SX8652ICSTRT

SX8652 15kV ESD Low Power 4-Wire / 5-Wire Resistive Touchscreen Controller with SPI Interface ADVANCED COMMUNICATIONS & SENSING DATASHEET -----4 KEY PRODUCT FEATURES GENERAL DESCRIPTION The SX8652 is a very low power, high reliability controller for 4-wire and 5-wire resistive touch screens used in PDAs, portable instruments and point-of-sales terminal applications. It features a wide input supply range from 1.65V to 3.7V and low power modes to preserve current when the screen is unintentionally touched. To compute touch screen X-Y coordinates and touch pressure with precision, a low power 12-bit analog-digital converter is activated with the possibility to enable on-chip data averaging processing algorithms to reduce host activity and suppress system noise. The touch screen controller inputs have been specially designed to provide robust on-chip ESD protection of up to ±15kV in both HBM and Contact Discharge, and eliminates the need for external protection devices. The SX8652 is controlled by a high speed SPI™ serial interface. The SX8652 is available in a 4.0 mm x 3.0 mm 14-DFN package and a 1.5 mm x 2.0 mm wafer level chip scale package (WLCSP) for space conscience applications. APPLICATIONS



DSC, DVR, Cell Phones PDA, Pagers Point-of-Sales Terminals Touch-Screen Monitors ORDERING INFORMATION Part Number Package (Dimension in mm) Marking SX8652ICSTRT1 12 - Ball WLCSP (1.5x2.0) FG97 SX8652IWLTRT1 14 - Lead DFN (4.0x 3.0) FG97





Extremely Low Power Consumption: 23uA@1.8V 8kSPS Superior On-chip ESD Protection
±15kV HBM (X+,X-,Y+,Y-)
±2kV CDM
±25kV Air Gap Discharge
±15kV Contact Discharge
±300V MM Single 1.65V to 3.7V Supply/Reference 4-Wire or 5-Wire Resistive Touch Screen Interface Integrated Preprocessing Block to Reduce Host Loading and Bus Activity Four User Programmable Operation Modes provides Flexibility to address Different Application Needs
Manual, Automatic, Pen Detect, Pen Trigger

Low Noise Ratiometric Conversion
Throughput: 5000 (X-Y) coordinates/second (c/s) with 7Sample Averaging



Low Power Shut-Down Mode < 1uA




Hardware & Software reset Precision, High Speed 12-bit SAR ADC Operating At 74k SPS SPI™ Serial Interface Touch Pressure Measurement (4-Wire) Auxiliary Input (4-Wire) For Alternate ADC Input or Start of Conversion Trigger -40°C to +85°C operation Pb-Free, Halogen Free, RoHS/WEEE compliant product Windows CE 6.0, Linux Driver Support Available Packages: 14-LD (4.0 mm x 3.0 mm) DFN 12-Ball (1.5 mm x 2.0 mm) WLCSP 1. 3000 Units / reel VDD S X 865 2 VDD C o ntrol N IR Q A U X /W IP E R N R S T (D FN only) POR T o the touch screen SPI X + /B R Y + /TR Touch S creen Interface S C LK ref+ X -/TL Y -/B L V ref NCS OSC in A D C out ref- D igital Filter T o the H o st DOUT D IN GND Revision V1.7/October 2010 ©2010 Semtech Corp. Page 1 www.semtech.com SX8652 ADVANCED COMMUNICATIONS & SENSING DATASHEET Table of contents Section 1. 2. 3. 4. 5. Page General Description ................................................................................................................................................. 4 1.1. DFN Pinout Diagram and Marking Information (Top View).............................................................................. 4 1.2. WLCSP Pinout Diagram and Marking Information (Top View) ........................................................................ 4 1.3. Pin Description................................................................................................................................................. 5 1.4. Simplified Block Diagram ................................................................................................................................. 5 Electrical Characteristics ......................................................................................................................................... 6 2.1. Absolute Maximum Ratings ............................................................................................................................. 6 2.2. Recommended Operating Conditions.............................................................................................................. 6 2.3. Thermal Characteristics ................................................................................................................................... 