Datasheet UR7HCTS2-U860-DR Datasheet (Semtech)

ScreenCoderTMUR7HCTS2-U860

High-Performance USB

Touch Screen Controller / Digitizer

ScreenCoder, MouseCoder are trademarks of
Semtech Corp. All other trademarks belong to
their respective companies.

Copyright Semtech 2000-2001
DOC7-TS2-U860-DS-101

www.semtech.com

1

HID & SYSTEM MANAGEMENT PRODUCTS, MOUSECODERTMFAMILY

DESCRIPTION FEATURES

• Handhelds/Notebooks

• Portable Devices

• Interactive Kiosks

• Industrial/Custom Touch Screens

The ScreenCoderTMUSB IC is the
first single IC that seamlessly
interfaces ANY 4- or 8-wire
resistive touch screen to a USB­equipped 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- 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 digitizers, the
ScreenCoderTMUSB 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 application for the
ScreenCoderTMUSB include
portable devices, interactive kiosks
and industrial / custom displays
with integrated touch screens.

The universal features of the
ScreenCoderTMUSB, as
implemented in both the system
and the sensor interface, reduce
the development effort and cost of
touch input based systems. The
ScreenCoderTMUSB 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 including Windows®
98, Me and 2000

• Convienent calibration applet
offered free of charge

• Uses slim 36-pin, SSOP package

• Customized versions available

• Controller & digitizer in a single IC

• Interfaces the system via USB

• Works with ANY 4- 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

APPLICATIONS

PIN ASSIGNMENTS

RSVD1
RSVD2
RSVD3

RSVD4

RSVD5
RSVD6

RSVD7

_RESET

OSCIN

_OSCOUT

1

SXL
SYT
SYB

SXR

36-pin SSOP

VREF

VSS2

VDD

VSS

18

36

D+
D-

_RB

RSVD13
XR2
YB2
YT2
XL2
RSVD12
RSVD11
USBV
RSVD10
RSVD9
RSVD8
XL1
YT1
YB1
XR1

19

ORDERING CODE

Copyright Semtech 2000-2001
DOC7-TS2-U860-DS-101

www.semtech.com

2

Package Options Pitch in mm’s TA=-20° C to +85° C

36-pin, Plastic SSOP 0.8mm UR7HCTS2-U860-DR

Other Materials Type Order number

ScreenCoderTMUSB Eval Kit Evaluation Kit EVK7-TS2-U860-XXX

Power

Management

Section

Power -On Reset

16-Bit Timer

Oscillator Circuit

Sensor Interface

Switch Interface

Touch Panel

Interface

USB

Communication

Interface

OOSSCCIINN __OOSSCCOOUUTT

RRiigghhtt BBuuttttoonn

DDrriivveerrss ffoorr TToouucchh

SSccrreeeenn

SSeennssee LLiinneess

4

4

DD++

DD--

BLOCK DIAGRAM FOR THE UR7HCTS2-U860

FUNCTIONAL DESCRIPTION PIN DEFINITIONS

Copyright Semtech 2000-2001
DOC7-TS2-U860-DS-101

www.semtech.com

3

Mnemonic Pin # Type Name and Function
Power:

VDD 15 P Power Supply
VSS 14,18 P Ground

3.3V 22 P USB Reference Voltage Out

_Reset 13

I Reset

Oscillators:

OSCI 16 I Oscillator Input
OSCO 17 O Oscillator Output

USB:

D- 35 I/O USB D- Line
D+ 36 I/O USB D+ Line

Touch
Screen:

XR1, XR2 19,32 I/O Touch Screen Right Drive Pins
YB1, YB2 31,20 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
SXR 7 Al Touch Screen Sense Pin: for X Right
SYB 6 Al Touch Screen Sense Pin: for Y Bottom
SYT 5 Al Touch Screen Sense Pin: for Y Top
SXL 4 Al Touch Screen Sense Pin: for X Left
VREF 12 Al Voltage Reference for A/D Converter
SOUT 23 O Output control data to A/D Converter
_RB 34 I Mouse Right Button
RDVD1-13 1-3,8-11 I/O Reserved for future use

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.

If the system does not allow remote wake-up, the ScreenCoderTMUSB will
not send resume messages to the system when it is awoken by activity on
the touch screen or button.

