SEMTECH UR7HCTS2-S840

ScreenCoderTM UR7HCTS2-S840
High-Performance, Low Power
Touch Screen Controller/Digitizer
HID & SYSTEM MANAGEMENT PRODUCTS, MOUSECODERTM FAMILY
Unlike simple A/D implementations,
the ScreenCoderTM SPI/Serial does
not require complicated software
drivers and no processing burden
is placed on the CPU. Due to the
IC’s superior data processing and
sampling rate, the ScreenCoderTM
SPI/Serial is ideal for use in systems
requiring handwriting recognition.
Patented-power management
techniques are also implemented
so that the IC only consumes 1uA
of current most of the time, even
with the external mouse connected.
The IC operates at 3 to 5 Volts.
• Touch screen controller / digitizer
in a single, small footprint IC
• Interfaces the system via either
Serial Peripheral Interface (SPI)
and Asynchronous Serial Interface
• Works with any 4- or 8-wire
resistive touch screen, regardless
of size, material or vendor
• Provides high resolution of 1000
points per axis and a sampling
rate of 200Hz
• Accurate, quick touch response
due to advanced sampling
technology and patented
algorithms
• Zero-PowerTM operation — IC
typically consumes less than 1µA
• Highly resistant to RF and other
noise sources
• Uses sophisticated power
management for maximum power
savings
• Offers external PS/2 port for the
hot-plug connection of an external
PS/2 pointing device
• Capable of providing other
features, such as battery
monitoring and GPIO
• PS/2 and USB interfaces available
• Available in small 7mm X 7mm
32-pin LQFP package
APPLICATIONS
• Web Phones
• Portable Systems
• Wireless Internet Appliances
• Handheld PCs (H/PCs)
PIN ASSIGNMENTS
YT2
XL2
RVSD1
XDAT
XCLK
The ScreenCoderTM SPI/Serial is a
touch screen controller and
integrated digitizer IC designed
specifically for RISC-based
systems, such as wireless Internet
appliances. The small, single
footprint IC interfaces the system
via either the Serial Peripheral
Interface (SPI) or Asynchronous
Serial Interface.
FEATURES
_LB
XR2
YB2
DESCRIPTION
24
Features of Semtech’s motion
algorithm include resistance to RF
and other noise which provides
smooth and precise motion control.
The UR7HCTS2-S840 also works
flawlessly with any 4 or 8-wire touch
screen, regardless of size or
manufacturer.
17
25
16
_RTS/_SS
XL1
YT1
_RB
RSVD2
TxD
ISEL/SCLK
SOUT
_PWR_DOWN
SXL
SYT
The cost-effective solution requires
few external components, allowing
for a simple and real estate saving
implementation.
YB1
XR1
VSS
_OSCOUT
OSCIN
LQFP
32
9
1
8
VDD
VSS2
_RESET
SYB
VREF
_CTS/_ATN
XPWRS
SXR
ScreenCoder, MouseCoder and Self-Power
Management are a trademark of Semtech Corp.
All other trademarks belong to their respective
companies.
