ur7hcts2-u860 screencoder? usb high-performance usb 4/8-wire touch screen controller / digitizer semtech and screencoder are registered trademarks of semtech corporation. all other trademarks belong to their respective owners. copyright ?2000-2002 semtech corporation ur7hcts2-u860 data sheet v1.03 2002-10-03 www.semtech.com 1 hid & system management products, screencoder? family description features ? handheld pcs (h/pcs) notebook pcs portable devices interactive kiosks industrial/custom touch screens the ur7hcts2-u860 screencoder? usb is the first single ic that seamlessly interfaces any 4-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 4-wire or 8-wire 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 screencoder? 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, non-jittery cursor control. ideal applications for the screencoder? usb include portable devices, interactive kiosks and industrial / custom displays with integrated touch screens. the universal features of the screencoder? usb, as implemented in both the system and the sensor interface, reduce the development effort and cost of touch input based systems. the screencoder? usb is available in a slim, 36-pin ssop package. highly resistant to rf and other noise no digitizer or external a/d necessary fully compliant with usb hid specifications; works with native usb drivers under windows? 98 se, windows? me, windows? 2000, and windows? xp convienent calibration applet offered free of charge uses slim 36-pin, ssop package controller & digitizer in a single ic interfaces the system via usb works with any 4-wire 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 1 18 19 36 rsvd1 rsvd2 rsvd3 sxl syt syb sxr rsvd4 rsvd5 rsvd6 rsvd7 vref _reset vss2 vdd oscin _oscout vss d+ d- _rb rsvd13 xr2 yb2 yt2 xl2 rsvd12 rsvd11 usbv rsvd10 rsvd9 rsvd8 xl1 yt1 yb1 xr1 36-pin ssop applications pin assignments preliminary
ordering code copyright ?2000-2002 semtech corporation ur7hcts2-u860 data sheet v1.03 2002-10-03 www.semtech.com 2 package options pitch ta = -20 c to +85 c 36-pin plastic ssop 0.8 mm ur7hcts2-u860-dr other materials type order number screencoder? usb eval. kit evaluation kit evk7-ts2-u860 power management section power -on reset 16-bit timer oscillator circuit sensor interface switch interface touch panel interface usb communication interface o s c i n _ o s c o u t d r i v e r s f o r t o u c h s c r e e n s e n s e l i n e s 4 4 d+ d- right button usbv block diagram for the ur7hcts2-u860
functional description pin definitions copyright ?2000-2002 semtech corporation ur7hcts2-u860 data sheet v1.03 2002-10-03 www.semtech.com 3 mnemonic pin # type name and function power v dd 15 p power supply v ss , v ss 2 18, 14 p ground reset _reset 13 i reset oscillators oscin 16 i oscillator input _oscout 17 o oscillator output usb: d- 35 i/o usb d- line d+ 36 i/o usb d+ line usbv 26 o usb reference voltage out touch screen xr1, xr2 19, 32 i/o touch screen right drive pins yb1, yb2 20, 31 i/o touch screen bottom drive pins yt1, yt2 21, 30 i/o touch screen top drive pins xl1, xl2 22, 29 i/o touch screen left drive pins sxl 4 al touch screen sense pin: for x left syt 5 al touch screen sense pin: for y top syb 6 al touch screen sense pin: for y bottom sxr 7 al touch screen sense pin: for x right vref 12 al voltage reference for a/d converter _rb 34 i mouse right button reserved rsvd1-13 1-3, reserved for future use 8-11, 23-25, 27, 28, 33 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 the ur7hcts2-u860 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. the screencoder? 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. the screencoder? usb describes itself as a pointer, and provides absolute position data to the system. 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. oscillator 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 screencoder? 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 screencoder? 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. if the system does not allow remote wake-up, the screencoder? usb does not send resume messages to the system when it is awakened by activity on the touch screen or button. power management usb functionality
touch screen sensor interface copyright ?2000-2002 semtech corporation ur7hcts2-u860 data sheet v1.03 2002-10-03 www.semtech.com 4 the screencoder? usb can acquire data from any 4-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 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 screencoder? 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 y- axis 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 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 screencoder? 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 screen 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 screencoder? usb takes these properties into account, and adjusts automatically for plate-to-plate capacitance, intrinsic plate resistances, etc. buttons the screencoder? 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.