This IC has a built-in Oscillator
circuit capable of operations with
an external 6.00 MHz Clock source,
or a Ceramic Resonator (preferably
with built-in Load Capacitors) or a
Crystal with external 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
ScreenCoderTMUSB IC, on
detecting that the system is in
suspend, will check the state of the
touch screen and the right button.
If there is no touch pressure
detected or no button pressed, the
ScreenCoderTMUSB enters into the
suspended state. In suspend the
IC fully complies with the USB
specification for the power
consumption, dissipating current
only in the USB-mandated pull-up
for the device identification.

Another technique the IC uses to
conserve power is called remote
wake-up. If the system relies on the
device to perform wake-up, the IC
will send a resume message to the
system when there is activity on the
touch screen or button.

POWER MANAGEMENT

POWER MANAGEMENT (CON’T)

TOUCH SCREEN SENSOR INTERFACE

Copyright Semtech 2000-2001
DOC7-TS2-U860-DS-101

www.semtech.com

4

The ScreenCoder

TM

USB can acquire data from any 4- 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 will not perform
measurements and will 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 ScreenCoderTMUSB 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 will be 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 ScreenCoderTMUSB uses a built-in A/D converter to get the touch position. The maximum touch screen
resolution is 1000 points per direction. 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 ScreenCoderTMUSB takes these properties into
account, and adjusts automatically for plate-to-plate capacitance, intrinsic plate resistances, etc.

Buttons

The ScreenCoderTMUSB implements both left and right buttons, however, there is no physical left button. Left
button press is reported when there is touch pressure on the panel. The left button is released when there is no
pressure on the panel. The right button is a physical button, and can be used individually.

Offset Part Size Value Description

Device Descriptor

0 bLength 1 0x12 Numeric expression specifying the size of

device descriptor

1 bDescriptonType 1 0x01 Device descriptor type

2 bcdUSB 2 0x0100 USB HID spec release number 01.00

3 bDeviceClass 1 0x00 Class code
4 bDeviceSubClass 1 0x00 Sub class code
5 bDeviceProtocol 1 0x00 Protocol code
6 bMaxPacketSize0 1 0x08 Maximum packet size for EP0
8 idVendor 2 0x047A USAR's vendor ID
10 idProduct 2 0x0004 USAR ScreenCoderTMUSB Product ID
12 bcdDevice 2 0x0061 Device release number
14 iManufacture 1 0x04 Index of string descriptor describing

manufacturer

15 iProduct 1 0x0E Index of string descriptor describing

product

16 iSerialNumber 1 0x00 Index of String descriptor describing

serial number

17 bNum- 1 0x01 Number of possible configurations

Configuration Descriptor

0 bLength 1 0x09 Size of configuration descriptor in bytes
1 bDescriptorType 1 0x02 Configuration (assigned by USB)
2 wTotalLength 2 0x0022 Total length of data returned for this
4 bNumInterface 1 0x01 Number of interfaces supported by this

configuration
5 bConfigurationValue1 0x01 Current configuration value
6 iConfiguration 1 0x00 Configuration string descriptor index
7 bmAttribute 1 0xA0 Configuration characteristics - bus

powered, with remote wakeup
8 MaxPower 1 0x32 Maximum power consumption of USB

device 100 mA

Interface Descriptor

0 bLength 1 0x09 Size of Interface descriptor in bytes
1 bDescriptorType 1 0x04 Interface descriptor type
2 bInterfaceNumber 1 0x00 Number of interface
3 bAlternateSetting 1 0x00 Number of alternate setting
4 bNumEndpoints 1 0x01 Number of endpoint
5 bInterfaceClass 1 0x03 Class code (HID)
6 bInterfaceSubClass 1 0x00 Subclass code (nor boot interface

subclass)
7 bInterfaceProtocol 1 0x02 Protocol code = mouse
8 iInterface 1 0x00 Index of string descriptor describing this

interface

HID Descriptor

0 bLength 1 0x09 Size of HID descriptor in byte
1 bDescriptorType 1 0x21 HID descriptor type
2 bcdHID 2 0x0100 HID Spec release number
4 bCountryCode 1 0x00 Hardware target country
5 bNumDescriptor 1 0x01 Number of HID class descriptor follow
6 bDescriptorType 1 0x22 Report descriptor type
7 wDescriptorLength 2 0x0038 Total length of report descriptor

USB FUNCTIONALITY

Copyright Semtech 2000-2001
DOC7-TS2-U860-DS-101

www.semtech.com

5

The ScreenCoderTMUSB is a low­speed USB device with remote
wake-up capability. The IC asks
the system to send report requests
every 10ms according to USB
specification for low speed device.

The ScreenCoderTMUSB describes
itself as a pointer, and provides
absolute position data to the
system.

