UR7HCTS2-USB Ultimate USB ScreenCoder® 4/5/8-Wire USB Touch Screen Encoder HID & SYSTEM MANAGEMENT PRODUCTS, SCREENCODER® FAMILY DESCRIPTION The UR7HCTS2-USB Ultimate USB ScreenCoder® is the first single IC that seamlessly interfaces ANY 4wire, 5-wire, or 8-wire resistive touch screen to a USB-equipped system. It is also the first touch screen controller IC on the market designed to accommodate a very wide range of size, capacitance and resistance of touch screens, providing a universal performance solution among different OEM products and touch screen vendors. This unique feature of the IC provides OEMs with a wide variety of interchangeable touch screen options. Unlike implementations with separate digitizers, the UR7HCTS2-USB integrates a digitizer with a controller that performs all touch detection, noise filtering, error elimination and provides the host with processed and stable positioning data over USB. Semtech’s unique motion algorithms provide high resistance to RF and other noise sources resulting in precise, jitter-free cursor control. PRELIMINARY FEATURES • Controller & digitizer in a single IC • Interfaces the system via USB • Works with ANY 4-, 5-, or 8-wire resistive touch screen regardless of size, material or vendor • Provides high resolution: 1000 points per axis, enabling IC to make precise drawing and signature captures • Accurate, quick touch response due to Semtech’s advanced sampling technology and algorithms • Highly resistant to RF and other noise • No digitizer or external A/D necessary • Fully compliant with USB HID absolute-mode pointing device specifications • Free driver with calibration applet available for Windows® 98 SE, Windows® Me, Windows® 2000, and Windows® XP • Uses 36-pin SSOP package APPLICATIONS • Handheld PCs (H/PCs) • Notebook PCs • Portable devices • Interactive kiosks • Industrial/custom touch screens PIN ASSIGNMENTS 1 N/C N/C N/C SXL/NW_AD SYT/NE_AD SYB/SW_AD SXR/SE_AD SENSE_DRV SENSE_AD N/C N/C VREF _RESET VSS2 VDD OSCIN _OSCOUT VSS Ideal applications for the UR7HCTS2-USB include portable devices, interactive kiosks and industrial / custom displays with integrated touch screens. 36-pin SSOP 18 The universal features of the UR7HCTS2-USB, as implemented in both the system and the sensor interface, reduce the development effort and cost of touch input based systems. The UR7HCTS2USB is available in a 36-pin SSOP package. 36 19 Semtech and ScreenCoder are registered trademarks of Semtech Corporation. All other trademarks belong to their respective owners. Copyright ©2000-2002 Semtech Corporation UR7HCTS2-USB data sheet v1.06 2002-12 1 www.semtech.com D+ D_RB _TOUCH XR2/SE2 YB2/SW2 YT2/NE2 XL2/NW2 N/C N/C USBV N/C N/C _WR5/WR4-8 XL1/NW1 YT1/NE1 YB1/SW1 XR1/SE1 ORDERING CODE Package Options 36-pin plastic SSOP Pitch 0.8 mm TA = -20° C to +85° C UR7HCTS2-USB-DR Other Materials ScreenCoder® USB eval. kit Type Evaluation kit Order number EVK7-TS2-USB BLOCK DIAGRAM FOR THE UR7HCTS2-USB Power Management Section Switch Interface Power -On Reset Right Button Drivers for Touch Screen Touch Panel Interface 4 Sense Line(s) 16-Bit Timer Sensor Interface Oscillator Circuit USB Communication Interface D+ DUSBV OSCIN _OSCOUT Copyright ©2000-2002 Semtech Corporation UR7HCTS2-USB data sheet v1.06 2002-12 2 www.semtech.com FUNCTIONAL DESCRIPTION PIN DEFINITIONS The UR7HCTS2-USB consists functionally of five major sections (see the Functional Diagram on Page 2). These are the Sensor Interface, the Power Management Section, the 16-Bit Timer, the Oscillator Circuit and the USB Interface. Mnemonic Pin # Type Name and Function Power VDD VSS, VSS2 15 18, 14 P P Power