6 2.4. Electrical Specifications ................................................................................................................................... 7 2.5. Host Interface Specifications ........................................................................................................................... 9 2.6. Host Interface Timing Waveforms.................................................................................................................... 9 Functional Description ........................................................................................................................................... 10 3.1. General Introduction ..................................................................................................................................... 10 3.2. Device Interface and ESD protection............................................................................................................. 11 3.2.1. Touchscreen interface............................................................................................................................. 11 3.2.2. Host Interface and Control Pins .............................................................................................................. 11 4-wire Touch Screen Detailed Description ............................................................................................................ 12 4.1. Touch Screen Operation................................................................................................................................ 12 4.2. Coordinates Measurement............................................................................................................................. 12 4.3. Pressure Measurement.................................................................................................................................. 13 4.4. Pen Detection ................................................................................................................................................ 13 5-wire Touch Screen Detailed Description ............................................................................................................ 14 5.1. Touch Screen Operation................................................................................................................................ 14 5.2. Coordinates Measurement............................................................................................................................. 14 5.3. Pen Detection ................................................................................................................................................ 14 6. Data Processing .................................................................................................................................................... 15 7. Power-Up, Reset ................................................................................................................................................... 15 8. Modes of Operation ............................................................................................................................................... 15 9. 8.1. MANual Mode ................................................................................................................................................ 16 8.2. AUTOmatic mode .......................................................................................................................................... 16 8.3. PENDET Mode .............................................................................................................................................. 17 8.4. PENTRIG Mode ............................................................................................................................................. 17 Host Interface ........................................................................................................................................................ 19 9.1. SPI Read/Write Registers .............................................................................................................................. 19 9.2. SPI Reading Channel Data............................................................................................................................ 19 9.3. SPI Host Commands ..................................................................................................................................... 