USB DESCRIPTORS

USB DESCRIPTORS, (CON’T)

Copyright Semtech 2000-2001
DOC7-TS2-U860-DS-101

www.semtech.com

6

Offset Part Size Value Description

Endpoint Descriptor

0 bLength 1 0x07 Size of endpoint descriptor in bytes
1 bDescriptorType 1 0x05 Endpoint descriptor type
2 bEndpointAddress 1 0x81 Endpoint address (IN, Endpoint 1)
3 bmAttribute 1 0x03 Endpoint's attribute (interrupt)
4 WMaxPacketSize 2 0x0005 Maximum packet size
6 BInterval 1 0x0A Interval for polling (poll every 10 ms)

String Descriptor

1 bLength 1 0x04 Length of string description in bytes
2 bDescriptorType 1 0x03 Descriptor type = String
3 bString 2 0x0904 LangID code = English
5 bLength 1 0x0A Length of string descriptor
6 bDescriptorType 1 0x03 Descriptor Type = String
7 bString 8 ‘U’,0,’S’, Manufacturer

0,’A’,0,

’R’,0
15 bLength 1 0x3A Length of string descriptor
16 bDescriptorType 1 0x03 Descriptor type = String
17 bString 20 ‘S’,0,’c’ “ScreenCoderTM UR7HCTS2-U860”

0,’r’,0,

’e’,0,etc.

Offset Data Mnemonic Value

Report Descriptor

0 05 01 Usage Page Generic Desktop
2 09 01 Usage Pointer
4 A1 01 Collection Application
6 09 01 Usage Pointer
8 A1 00 Collection Physical
10 05 09 Usage page Buttons
12 19 01 Usage Minimum 1
14 29 03 Usage Maximum 3
16 15 00 Logical Minimum 0
18 25 01 Logical Maximum 1
20 95 03 Report Count 3
22 75 01 Report Size 1
24 81 02 Input Variable
26 95 01 Report Count 1
28 75 05 Report Size 5
30 81 01 Input Constant
32 05 01 Usage Page Generic Desktop
34 09 30 Usage X
36 09, 31 Usage Y
38 15, 00 Logical Maximum 0
40 26, FF 7F Usage Maximum 15 bits 7FFF
43 35, 00 Physical Minimum 0
45 46, FF 7F Physical Maximum 15 bits 7FFF
48 75, 10 Report Size 16 bits
50 95, 02 Report Count 2
52 81, 02 Input Variable
54 C0 End Collection
55 C0 End Collection

SUGGESTED INTERFACING FOR THE SCREENCODERTMUSB UR7HCTS2-U860-DR

Copyright Semtech 2000-2001
DOC7-TS2-U860-DS-101

www.semtech.com

7

Y1 == 6.00 MHz Ceramic Resonator with Built-in Load Capacitors.

SHIEL D

Mounting holes

NOTES:

See Not es

Connect Drive and Sense lines together for the 4-wire sensor

Crystals can NOT be used.