Copyright Semtech 2000-2001
DOC7-TS2-S840-DS-102
1
www.semtech.com
ORDERING CODE
Package Options
32-pin, Plastic LQFP
Pitch in mm’s
0.8
TA=-20° C to +85° C
UR7HCTS2-S840-FG
Other Materials
ScreenCoderTM SPI/Serial
Type
Evaluation Kit
Order number
EVK7-TS2-S840-XXX
Note 1: XXX= Denotes Revision number
BLOCK DIAGRAM
Left Button
ASI/SPI
Right Button
ASI/SPI
Communication port
Switch Interface
Power Management
Section
Drivers for Touch
Screen
Touch Panel
Interface
Power-On Reset
4
Sense Line
4
Sensor Interface
16 bit Timer
XCLK
8042 Emulation port
Oscillator Circuit
XDAT
OSCIN
Copyright Semtech 2000-2001
DOC7-TS2-S840-DS-102
_OSCOUT
2
www.semtech.com
PIN DEFINITIONS
Mnemonic Pin #
VDD
8
VSS
11
VSS2
7
OSCIN
9
Type
P
P
P
I
_OSCOUT
10
O
_RESET
XCLK
6
17
I
I/O (nd)
XDAT
18
I/O (nd)
_LB
_RB
XR1, XR2
12,
YB1, YB2
13,
YT1, YT1
14,
XL1, XL2
15,
VREF
SXL
SYT
SYB
SXR
_PWR_DOWN
XPWRS
24
25
23
22
21
20
5
31
32
1
2
30
3
I/O (nd)
I/O (nd)
I/O
I/O
I/O
I/O
AI
AI
AI
AI
AI
I
AI
_SS/_RTS
16
I
_ATN/_CTS
4
O
TXD
SCLK/ISEL
SOUT
RSVD1-2
27
28
29
19,26
O
I
I/O
I/O
Name and Function
Power Supply
Ground
Ground
Oscillator Input: external clock input or one
side of the Ceramic Resonator with built-in Load
Capacitors
Oscillator Output: open for external clock
input or other side of the Ceramic Resonator with
built-in Load Capacitors
Reset: apply 0V to provide orderly start-up
External Mouse Clock: PS/2 clock signal from
external mouse; keep open if unused
External Mouse Data: PS/2 data signal from
external mouse; keep open if unused
Left Button: active low
Right Button: active low
Sensor’s Excitation Driver: connect to X Right
Sensor’s Excitation Driver:connect toY Bottom
Sensor’s Excitation Driver:connect to Y Top
Sensor’s Excitation Driver: connect to X Left
Reference Voltage for built-in A/D
Sense line: for X Left
Sense line: for Y Top
Sense line: for Y Bottom
Sense line: for X Right
Hardware Power Down: tie high if unused
External Mouse Power Sense: connect to
switched power plane for the external pointing device
or tie high if external mouse port is used; tie low if
external mouse port is unused
Slave Select / Ready To Send: active low, host
ready to get data
Attention / Clear To Send: active low, request
data transfer
Data Output: Serial mode
Interface Select / SPI Clock: tie low for Serial
Data Output: SPI mode
Reserved: Keep open
Note: An underscore before a pin mnemonic denotes an active low signal.
Pin Types Legend: AI=Analog Input; I=Input; O=Output; I/O=Input or Output;
I/O (nd)=Input or Output with N-channel Open Drain driver
Copyright Semtech 2000-2001
DOC7-TS2-S840-DS-102
3
www.semtech.com
FUNCTIONAL DESCRIPTION
The UR7HCTS2-S840 consists functionally of five major sections (see the Functional Diagram). These are the
Sensor Interface, Power Management section, the 16-Bit Timer, the Oscillator Circuit and the Serial Peripheral
Interface (SPI) and the Asynchronous Serial Interface (Serial). All sections communication with each other and
operate concurrently.
OSCILLATOR
This IC has a built-in Oscillator circuit capable of operations with an external 4.00 MHz Clock source, or a Ceramic
Resonator (preferably with built-in Load Capacitors). Note, that the Crystals can NOT be used. The ScreenCoderTM
SPI/Serial frequently switches its Oscillator OFF and ON in order to operate with the least amount of power
consumption. Due to very high Q, the Crystal-based oscillators have exceedingly long Start-up time and can not
be used with the ScreenCoderTM SPI/Serial .
EXTERNAL PS/2 INTERFACE
There is one external PS/2 port for the connection of standard PS/2 devices, including a Microsoft WheelMouse or
5-Button Mouse. The mouse motion data is sent out in relative format. The external PS/2 port also supports hotplug; users can connect the mouse to the system at any time without rebooting.
POWER MANAGEMENT
The ScreenCoderTM SPI/Serial implements two power management methods: Self-Power ManagementTM and
System-coordinated Power Management.
Self-Power ManagementTM
Self-Power ManagementTM is a method implemented by the IC that, independently of any system intervention,
results in the lowest power consumption possible within the present parameters of its operation. Through SelfPower ManagementTM, the IC is capable of typically operating at only 1uA, independently of the state of the Host
system. Self-Power ManagementTM primarily determines the actual power consumption of the IC. When the host is
in the active state, the IC can still operate most of the time at only 1uA, even when an active external PS/2 device
is attached to it.