suggested interfacing for the screencoder? usb ur7hcts2-u860-dr copyright ?2000-2002 semtech corporation ur7hcts2-u860 data sheet v1.03 2002-10-03 www.semtech.com 5 y1 == 6.00 mhz ceramic resonator with built-i n load capacitors. shield mounting holes notes: connect drive and sense lines together for the 4-wire sensor crystals can not b e used. u860 == usb out, 6.00 mhz, 8/4-wire, model0 syb xl yt syt yb xr sxl sxr gnd vdd gnd gnd gnd vdd gnd r3 1.5k ? c6 10nf +/-10% x7r c5 10nf +/-10% x7r c2 10.0f c7 0.1f rn1 4.7k ? 1 3 5 7 8 6 4 2 y1 6.00mhz sw1 right button r1 30.0 ? u2 tc54vc4502ecb 1 2 3 c1 0.1f c3 10nf +/-10% x7r r2 30.0 ? c4 10nf +/-10% x7r ur7hcts2-u860 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 rvsd1 rvsd2 rvsd3 sxl syt syb sxr rvsd4 rvsd5 rvsd6 rvsd7 vref reset vss2 vdd oscin oscout vss d+ d- rb xr2 yb2 yt2 xl2 rvsd12 rvsd11 usbv rvsd10 rvsd9 rvsd8 xl1 yt1 yb1 xr1 j1 1 2 3 4 5 6 drv_yb sense_yb sense_xl drv_xl sense_xr drv_xr drv_yt sense_yt 36-pin ssop note: connect the drive and sense lines together for a four-wire touch screen sensor note: u2 = reset ic; tc54vc4502ecb (microchip) or equivalent note: y1 = 6.00 mhz ceramic resonator with built-in load capacitors: avx pbrc-6.00br or murata cstc6.00mg or equivalent rvsd13
screencoder? usb ur7hcts2-u860 bill of materials copyright ?2000-2002 semtech corporation ur7hcts2-u860 data sheet v1.03 2002-10-03 www.semtech.com 6 ur7hcts2-u860-dr bom description quantity manufacturer part# description capacitors c1, c7 2 generic any 0.1f capacitor c2 1 generic any 10.0f capacitor c3, c4, c5 4 generic any 0.01f capacitor, 10% x7r or better c6 connectors j1 1 generic any usb connector ics u1 1 semtech ur7hcts2-u860 screencoder? encoder u2 1 microchip tc54vc2702ecb low-power reset voltage detector resistors r1, r2 2 generic any 30.0 ? resistor r3 1 generic any 1.5k ? resistor rn1 1 generic any 4 x 4.7k ? resistor network resonator y1 1 avx pbrc-6.00br 6.00 mhz ceramic resonator with or murata cstc6.00mg built-in load capacitors button sw1 1 generic any push button
mechanical information for dr (36-pin ssop) package copyright ?2000-2002 semtech corporation ur7hcts2-u860 data sheet v1.03 2002-10-03 www.semtech.com 7 symbol min nom max a a 2 b c d e l l 1 y dimension in millimeters h e a 1 i 2 ? ? .35 0 .05 0 .13 0 .8 14 .2 8 ? .63 11 .3 0 ? ? ? .27 1 ? ? .0 2 .4 0 .15 0 .0 15 .4 8 .8 0 .93 11 .5 0 .765 1 ? .43 11 ? ? .4 2 ? .5 0 .2 0 .2 15 .6 8 ? .23 12 .7 0 ? .15 0 ? b 2 ?.5 0? ? 0 ?10 e e 1 36 19 18 1 h e e d b e y f a a 2 a 1 l 1 l c e b 2 e 1 i 2 recommended mount pad detail f 36-pin ssop plastic
electrical specifications copyright ?2000-2002 semtech corporation ur7hcts2-u860 data sheet v1.03 2002-10-03 www.semtech.com 8 absolute maximum ratings ratings symbol value unit supply voltage v dd -0.3 to 7.0 v input voltage v in v ss -0.3 to v dd +0.3 v current drain per pin i 20 ma (not including v ss or v dd ) operating temperature t a t low to t high c ur7hcts2-u860 -20 to +85 c storage temperature range t stg -40 to +125 c esd rating (human body model) v esd tbd kv dc electrical characteristics, temperature range = t low to t high unless otherwise noted) characteristic symbol min typ max unit supply voltage 3.0 5.0 5.5 v output voltage (10 a load) v oh v dd ?0.1 v v ol 0.1 input high voltage v ih 0.8 x v dd v dd v input low voltage v il v ss 0.2 x v dd v input current i in +/- 10 a supply current (v dd =5.0 v dc +/-10%, v ss =0) i dd 3.0 tbd ma control timing (vdd=5.0 vdc +/-10%, v ss =0 v dc , temperature range = t low to t high 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-u860 data sheet v1.03 2002-10-03 www.semtech.com 9 page left blank intentionally
copyright ?2000-2002 semtech corporation ur7hcts2-u860 data sheet v1.03 2002-10-03 www.semtech.com 10 for sales information and product literature, contact: semtech corporation human interface device (hid) and system management division 200 flynn road camarillo, ca 93012-8790 sales@semtech.com 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. intellectual property disclaimer 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. 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.
|
