
1
8
9
32
25
24
16
17
SYB
SXR
XPWRS
RSVD1
VREF
RESET
VSS2
VDD
LB
XR2
YB2
YT2
XL2
HDAT
XDAT
XCLK
O
O
V
X
Y
Y
X
H
R
R
R
R
R
P
S
S
Portable systems
Notebooks and Laptops
Interactive Kiosks
Touch-enabled monitors
The ScreenCoder
TM
PS2 is a high-
performance IC that interfaces any
4 or 8-wire resistive touch screen
to the standard PS/2 mouse port.
Low-power and tiny, the single IC
is ideal for portable systems, web
phones and interactive kiosks. It
offers an advanced algorithm for
enhanced motion control as well as
an extra port for hot-plug
connection of an external PS/2
pointing device. Both the touch
screen and the external device can
be operated concurrently without
any penalty.
The UR7HCTS2-P840 is equipped
with a special command protocol
that enables the touch screen to
operate in either relative (mouse-
like) or absolute positioning mode.
Because the IC interfaces via the
PS/2 mouse port, it can utilize any
standard mouse driver when
operating in relative mode. For
absolute positioning, offers a high-
functionality driver which includes
inking capabilities.
Mice connected to the
ScreenCoder
TM
PS2 external mouse
port will always act in relative
mode, even if the touch screen is
operating in the absolute mode.
The PS/2 communication channel
is bi-directional at 10 kbps.
The ScreenCoder
TM
PS2 offers built-
in A/D. Touch detection and
motion are handled in firmware,
and no digitizer is required. The
cost-effective solution requires few
external components, allowing for
a simple and real estate saving
implementation.
Embedded touch screen and
external pointing device can
operate concurrently with no
performance penalty
Supports both absolute and
relative (mouse-like) modes of
operation
For relative mode, no special
drivers are needed; high-
functionality driver available for
absolute mode
Supports all commands defined
in the IBM PS/2 Mouse
Communication Protocol, as
well as Semtech’s extended PS/2
communication protocol with
absolute positioning support
Available in a low-profile 32-pin
LQFP package
Few external components required
Controller & digitizer in a single IC;
no need for external A/D
Interfaces ANY 4- or 8-wire
resistive touch screen to standard
PS/2 mouse port; regardless of
size, material or vendor
High-performance IC offers
accurate cursor control due to
advanced algorithms
Low-power consumption, due to
sophisticated power management
states, ideal for battery-operated
systems
Highly resistant to RF & other
noise sources
Enables hot-plug connection of
an external pointing device
Wheelmouse functionality is
supported in the external pointing
device
Other interfaces available
APPLICATIONS
PIN ASSIGNMENTS
DESCRIPTION
FEATURES
ScreenCoder
TM
UR7HCTS2-P840
High-Performance, Low Power PS/2
Touch Screen Controller/Digitizer
ScreenCoder and MouseCoder are trademarks of
Semtech Corporation. All other trademarks belong
to their respective companies.
Copyright 1999-2001 Semtech Corporation
DOC7-TS2-P840-DS-106
www.semtech.com
1
HID & SYSTEM MANAGEMENT PRODUCTS, MOUSECODER
TM
FAMILY