supply Ground OSCILLATOR This IC has a built-in oscillator circuit capable of operations with an external 6.00 MHz clock source, such as a ceramic resonator with built-in load capacitors. POWER MANAGEMENT According to the USB specification, if there is no activity of the USB port for 3 ms, the system is considered to be in a suspended state. The UR7HCTS2-USB, on detecting that the system is in suspend, checks the state of the touch screen and the right button. If there is no touch pressure detected and no button pressed, the UR7HCTS2-USB enters the suspended state. In suspend, the IC fully complies with the USB specification for power consumption, dissipating current only in the USB-mandated pull-up for device identification. The IC supports remote wake-up to conserve power. If the system relies on the device to perform wake-up, the IC sends a resume message to the system when there is activity on the touch screen or button. Reset _RESET 13 I Reset: apply 0V to provide orderly start-up Oscillator _OSCOUT 17 O OSCIN 16 I Oscillator output: open for external clock input or other side of the ceramic resonator with built-in load capacitors Oscillator input: external clock input or one side of the ceramic resonator with built-in load capacitors USB DD+ USBV 35 36 26 I/O I/O O USB D- Line USB D+ Line USB reference voltage output: output pin for pulling up a D- line with a 1.5K Ohm external resistor _RB _TOUCH _WR5/WR4-8 34 33 23 I/O (nd) I/O I/O SENSE_AD SENSE_DRV SXL/NW_AD SXR/SE_AD SYB/SW_AD SYT/NE_AD VREF XL1/NW1 XL2/NW2 XR1/SE1 XR2/SE2 YB1/SW1 YB2/SW2 YT1/NE1 YT2/NE2 9 8 4 7 6 5 12 22 29 19 32 20 31 21 30 AI I/O AI AI AI AI AI I/O I/O I/O I/O I/O I/O I/O I/O Right button: active low, strobed sampling 5-wire: Touch Detection 4/8-wire: Leave open (has internal pull-up); 5-wire: Tie to ground 5-wire: Sense A/D 5-wire: Sense drive 4/8-wire: Sense line for X Left. 5-wire: Northwest 4/8-wire: Sense line for X Right. 5-wire: Southeast 4/8-wire: Sense line for Y Bottom. 5-wire: Southwest 4/8-wire: Sense line for Y Top. 5-wire: Northeast Reference voltage for built-in A/D 4/8-wire: Sense drive X Left. 5-wire: Northwest 4/8-wire: Sense drive X Left. 5-wire: Northwest 4/8-wire: Sense drive X Right. 5-wire: Southeast 4/8-wire: Sense drive X Right. 5-wire: Southeast 4/8-wire: Sense drive Y Bottom. 5-wire: Southwest 4/8-wire: Sense drive Y Bottom. 5-wire: Southwest 4/8-wire: Sense drive Y Top. 5-wire: Northeast 4/8-wire: Sense drive Y Top. 5-wire: Northeast Touch screen Reserved N/C 1-3, 10, 11, 24, 25, 27, 28 Reserved Note: An underscore before a pin mnemonic denotes an active low signal. Pin Types Legend: I=Input; O=Output; I/O=Input or Output; P=Power; Al= Analog Input; I/O (nd) open drain USB FUNCTIONALITY If the system does not allow remote wake-up, the UR7HCTS2-USB does not send resume messages to the system when it is awakened by activity on the touch screen or button. The UR7HCTS2-USB is a low-speed USB device with remote wake-up capability. The IC asks the system to send report requests every 10ms according to the USB specification for a low speed device. Copyright ©2000-2002 Semtech Corporation UR7HCTS2-USB data sheet v1.06 2002-12 3 The UR7HCTS2-USB describes itself as a pointer, and provides absolute position data to the system. www.semtech.com TOUCH SCREEN SENSOR INTERFACE The UR7HCTS2-USB can acquire data from any 4-wire, 5-wire, or 8-wire resistive touch screen sensors. The sensor interface has the following features: Touch detection The IC periodically checks touch pressure applied to the panel. If there is no touch, the IC does not perform measurements and does not send data to