20 9.4. SPI implementation and multiple Read/Write ................................................................................................ 20 9.5. Invalid Qualified Data..................................................................................................................................... 21 Revision V1.7/October 2010 ©2010 Semtech Corp. Page 2 www.semtech.com SX8652 ADVANCED COMMUNICATIONS & SENSING DATASHEET Table of contents Section 10. Page 9.6. Register Map................................................................................................................................................. 22 9.7. SX8652 register ............................................................................................................................................ 23 Application Information ......................................................................................................................................... 24 10.1. Acquisition Setup ........................................................................................................................................... 24 10.2. Channel Selection.......................................................................................................................................... 24 10.3. Noise Reduction............................................................................................................................................. 24 10.3.1. POWDLY................................................................................................................................................. 24 10.3.2. SETDLY .................................................................................................................................................. 25 10.4. AUX Input - 4-wire touchscreen only ............................................................................................................. 25 10.5. Interrupt Generation....................................................................................................................................... 25 10.6. Coordinate Throughput Rate ......................................................................................................................... 25 10.6.1. SPI Communication Time ....................................................................................................................... 25 10.6.2. Conversion Time ..................................................................................................................................... 26 10.7. ESD event...................................................................................................................................................... 26 11. Packaging Information ........................................................................................................................................... 27 11.1. DFN Package................................................................................................................................................. 27 11.2. WLCSP Package ........................................................................................................................................... 28 Revision V1.7/October 2010 ©2010 Semtech Corp. Page 3 www.semtech.com SX8652 15kV ESD Low Power 4-Wire / 5-Wire Resistive Touchscreen Controller with SPI Interface ADVANCED COMMUNICATIONS & SENSING DATASHEET 1. General Description 1.1. DFN Pinout Diagram and Marking Information (Top View) 1 14 (NC) VDD 2 13 NRST X+/BR 3 12 NCS Y+/TR 4 11 NIRQ X-/TL 5 10 DOUT Y-/BL 6 9 DIN GND 7 8 SCLK 15 PIN 1 IDENTIFIER FG97 YYWW XXXXX AUX/ WIPER Figure 1. SX8652 DFN Top View, Pad on Bottom Side YYWW: date code XXXXX: Lot Number 1.2. WLCSP Pinout Diagram and Marking Information (Top View) X+/BR Y+/TR X-/TL Y-/BL FG97 YYWW XXXXXX 3 VDD NCS DIN GND AUX/WIPER # NIRQ DOUT SCLK A B C D 2 1 BALL A1 IDENTIFIER Figure 2. SX8652 WLCSP Top View, Solder Bumps on Bottom Side YYWW: date code XXXXX: Lot Number Revision V1.7/October 2010 ©2010 Semtech Corp. Page 4 www.semtech.com SX8652 15kV ESD Low Power 4-Wire / 5-Wire Resistive Touchscreen Controller with SPI Interface ADVANCED COMMUNICATIONS & SENSING DATASHEET 1.3. Pin Description Pin Number # Name Type Description DFN WLCSP 1 A1 AUX/WIPER Digital Input / Analog Input Conversion Synchronization (4-wire) or Analog Auxiliary Input (4-wire) / Wiper Input (5-wire) 2 A2 VDD Power Input Input power supply, connect to a 0.1uF capacitor to GND 3 A3 X+/BR Analog IO X+ Right electrode (4-wire) / Bottom Right (5-wire) channel 4 B3 Y+/TR Analog IO Y+ Top electrode (4-wire) /Top Right (5-wire) channel 5 C3 X-/TL Analog IO X- Left electrode (4-wire) /Top Left (5-wire) channel 6 D3 Y-/BL Analog IO Y- Bottom electrode (4-wire) /Bottom Left (5-wire) channel 7 D2 GND Ground Ground 8 D1 SCLK Digital Input SPI Serial Clock Input 9 C2 DIN Digital Output SPI Serial Data Input 10 C1 DOUT Digital Output SPI Serial Data Output 11 B1 NIRQ Digital Output, open drain Interrupt Request Output, Active low, Need external pull-up 12 B2 NCS Digital Input SPI Chip Select Input, Active low 13 - NRST Digital Input DFN package only, Reset Input, Active low, Internal pull-up resistor 14 - (NC) 15 - GND Not Connected Power input Backside Ground Table 1. Pin description 1.4. Simplified Block Diagram The SX8652 simplified block diagram is shown in Figure 3. VDD SX8652 VDD Control NIRQ AUX/WIPER NRST (DFN only) POR To the touch screen SPI X+/BR Y+/TR Touch Screen Interface X-/TL Y-/BL Vref NCS OSC SCLK ref+ in ADC out ref- Digital Filter To the Host DOUT DIN GND Figure 3. Simplified block diagram of the SX8652 Revision V1.7/October 2010 ©2010 Semtech Corp. Page 5 www.semtech.com SX8652 15kV ESD Low Power 4-Wire / 5-Wire Resistive Touchscreen Controller with SPI Interface ADVANCED COMMUNICATIONS & SENSING DATASHEET 2. Electrical Characteristics 2.1. Absolute Maximum Ratings Stresses above the values listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these, or any other conditions beyond the “Recommended Operating Conditions”, is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Parameter Symbol Min. Max. Unit Supply Voltage VDDABS -0.5 3.9 V Input voltage (non-supply pins) VIN -0.5 3.9 V Input current (non-supply pins) IIN 10 mA Operating Junction Temperature TJCT 125 °C Reflow temperature TRE 260 °C Storage temperature TSTOR 150 °C ESD HBM (Human Body Model) ESD (Contact Discharge) ± 15(i) kV ± 8(ii) kV ESDHBM2 ±2 kV ESDCD ± 15 kV ILU ± 100 mA High ESD pins: X+/BR, X-/TL, Y+/TR, Y-/BL, Aux/Wiper ESDHBM1 All pins except high ESD pins High ESD pins: X+/BR, X-/TL, Y+/TR, Y-/BL, Aux/Wiper Latchup(iii) -50 Table 2. Absolute Maximum Ratings (i) Tested to TLP (10A) (ii) Tested to JEDEC standard JESD22-A114 (iii) Tested to JEDEC standard JESD78 2.2. Recommended Operating Conditions Parameter Supply Voltage Ambient Temperature Range Symbol Min. Max Unit VDD 1.65V 3.7 V TA -40 85 °C Min. Max Unit Table 3. Recommended Operating Conditions 2.3. Thermal Characteristics Symbol Parameter Thermal Resistance with DFN package - Junction to Ambient (iii) θJA 39 °C/W Thermal Resistance with WLCSP package - Junction to Ambient (iii) θJA 65 °C/W Table 4. Thermal Characteristics (iii) θJA is calculated from a package in still air, mounted to 3" x 4.5", 4 layer FR4 PCB with thermal vias under exposed pad (if applicable) per JESD51 standards. Revision V1.7/October 2010 ©2010 Semtech Corp. Page 6 www.semtech.com SX8652 15kV ESD Low Power 4-Wire / 5-Wire Resistive Touchscreen Controller with SPI Interface ADVANCED COMMUNICATIONS & SENSING DATASHEET 2.4. Electrical Specifications All values are valid within the recommended operating conditions unless otherwise specified. Symbol Parameter Conditions Min. Typ Max Unit Current consumption Mode = MANUAL Ipwd Converter stopped, pen detection off, SPI listening, OSC stopped 0.4 1 uA Mode = PENDET Ipndt Converter stopped, pen detection activated, device generates interrupt upon detection, SPI listening, OSC stopped 0.4 1 uA Mode =PENTRIG Ipntr Converter stopped, pen detection activated, device starts conversion upon pen detection. SPI listening, OSC stopped 0.4 1 uA Mode=AUTO Iauto Converter stopped, pen detection off, SPI listening, OSC on, timer on 1.5 Operation @8kSPS, VDD=1.8V Iopl 23 50 uA Operation @42kSPS, VDD=3.3V Ioph 105 140 uA uA Digital I/O High-level input voltage VIH 0.8VDD VDD+0.2 V Low-level input voltage VIL VSS-0.3 0.2VDD V VHysLow VDD > 2V 0.05 VDD V VHysHigh VDD < 2V 0.1 VDD V Output Logic High VOH IOH>-2mA 0.8VDD Output