Self-Power ManagementTM offers three modes of operation: Stop, Run and Wait. "Stop" mode is the lowest power
consumption mode. In this mode, the oscillator is stopped and the IC consumes only the leakage current. This is
the default mode to which the IC will revert when it is idle. “Wait” mode is entered when the IC is waiting for a
response or continuation of data stream from the PS/2 device. The duration of wait mode is limited to 40ms, within
which time the IC will either receive new data from the PS/2 device or enter “Stop” mode. Typical power
consumption in this mode is several hundred uAs. “Run” mode is entered briefly, only to process an event. The IC
will only remain in this mode when there are pending tasks, such as PS/2 report reception or initialization of the
PS/2 device.
System Request To Send,
Mouse hot plug or Data Packet,
Touch Screen activity,
Button press
Figure 1: Self-Power ManagementTM State
RUN
STOP
1s of inactivity
Copyright Semtech 2000-2001
DOC7-TS2-S840-DS-102
4
www.semtech.com
POWER MANAGEMENT (CON’T)
System-coordinated Power
Management
Figure 2: System-coordinated Power Management
Normal Operation State:
Critical Suspend
In normal operation state, both the
_PWR_DOWN and XPWRS pins are
in high state. The ScreenCoderTM
SPI/Serial operations are controlled
by Self-Power ManagementTM.
_PWR_DOWN=0
_PWR_DOWN=0
_PWR_DOWN=1
and XPWRS=0
_PWR_DOWN=1
and XPWRS=1
Critical Suspend:
At any time, the Host may negate
the _PWR_DOWN pin in order to
force the ScreenCoderTM SPI/Serial
into a "critical suspend" mode. This
signal can be activated (driven low)
due to specific conditions of the
Host's operations (for example, a
discharged battery), or due to
actions of the Operating System or
BIOS.
During the "critical suspend", the
ScreenCoderTM SPI/Serial will shut
down all of the pointing activities.
External PS/2 power down:
The ScreenCoderTM SPI/Serial
monitors the state of the power
supply rail for the external PS/2
pointing device through the XPWRS
pin. If the IC senses that the external
PS/2 device has been powereddown by the host, it will actively
eliminate shot-through current in the
input buffers for the clock and data
lines by driving both low.
Ext Mouse
power down
_PWR_DOWN=1
and XPWRS=0
Normal State
_PWR_DOWN=1
and XPWRS=1
TOUCH SCREEN SENSOR INTERFACE
The ScreenCoderTM SPI/Serial can acquire data from any four- or eight-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.
The ScreenCoderTM SPI/Serial will reinitialize the external PS/2 pointing
device when the power to the
external PS/2 port is restored.
Copyright Semtech 2000-2001
DOC7-TS2-S840-DS-102
5
www.semtech.com
TOUCH SCREEN SENSOR INTERFACE (CON’T)
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 ScreenCoderTM SPI/Serial 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 ScreenCoderTM SPI/Serial uses a built-in A/D converter to get the touch position. The maximum absolute
position resolution is 1000 points per direction. Resolution varies somewhat for different touch screen sensors, due
to voltage droop on connecting wires and sensor’s mechanical construction.
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 ScreenCoderTM SPI/Serial takes these properties into
account, and adjusts automatically for plate-to-plate capacitance, intrinsic plate resistances, etc.
Touch-screen's coordinates
The zero point for the touchscreen is at the left upper corner. See the diagram
to the right.
(0,0)
X
Buttons
The ScreenCoderTM SPI/Serial implements left and right buttons. The buttons
information is combined with external mouse's buttons information when it is
sent to the system. Typically, the buttons are not used, they are provided as a
development aid.
Y
Copyright Semtech 2000-2001
DOC7-TS2-S840-DS-102
6
www.semtech.com
SERIAL PERIPHERAL INTERFACE (SPI) AND ASYNCHRONOUS SERIAL INTERFACE (SERIAL)
The ScreenCoderTM SPI/Serial
supports either Serial Peripheral
Interface (SPI) or Asynchronous
Serial Interface (Serial)
communication based on the
power-up setting of the ISEL/SCLK
pin. To select the Asynchronous
Serial Interface, connect
ISCL/SCLK to VSS. For SPI
interface, SCLK must idle high.