U860 == USB Out, 6.00 MHz, 8/4-wire, Model0

ScreenCoder(TM) USB UR7HCTS2-U860

(C)2000 USAR, A Semtech Company

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

10uF

C7

0.1uF

RN1

4.7K

1

3

5

7 8

6

4

2

Y1

6.00MHz

SW1

RIGHT BUTTON

R1 30

U2

TC54VC4502ECB

1

23

C1

0.1uF

C3

10nF

+/-10% X7R

R2 30

C4

10nF

+/-10% X7R

UR7HCTS2-U860

1

2

3

4

5

6

7

8

9

101112131415161718

3635343332313029282726

25242322212019

RVSD1

RVSD2

RVSD3

SXL

SYT

SYB

SXR

RVSD4

RVSD5

RVSD6

RVSD7

VREF

RESET

VSS2

VDD

OSCIN

OSCOUT

VSS

D+

D-

RB

RVSD13

XR2

YB2

YT2

XL2

RVSD12

RVSD11

USBV

RVSD10

RVSD9

RVSD8

XL1

YT1

YB1

XR1

J1

12

3 4

5

6

DRV_YB

SENSE_YB

SENSE_XL

DRV_XL

SENSE_XR

DRV_XR

DRV_YT

SENSE_YT

36-pin SSOP

MECHANICAL INFORMATION FOR DR (36-PIN SSOP) PACKAGE

Copyright Semtech 2000-2001
DOC7-TS2-U860-DS-101

www.semtech.com

8

36 19

E

F

HE

L1

A

A

2 A1

1

18

D

L

e

y

b

c

Recommended Mounting Pad

Symbol

e1

e

b2

I2

Dimension in Millimeters

Min Nom Max

A
A1
A

b

c
D
E

e

H

L

L

y

–

.050

2

–

.350
.130
.814
.28

–

.6311

E

.30

–

1

–

–
–

.02
.40
.150
.015
.48
.80
.9311
.50
.7651

–

.42
–
–

.50

.20

.215

.68
–

.2312

.70
–

.150

0° –10°

2

b
e1

I2

–.50–
–

.271

.4311

–

–
–

ELECTRICAL SPECIFICATIONS

Copyright Semtech 2000-2001
DOC7-TS2-U860-DS-101

www.semtech.com

9

Absolute Maximum Ratings
Ratings Symbol Value Unit

Supply Voltage Vdd -0.3 to 7.0 V
Input Voltage Vin Vss -0.3 to Vdd +0.3 V
Current Drain per Pin I 20 mA
(not including Vss or Vdd)
Operating Temperature Ta T low to T high ° C
UR7HCTS2-U860 -20 to +85 ° C
Storage Temperature Range Tstg -40 to +125 ° C

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 µA load) Voh Vdd–0.1 V

Vol 0.1
Input High Voltage Vih 0.8 x Vdd Vdd V
Input Low Voltage Vil Vss 0.2xVdd V
Input Current Iin +/- 10 µA
Supply Current
(Vdd=5.0 Vdc+/-10%, Vss=0) Idd 3.0 TBD mA

Control Timing (Vdd=5.0 Vdc +/-10%, Vss=0 Vdc, Temperature range=T low to T high unless otherwise noted)
Characteristic Symbol Min Typ Max Unit

Frequency of Operation fosc MHz

Crystal Option 6.0
External Clock Option 6.0

SCREENCODERTMUSB UR7HCTS2-U860 BILL OF MATERIALS

Copyright Semtech 2000-2001
DOC7-TS2-U860-DS-101

www.semtech.com

10

UR7HCTS2-U860-DR BOM
Description Quantity Manufacturer Part# Description
Capacitors:

C1, C7 2 Generic Any .1uF Capacitor
C2 1 Generic Any 10uF Capacitor
C3, C4, C5, C6 4 Generic Any 0.01uF Capacitor, 10% X7R or better

Connectors:

J1 1 Generic Any USB Connector

ICs:

U1 1 USAR UR7HCTS2-860 ScreenCoder

TM

Controller

U2 1 TelCom TC54VC2702ECB Low-power Reset Voltage Detector

Resistors:

R1, R2 2 Generic Any 30 Ohms Resistor
R3 1 Generic Any 1.5k Resistor
RN1 1 Generic Any 4x, 4.7k Resistor Network

Resonator:

Y1 1 Panasonic EFO-S6004E5 6.00MHz Ceramic Resonator, w/ built-in Load Caps

Button:

SW1 1 Generic Any Push Button

Revised 10/03/00

Copyright Semtech 2000-2001
DOC7-TS2-U860-DS-101

www.semtech.com

11

Page Left Blank Intentionally

Copyright Semtech 2000-2001
DOC7-TS2-U860-DS-101

www.semtech.com

12

For sales information
and product literature,
contact:

HID & System Mgmt Division
Semtech Corporation
568 Broadway
New York, NY 10012

[e-mail]
http://www.semtech.com

212 226 2042 Telephone
212 226 3215 Telefax

Semtech Western Regional Sales
805-498-2111 Telephone
805-498-3804 Telefax

Semtech Central Regional Sales
972-437-0380 Telephone
972-437-0381 Telefax

Semtech Eastern Regional Sales
203-964-1766 Telephone
203-964-1755 Telefax

Semtech Asia-Pacific Sales Office
[phone] Telephone
[phone] Telefax

Semtech Japan Sales Office
[phone] Telephone
[phone] Telefax

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[phone] Telephone
[phone] Telefax

Northern European Sales Office
[phone] Telephone
[phone] Telefax

Southern European Sales Office
[phone] Telephone
[phone] Telefax

Central European Sales Office
[phone] Telephone
[phone] Telefax

Copyright 2000-2001 Semtech Corporation. All rights reserved.
MouseCoder, ScreenCoder and Self-Power Management are
trademarks of Semtech Corporation. Semtech is a registered
trademark of Semtech Company. All other trademarks belong to
their respective companies.

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.