Logic Low VOL IOL0), pen detect (command ‘PENDET’), pen trigger mode (command ‘PENTRG’). Revision V1.7/October 2010 ©2010 Semtech Corp. Page 15 www.semtech.com SX8652 15kV ESD Low Power 4-Wire / 5-Wire Resistive Touchscreen Controller with SPI Interface ADVANCED COMMUNICATIONS & SENSING DATASHEET In the PENDET mode the pen detection is activated. The SX8652 will generate an interrupt (NIRQ) upon pen detection and set the PENIRQ bit in the SPI status register. To quit the PENDET mode the host needs to configure the manual mode. In the PENTRG mode the pen detection is activated and a channel conversion will start after the detection of a pen. The SX8652 will generate an interrupt (NIRQ) upon pen detection and set the CONVIRQ bit in the SPI status register. To quit the PENTRIG mode the host needs to configure the manual mode. The PENTRG mode offers the best compromise between power consumption and coordinate throughput. 8.1. MANual Mode In manual mode (RATE=0), the host sequences all the actions by the SPI commands described in Table 9. When a command is received, the SX8652 executes the associated task and waits for the next command. Command Action Select and bias a channel Wait for the programmed settling time (POWDLY) CONVERT(CHAN) Start conversion Select and bias a channel SELECT(CHAN) Table 9. CONVERT and SELECT command The channel can be biased for an arbitrary amount of time by first sending a SELECT command and then a CONVERT command once the settling time requirement is met. The SELECT command can be omitted if the large range of POWDLY settings cover the requirements. In the latter case, the CONVERT command alone is enough to perform an acquisition. With CHAN=SEQ, multiple channels are sampled. This requires programming the POWDLY field in register RegCTRL0. The selected channel will be powered during POWDLY before a conversion is started. The channel bias is automatically removed after the conversion has completed. 8.2. AUTOmatic mode In automatic mode (RATE > 0), SX8652 start the acquisition when a touch is detected. It converts all the channels selected with RegChnMsk and set NIRQ low when it is finished. After the host has read the channels, if CONDIRQ=1 and the touch is detected again, the SX8652 starts a new conversion cycle. To not loose data, the SX8652 does not begin conversion before the host read all the channels. We can define the time ts between the start of the conversion and the end of the channels reading by the host. The rate programmed is achieved if ts0: Automatic mode 7:4 0000 RATE RegCtrl0 0000: Timer disabled -Manual mode 0001: 10 cps 0010: 20 cps 0011: 40 cps 0100: 60 cps 0101: 80 cps 0110: 100 cps 0111: 200 cps 1000: 300 cps 1001: 400 cps 1010: 500 cps 1011: 1k cps 1100: 2k cps 1101: 3k cps 1110: 4k cps 1111: 5k cps Conversion (or first conversion when filtering is enabled) settling time (± 10%) 3:0 7:6 0000 00 POWDLY AUXAQC 0000: Immediate (0.5 us) 0001: 1.1 us 0010: 2.2 us 0011: 4.4 us 0100: 8.9 us 0101: 17.8 us 0110: 35.5 us 0111: 71.0 us 1000: 0.14 ms 1001: 0.28 ms 1010: 0.57 ms 1011: 1.14 ms 1100: 2.27 ms 1101: 4.55 ms 1110: 9.09 ms 1111: 18.19 ms 00: AUX is used as an analog input (4wire only) 01: On rising AUX edge, wait POWDLY and start acquisition 10: On falling AUX edge, wait POWDLY and start acquisition 11: On rising and falling AUX edges, wait POWDLY and start acquisition The AUX trigger works only in manual mode with 4-wire touchscreen 5 1 CONDIRQ Enable conditional interrupts 0: interrupt always generated at end of conversion cycle. If no pen is detected the data is set to ‘invalid qualified’. 4 0 SCREEN Select the type of screen: 0: 4-wire 1: 5 -wire 10: 50 kOhm 11: 25 kOhm RegCtrl1 RegCtrl2 1: interrupt generated when pen detect is successful 3:2 00 RPDNT Select the Pen Detect Resistor 00: 100 kOhm 01: 200 kOhm 1:0 00 FILT Digital filter control 00: Disable 01: 3 sample averaging 10: 5 sample averaging 11: 7 sample acquisition, sort, average 3 middle samples 7:4 0 reserved Settling time while filtering (± 10%) 0000: Immediate (0.5 us) 0001: 1.1 us 0010: 2.2 us 0011: 4.4 us 0100: 8.9 us 0101: 17.8 us 0110: 35.5 us 0111: 71.0 us 1000: 0.14 ms 1001: 0.28 ms 1010: 0.57 ms 1011: 1.14 ms 1100: 2.27 ms 1101: 4.55 ms 1110: 9.09 ms 1111: 18.19 ms 3:0 0000 SETDLY Table 15. SX8652 Register Revision V1.7/October 2010 ©2010 Semtech Corp. Page 23 