0.45 0.10 NOTES 1. ALL DIMENSIONS ARE IN MILLIMETERS. ANGLES ARE IN DEGREES. 2. DIMENSION 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. 3. COPLANARITY APPLIES TO THE EXPOSED HEAT SLUG AS WELL AS THE TERMINAL. 4. RADIUS ON TERMINAL IS OPTIONAL. NOTE: Dimensions are in millimeters 9 MARKING DESCRIPTION Device Code : ADA 04 Device Code Customer Code Weekly Code : YY ZZ R Recognition Code Manufacturing Year Manufacturing Week Chemtronics.,LTD 15 /16 Chemtronics.,LTD ADA04 (8-CH Auto Sensitivity Calibration Capacitive Touch Sensor) NOTES: ⓒ 2006 Chemtronics.,LTD – All Rights Reserved www.chemtronics.co.kr Chemtronics.,LTD 16 /16