system. When touch pressure is detected, the IC further qualifies and determines the amount of pressure. Semtech’s proprietary, patent-pending touch detection algorithm performs this test very quickly, accommodating sensors with various plate-to-plate capacitances. Touch Measurement (4/8-wire sensors) Position information is only collected if it has been determined that the touch pressure is sufficient for an accurate reading. To obtain position information from the resistive touch screen sensor, the UR7HCTS2-USB uses four internal drivers (two pins for each driver) and four sense lines. During sampling, the drivers of the X-axis are activated by setting one X-drive high and the other X-drive low. The drivers for Y-axis are set floating. This action produces a voltage gradient across the touch screen's surface in the X direction. The internal A/D measures both the voltage across the activated X-plane and the voltage potential between the planes. Next, the drivers for the Yaxis are activated while the drivers for X-axis are set floating. Again, the internal A/D measures both voltage across the activated plane and potential between the planes. The X and Y absolute position is obtained from these four A/D measurements. The IC keeps measuring the touch pressure even while the positioning data is acquired. If insufficient touch pressure is detected during sampling of the position, the current data set is rejected. Touch Measurement (5-wire sensors) Position information is collected only if the touch pressure is sufficient for an accurate reading. The 5-wire touch screen has two panels. One is the resistive panel for supplying the voltage gradient. The other is the conductive panel used to get the touch voltage. To obtain position information from the resistive touch screen sensor, the UR7HCTS2-USB uses four internal drivers (three pins for each driver) and one sense line. During sampling, the drivers of the X-axis are activated by setting one X-drive high and the other X-drive low. The sense plane is set floating. This action produces a voltage gradient across the touch screen's surface in the X direction. The internal A/D measures both the voltage across the activated X-plane and the voltage potential between the planes. Next, the drivers for the Y-axis are activated. Again, the internal A/D measures both voltage across the activated plane and potential between the planes. The X and Y absolute position is obtained from these A/D measurements. Touch algorithm Due to vibration and electrical noise, the raw data can not be used directly. Internal data processing delivers consistent position accuracy and quick touch response. Resolution The UR7HCTS2-USB uses a built-in A/D converter to get the touch position. The maximum touch screen resolution is 1000 points per axis. Resolution varies somewhat for different touch screen sensors, due to voltage droop on connecting wires. Touch screens from different makers Operating parameters for the touch screens from different manufacturers vary depending on the size of the sensor, material it is made from, and mechanical construction. The UR7HCTS2-USB takes these properties into account, and adjusts automatically for plate-to-plate capacitance, intrinsic plate resistances, etc. Buttons The UR7HCTS2-USB implements the equivalent of left and right mouse buttons. Left button press is reported when there is touch pressure on the panel, and then released when the pressure stops. The right button is implemented as a switch using pin 34. Copyright ©2000-2002 Semtech Corporation UR7HCTS2-USB data sheet v1.06 2002-12 4 www.semtech.com SAMPLE SCHEMATIC WITH 4/8-WIRE