www.semtech.com SX8652 15kV ESD Low Power 4-Wire / 5-Wire Resistive Touchscreen Controller with SPI Interface ADVANCED COMMUNICATIONS & SENSING DATASHEET Register Bit Default RegChanMsk Description 7 1 XCONV 0: no sample 1: Sample X channel 6 1 YCONV 0: no sample 1: Sample Y channel 5 0 Z1CONV 0: no sample 1: Sample Z1 channel 4 0 Z2CONV 0: no sample 1: Sample Z2 channel 3 0 AUXCONV 0: no sample 1: Sample AUX channel 0 0 reserved 0 0 reserved 0 0 reserved Host writing to this register is ignored. RegStat RegSoftReset 7 0 CONVIRQ 0: no IRQ pending 1: Conversion sequence finished IRQ is cleared by the channel data read command 6 0 PENIRQ Operational in pen detect mode 0: no IRQ pending 1: Pen detected IRQ pending IRQ is cleared by the RegStat reading 5 1 RSTEVENT A reset event has occurred 4:0 00000 7:0 0x00 reserved Writing 0xDE to this register reset the SX8652 Any other data will not affect the SX8652 Table 15. SX8652 Register 10. Application Information This section describes in more detail application oriented data. 10.1. Acquisition Setup Prior to an acquisition, the SX8652 can be setup by writing the control registers. Registers are written by issuing the register write command. They can be read by issuing the read command. Please refer to the section [9.7]. 10.2. Channel Selection The SX8652 can be setup to start a single channel conversion or to convert several channels in sequence. For a single conversion, the channel to be converted is determined from the CHAN(2:0) field in the command word (defined in Table 12). Several channels defined in RegChanMsk can be acquired sequentially by setting the CHAN(2:0) field to SEQ. The channels will be sampled in the order X, Y, Z1, Z2, AUX. 10.3. Noise Reduction A noisy environment can decrease the performance of the controller. For example, an LCD display located just under the touch screen can adds a lot of noise on the high impedance A/D converter inputs. 10.3.1. POWDLY In order to perform correct coordinates acquisition properly, some time must be given for the touch screen to reach a proper level. It is a function of the PCB trace resistance connecting the SX8652 to the touchscreen and also the Revision V1.7/October 2010 ©2010 Semtech Corp. Page 24 www.semtech.com SX8652 15kV ESD Low Power 4-Wire / 5-Wire Resistive Touchscreen Controller with SPI Interface ADVANCED COMMUNICATIONS & SENSING DATASHEET capacitance of the touchscreen. We can define tau as the RC time constant. POWDLY duration should be programmed to 10 tau to reach 12 bit accuracy. Adding a capacitor from the touch screen drivers to ground is a solution to minimize external noise but it increases settling time and consequently the power consumption. 10.3.2. SETDLY A best method to filter noise is described in section [6] (Data processing). When filtering is enabled, the channel will be biased initially during a time of POWDLY for the first conversion. The parameter SETDLY sets the settling time between the subsequent conversions in a filter set. In most applications, SETDLY can be set to 0. In applications with a high tau and where accuracy of 1LSB is required SETDLY should be increased. 10.4. AUX Input - 4-wire touchscreen only The AUX input can be used to sample an analog signal in the range 0-VDD. For system supply by battery, the battery voltage can be monitored for example. The conversion is done in sequence with the touchscreen acquisition therefore the sample rate is defined with RegCtrl0 in AUTO mode. The AUX pin can also triggered conversions. A rising edge, a falling edge or both applied on the AUX pin can trigger the conversion. This is defined by AUXACQ in RegCtrl1. This method can be used to sample touchscreen when there is noise-free periods. 10.5. Interrupt Generation An interrupt (NIRQ=0) will be generated:

During the power-up phase or after a reset
After a touch on the panel being detected in PENDET mode. PENIRQ (bit [6] of RegStat) will be set at the same time. After completion of a conversion in MANUAL, PENTRIG or AUTO mode. CONVIRQ (bit [7] of RegStat) will be set at the same time. The NIRQ will be released and pulled high(NIRQ=1) by the external pull-up resistor:

When the power-up phase is finished When the host read all channels data that were previously converted by the SX8652 in MANUAL, PENTRIG or AUTO mode. CONVIRQ will be cleared at the same time.