SENSOR RN1 4.7K See Notes 8 SXR S YB SYT SXL 6 7 SW1 GND 1 2 3 4 5 6 7 8 N/C D+ N/C D- XR2 N/C SXL RB SYT XL2 YT2 YB2 N/C U1 UR7HCTS2-USB N/C N/C N/C USBV 36 Pin DR SYB SXR RVSD4 RVSD5 RVSD7 RVSD6 VREF OSCIN VDD VSS2 XR1 YB1 YT1 XL1 WR5/WR4 N/C OSCOUT RESET VSS 35 36 U3 STF203-33 DI/O DI/O VBUS GND DI/O DI/O 6 5 4 33 34 32 31 29 30 28 27 C7 26 25 0.1uF GND 24 22 23 21 19 20 1 2 3 GND 2 3 J1 1 4 VDD GND C2 10uF SHIELD Mounting holes 6 RIGHT BUTTON XL YT YB XR VDD 10 9 U2 11 18 17 16 15 14 13 12 1 6.00MHz Y1 TC54VC4502ECB C1 0.1uF GND Connect drive and sense lines together for the 4-wire sensor. Y1 == 6.00 MHz ceramic resonator with built-in load capacitors: AVX PBRC-6.00BR or Murata CSTC6.00MG or equivalent. STF203-33 is a USB upstream port filter and protection chip. 5 DRV_XL DRV_YT DRV_YB DRV_XR SENSE_XL SENSE_YT SENSE_YB SENSE_XR C3 C4 10nF +/-10% X7R 10nF +/-10% X7R C5 10nF +/-10% X7R C6 10nF +/-10% X7R GND 4 5 UR7HCTS2-USB is hardware compatible with the UR7HCTS2-U860. Customers using the UR7HCTS2-U860 can use their existing design. Notes: 2 3 www.semtech.com 5 Copyright ©2000-2002 Semtech Corporation UR7HCTS2-USB data sheet v1.06 2002-12 2 3 1 SAMPLE SCHEMATIC WITH 5-WIRE SENSOR 1 2 3 4 5 8 7 6 5 GND NC NC P5 P1 P2 P3 P4 U2 1 2 3 4 C4 GND NW NE SW SE SENSE Q1 MOSFET_N 1 R1 4.7K C1 2 3 10nF GND 4 5 6 7 8 10 9 U3 11 18 17 16 15 14 13 12 1 6.00MHz Y1 TC54VC4502ECB VDD 0.1uF GND P11/TXD/D+ P10/RXD/D- RVSD1 RVSD2 RB SE2 TOUCH RVSD8 RVSD9 NW2 NE2 SW2 AD_NW RVSD3 U1 36 Pin DR UR7HCTS2-USB AD_NE AD_SW AD_SE SENSE_DRV SENSE_AD RVSD4 USBV WR5/WR4 RVSD5 VSS2 NW1 RVSD7 VDD NE1 VREF OSCIN SE1 SW1 RVSD6 OSCOUT RESET VSS SW1 1 2 3 RIGHT BUTTON U3 STF203-33 GND 36 DI/O DI/O VBUS GND DI/O DI/O 35 C3 GND 0.1uF 6 5 4 34 32 33 31 30 28 29 27 26 25 24 23 22 20 21 19 2 3 GND J1 1 4 10uF C2 VDD SHIELD GND Mounting holes 6 J2 CON5 GND SMDAXXC-5 NOTES: The UR7HCTS2-USB in 5-wire mode is hardware compatible with the UR7HCTS2-U560 except for pin 23. For the UR7HCTS2-USB in 5-wire mode, pin 23 must be connected to ground; for the UR7HCTS2-U560, pin 23 is not connected. Y1 == 6.00 MHz ceramic resonator with built-in load capacitors: AVX PBRC-6.00BR or Murata CSTC6.00MG or equivalent. SMDAXXC-5 is optional for protection. STF203-33 is a USB upstream port filter and protection chip. 5 www.semtech.com 6 Copyright ©2000-2002 Semtech Corporation UR7HCTS2-USB data sheet v1.06 2002-12 2 3 SCHEMATIC FOR EVALUATION KIT J4 CON4 4-wire Touchscreen Connector RN1 4.7K J3 CON16C +/-10% X7R +/-10% X7R +/-10% X7R +/-10% X7R 4 5 6 S YB 7 8 SXR 9 10 11 12 13 14 15 16 GND GND Q1 SW1 GND RIGHT BUTTON XL YT YB XR VDD TEST_POINT SH5 1 2 3 4 5 6 7 8 9 10 12 11 U2 13 14 1 15 16 18 17 NC D+ D- TOUCH5W RB XR2/SE2 NC SXL/AD_NW YB2/SW2 NC NC XL2/NW2 YT2/NE2 SYT/AD_NE SXR/AD_SE SYB/AD_SW NC U1 36 Pin DR NC USBV VDD VSS2 YT1/NE1 XL1/NW1 WR5/WR4 UR7HCTS2-USB SENSE_DRV SENSE_AD NC NC VREF OSCIN XR1/SE1 YB1/SW1 NC OSCOUT RESET VSS NOTES: USB Out, 6.00 MHz 36 35 34 33 31 32 29 30 28 27 GND 4 5 6 6 5 4 C3 26 25 GND GND 0.1uF 23 24 22 20 21 19 U4 STF202-30 D2out D2in D1out D1in Vss Vbus U3 STF203-33 CON2 J6 DI/O DI/O VBUS GND DI/O DI/O 1 2 Close the switch only when using 5-wire touch screen Different Touch Screens. 