When the host read the status register in PENDET mode. PENIRQ, will be cleared at the same time. An active NIRQ (low) needs to be cleared before any new conversions will occur. 10.6. Coordinate Throughput Rate The coordinate throughput rate depends on the following factors:

The SPI communication time: Tcom The conversion time: Tconv 1 The coordinate rate is the frequency to get the X, Y, Z1 and Z2 coordinate: CoordRate = ------------------------------T com + T conv 10.6.1. SPI Communication Time The minimum time to read the channel data in PENTRIG mode is: T com = ( 8 + 16 × N chan ) × T SPI The highest throughput will be obtained with a SPI frequency of 5MHz when the host read the channel data as quickly as possible after the NIRQ falling edge. Revision V1.7/October 2010 ©2010 Semtech Corp. Page 25 www.semtech.com SX8652 15kV ESD Low Power 4-Wire / 5-Wire Resistive Touchscreen Controller with SPI Interface ADVANCED COMMUNICATIONS & SENSING DATASHEET 10.6.2. Conversion Time The maximum possible throughput can be estimated with the following equation T conv = 47 ⋅ T osc + N chan [ POWDLY + SETDLY ( N filt – 1 ) + T osc ( 21N filt + 1 ) ] with:




Nfilt = {1,3,5,7} based on the order defined for the filter FILT (see Figure 8). Nchan = {1,2,3,4,5} based on the number of channels defined in RegChanMsk POWDLY = 0.5us to 18.19ms, settling time as defined in RegCtrl0 SETDLY = 0.5us to 18.19ms, settling time when filtering as defined in RegCtrl2 Tosc is the oscillator period (555ns +/- 15%) Table 16 gives some examples of Coordinate Rate and Sample Rate for various setting in PENTRIG mode. Nch [1..5 ] Nfilt [1 3 5 7] PowDly [uS] SetDly [uS] 2 1 0.5 - 2 3 71 4 3 140 Tconv [uS] Tcomm [uS] CoordRate [kSPS] 51 8 16.7 0.5 190 8 5.0 0.5 740 14 1.3 Table 16. Coordinate throughput examples 10.7. ESD event In case of ESD event, the chip may reset to protect its internal circuitry. The bit RSTEVENT indicates that a reset event has occurs. ESD event may trig the pen detection circuitry. In this case wrong data will be send to the host. To detect this false coordinates on 4-wire touchscreen, Z1 and Z2 can be read. The conditions Z1HighThreshold indicate an ESD event. The values LowThreshold and HighThreshold are given for indication only on the table below and should be fine tune according to the system. LowThreshold HighThreshold 10 4070 Table 17. Threshold to detect false coordinates Revision V1.7/October 2010 ©2010 Semtech Corp. Page 26 www.semtech.com SX8652 15kV ESD Low Power 4-Wire / 5-Wire Resistive Touchscreen Controller with SPI Interface ADVANCED COMMUNICATIONS & SENSING DATASHEET 11. Packaging Information 11.1. DFN Package A B D DIMENSIONS MILLIMETERS MIN NOM MAX DIM PIN1 INDICATOR (LASER MARK) A A1 A2 b D D1 E E1 e L N aaa bbb E A SEATING PLANE aaa C A1 A2 0.80 0.70 0.00 0.02 0.05 - (0.20) 0.18 0.25 0.30 3.90 4.00 4.10 3.05 3.20 3.30 2.90 3.00 3.10 1.55 1.70 1.80 0.50 BSC 0.30 0.40 0.50 14 0.08 0.10 C LxN D1 1 2 E/2 E1 N bxN e bbb C A B D/2 NOTES: 1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES). 2. COPLANARITY APPLIES TO THE EXPOSED PAD AS WELL AS THE TERMINALS. Figure 18. DFN Package Outline Drawing DIMENSIONS DIM C G H K P X Y Z MILLIMETERS (2.90) 2.20 1.70 3.30 0.50 0.30 0.70 3.60 NOTES: 1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES). 2. THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY. CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR COMPANY'S MANUFACTURING GUIDELINES ARE MET. 3. THERMAL VIAS IN THE LAND PATTERN OF THE EXPOSED PAD SHALL BE CONNECTED TO A SYSTEM GROUND PLANE. FAILURE TO DO SO MAY COMPROMISE THE THERMAL AND/OR FUNCTIONAL PERFORMANCE OF THE DEVICE. Figure 19. DFN Package Land Pattern Revision V1.7/October 2010 ©2010 Semtech Corp. Page 27 www.semtech.com SX8652 15kV ESD Low Power 4-Wire / 5-Wire Resistive Touchscreen Controller with SPI Interface ADVANCED COMMUNICATIONS & SENSING DATASHEET 11.2. WLCSP Package B 1.5±0.10 A INDEX AREA A1 CORNER 2.0±0.10 0.10 C 0.625 Max. 0.25±0.02 SEATING PLANE C 1.00 0.08 C 0.50 D 0.50 C 1.50 B 0.25 A 1 2 3 12X Ø0.315±0.03 0.05 C A B NOTES: 1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS Figure 20. WLCSP Package Outline Drawing 1.00 0.50 0.50 0.25 1.50 12X Ø0.25 NOTES: 1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS 2. THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY. CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR COMPANY'S MANUFACTURING GUIDELINES ARE MET. Figure 21. WLCSP Land Pattern of WLCSP Revision V1.7/October 2010 ©2010 Semtech Corp. Page 28 www.semtech.com SX8652 DATASHEET ADVANCED COMMUNICATIONS & SENSING © S e m te c h 2 0 1 0 A ll rig h ts re s e rv e d . R e p ro d u c tio n in w h o le o r in p a rt is p ro h ib ite d w ith o u t th e p rio r w ritte n c o n s e n t o f th e c o p y rig h t o w n e r. T h e in fo rm a tio n p re s e n te d in th is d o c u m e n t d o e s n o t fo rm p a rt o f a n y q u o ta tio n o r c o n tra c t, is b e lie v e d to b e a c c u ra te a n d re lia b le a n d m a y b e c h a n g e d w ith o u t n o tic e . N o lia b ility w ill b e a c c e p te d b y th e p u b lis h e r fo r a n y c o n s e q u e n c e o f its u s e . P u b lic a tio n th e re o f d o e s n o t c o n v e y n o r im p ly a n y lic e n s e u n d e r p a te n t o r o th e r in d u s tria l o r in te lle c tu a l p ro p e rty rig h ts . S e m te c h a s s u m e s n o re s p o n s ib ility o r lia b ility w h a ts o e v e r fo r a n y fa ilu re o r u n e x p e c te d o p e ra tio n re s u ltin g fro m m is u s e , n e g le c t im p ro p e r in s ta lla tio n , re p a ir o r im p ro p e r h a n d lin g o r u n u s u a l p h y s ic a l o r e le c tric a l s tre s s in c lu d in g , b u t n o t lim ite d to , e x p o s u re to p a ra m e te rs b e y o n d th e s p e c ifie d m a x im u m ra tin g s o r o p e ra tio n o u ts id e th e s p e c ifie d ra n g e . S E M T E C H P R O D U C T S A R E N O T D E S IG N E D , IN T E N D E D , A U T H O R IZ E D O R W A R R A N T E D T O B E S U IT A B L E F O R U S E IN L IF E -S U P P O R T A P P L IC A T IO N S , D E V IC E S O R S Y S T E M S O R O T H E R C R IT IC A L A P P L IC A T IO N S . IN C L U S IO N O F S E M T E C H P R O D U C T S IN S U C H A P P L IC A T IO N S IS U N D E R S T O O D T O B E U N D E R T A K E N S O L E L Y A T T H E C U S T O M E R ’S O W N R IS K . S h o u ld a c u s to m e r p u rc h a s e o r u s e S e m te c h p ro d u c ts fo r a n y s u c h u n a u th o riz e d a p p lic a tio n , th e c u s to m e r s h a ll in d e m n ify a n d h o ld S e m te c h a n d its o ffic e rs , e m p lo y e e s , s u b s id ia rie s , a ffilia te s , a n d d is trib u to rs h a rm le s s a g a in s t a ll c la im s , c o s ts d a m a g e s a n d a tto rn e y fe e s w h ic h c o u ld a ris e . A ll re fe re n c e d b ra n d s , p ro d u c t n a m e s , s e rv ic e n a m e s a n d tra d e m a rk s a re th e p ro p e rty o f th e ir re s p e c tiv e o w n e rs . Contact information Semtech Corporation Advanced Communications & Sensing Products E-mail: sales@semtech.comacsupport@semtech.comInternet: http://www.semtech.com USA 200 Flynn Road, Camarillo, CA 93012-8790. Tel: +1 805 498 2111 Fax: +1 805 498 3804 FAR EAST 12F, No. 89 Sec. 5, Nanking E. Road, Taipei, 105, TWN, R.O.C. Tel: +886 2 2748 3380 Fax: +886 2 2748 3390 EUROPE Semtech Ltd., Units 2 & 3, Park Court, Premier Way, Abbey Park Industrial Estate, Romsey, Hampshire, SO51 9DN. Tel: +44 (0)1794 527 600 Fax: +44 (0)1794 527 601 ISO9001 CERTIFIED Revision V1.7/October 2010 ©2010 Semtech Corp. Page 29 www.semtech.com