4/8/5-wire Both U3 and U4 are USB protection chips. Use either one for the application. TEST_POINT TEST_POINT SH7 SH6 6.00MHz Y1 TC54VC4502ECB C1 GND 0.1uF VDD GND 3 2 1 1 2 3 GND 2 3 J7 1 4 GND VDD C2 10uF Mounting holes SHIELD 6 J5 CON8 J1 R1 4.7K BSS138 GND CON16C Short for 4 wire 8 7 6 5 4 3 2 1 8-wire Touchscreen Connector C5 C6 C7 C8 GND 10nF C4 Short for 8 wire J2 CON16C 10nF10nF10nF10nF JP2 CON_1X5 5-WIRE CONNECTORS 5 www.semtech.com 7 Copyright ©2000-2002 Semtech Corporation UR7HCTS2-USB data sheet v1.06 2002-12 2 3 3 S YT 1 2 3 4 5 6 7 8 SXL 5 4 3 2 1 Short for 5 wire JP1 CON_1X5 SENSE 2 1 16 15 14 13 12 11 10 9 SW NW SENSE SE NE SE SW NE NW 1 2 3 4 5 NE NW SENSE SW SE 1 2 3 4 5 6 7 8 1 2 3 4 16 15 14 13 12 11 10 9 1 2 3 4 5 6 7 8 LAYOUT FOR EVALUATION KIT BOARD Copyright ©2000-2002 Semtech Corporation UR7HCTS2-USB data sheet v1.06 2002-12 8 www.semtech.com MECHANICAL INFORMATION FOR DR (36-PIN SSOP) PACKAGE e 1 36 D y b 18 19 36-pin SSOP Plastic E Detail F c A2 A L F A1 HE L1 I2 Recommended Mount Pad b2 Symbol e A A1 A2 b c D E e HE L L1 y e1 b2 e1 I2 Copyright ©2000-2002 Semtech Corporation UR7HCTS2-USB data sheet v1.06 2002-12 9 Dimension in Millimeters Min Nom Max – – 2.4 0.05 – – – 2.0 – 0.35 0.4 0.5 0.13 0.15 0.2 14.8 15.0 15.2 8.2 8.4 8.6 – 0.8 – 11.63 11.93 12.23 0.3 0.5 0.7 – 1.765 – – – 0.15 0° – 10° – 0.5 – – 11.43 – – 1.27 – www.semtech.com ELECTRICAL SPECIFICATIONS Absolute Maximum Ratings Ratings Supply voltage Input voltage Current drain per pin (not including VSS or VDD) Operating temperature UR7HCTS2-USB Storage temperature range ESD rating (human body model) Symbol VDD VIN I Value -0.3 to 7.0 VSS -0.3 to VDD +0.3 20 Unit V V mA TA TLOW to THIGH -20 to +85 -40 to +125 TBD °C °C °C kV TSTG VESD DC Electrical Characteristics, Temperature range = TLOW to THIGH unless otherwise noted) Characteristic Symbol Min Typ Max Supply voltage 4.4 5.0 5.5 Output voltage (10 µA load) VOH VDD–0.1 VOL 0.1 Input high voltage VIH 0.8 x VDD VDD Input low voltage VIL VSS 0.2 x VDD Input current IIN +/- 10 Supply current (VDD=5.0 VDC+/-10%, VSS=0) IDD 3.0 TBD Unit V V V V µA mA Control Timing (Vdd=5.0 Vdc +/-10%, VSS=0 VDC, Temperature range = TLOW to THIGH unless otherwise noted) Characteristic Symbol Min Typ Max Unit Frequency of operation Crystal option fosc 6.0 MHz External clock option fosc 6.0 MHz Copyright ©2000-2002 Semtech Corporation UR7HCTS2-USB data sheet v1.06 2002-12 10 www.semtech.com This page intentionally left blank Copyright ©2000-2002 Semtech Corporation UR7HCTS2-USB data sheet v1.06 2002-12 11 www.semtech.com For sales information and product literature, contact: Semtech Corporation Human Interface Device (HID) and System Management Division 200 Flynn Road Camarillo, CA 93012-8790 [email protected] http://www.semtech.com/ (805)498-2111 Telephone (805)498-3804 Fax Copyright ©2000-2002 Semtech Corporation. All rights reserved. Semtech and ScreenCoder are registered trademarks of Semtech Corporation. All other trademarks belong to their respective owners. LIMITED LICENSE GRANTED; NO WARRANTIES MADE This specification is provided "as is" with no warranties whatsoever including any warranty of merchantability, fitness for any particular purpose, or any warranty otherwise arising out of any proposal, specification or sample. Any suggestions or comments by Semtech regarding use of this product are opinion only and Semtech makes no warranty as to results to be obtained in any specific application. A license is hereby granted to reproduce and distribute this specification for internal use only. No other license, expressed or implied to any other intellectual property rights is granted or intended hereby. Authors of this specification disclaim any liability, including liability for infringement of proprietary rights, relating to the implementation of information in this specification. Authors of this specification also do not warrant or represent that such implementation(s) will not infringe such rights. Copyright ©2000-2002 Semtech Corporation UR7HCTS2-USB data sheet v1.06 2002-12 12 www.semtech.com