ABSOLUTE MODE PACKAGE FORMAT
Byte # 7
1
1
2
3
4
0
0
0
6
0
Mouse
Y9
X6
Y6
5
0
Absolute
Y8
X5
Y5
Bit Number
4
3
0
0
1 penup 1 penup
Y7
X*
X4
X3
Y4
Y3
2
0
1 penup
X9
X2
Y2
1
0
0
0
1 penup 1 penup
X8
X7
X1
X0
Y1
Y0
Bit Number
4
3
Ysign
Xsign
2
M
1
R
0
L
X4
Y4
B4
X2
Y2
Z2
X1
Y1
Z1
X0
Y0
Z0
RELATIVE MODE PACKAGE FORMAT
Data Packet Format for
ScreenCoderTM SPI/Serial
The ScreenCoderTM SPI/Serial has
two different types of mouse
packages. One type is for absolute
position data from the touch screen
sensor and one is for relative data
from the external PS/2 device.
For both the Relative and Absolute
mode package format, each
packet contains 4 bytes. The 7th
bit of each byte is used for
synchronization. The 7th bit for the
first byte is 1 and for the other
bytes is 0. The resolution for
absolute position is 10 bits
(approximately 1000 points in X
and Y directions.) The relative
mouse data format supports
operations with WheelMouse and
5-button mice.
Identification and Revision for
ScreenCoderTM SPI/Serial
The UR7HCTS2-S840 offers a
special identification and revision
package. This package uses the
absolute mode format, but will not
appear in the normal absolute
mode. For normal absolute mode,
the first byte will be 80 Hex or 9F
Hex. This special 4-byte package
is identified by the first byte, 81
Hex. This data package is sent
upon power-up.
Copyright Semtech 2000-2001
DOC7-TS2-S840-DS-102
Byte # 7
1
1
2
3
4
0
0
0
6
0
Mouse
X6
Y6
X*
5
1
Relative
X5
Y5
B5
X3
Y3
Z3
Note 2: The bits that are marked with X* are reserved for future use. Now the value given is
zero.
Note 3: The X / Y data from external mouse is 9 bits. In our report, we truncate it to 8 bits.
The reduction is based on the fact that X / Y increments are seldom beyond the range of
+127/-128. For mouse data that exceeds this range, the ScreenCoderTM SPI/Serial will give
+127/-128.V8-V0: Revision
Hex 40 (Current Revision here)
IDENTIFICATION AND REVISION REPORT PACKAGE FORMAT
Byte # 7
1
1
2
0
3
0
4
0
(See Note 4 below)
6
0
F4
P2
V6
Note 4:
C3-C0: Class ID
F4-F0: Family ID
P2-P0: Sub Product Family
V8-V0: Revision
7
Bit Number
4
3
0
0
V7
C3
P0
F3
V4
V3
5
0
V8
P1
V5
Hex
Hex
Hex
Hex
7
A
1
40
2
0
C2
F2
V2
UR7HC
TS2
S840
(Current Revision here)
www.semtech.com
1
0
C1
F1
V1
0
1
C0
F0
V0
ASYNCHRONOUS SERIAL INTERFACE (ASI) MODE
Baud rate:
The ScreenCoderTM SPI/Serial transmits data at 19200 Baud, using the recommended 4MHz oscillator.
Protocol:
In Serial mode, the ScreenCoderTM SPI/Serial supports transmission in one direction only (IC to Host). The IC starts
the transmission to the system when it has mouse/keyboard package pending. The data format is one start bit, 8
data bits, no parity and one stop bit.
1. The ScreenCoderTM SPI/Serial asserts _CTS low to indicate that a packet transfer will start.
2. The Host asserts _RTS low to indicate that it is ready to receive data.
_RTS low means that system can receive data (e.g. UART is operational).
3. The UR7HCTS2-S840 places data on TXD line when it detects the _RTS low.
4. When one package is successfully transmitted, the IC raises _CTS.
Notes on the Protocol:
To assure fast transmission, the system must assert _RTS low as soon as possible. If the system is ready to receive
the data, it doesn't have to raise _RTS between packages.
The UR7HCTS2-S840 checks _RTS after every byte transmission. If _RTS returns to high, it means that the
transmission was unsuccessful. The IC will raise _CTS to abort the transmission and the entire package will be retransmitted.
The maximum time of T1 is 10ms. If the system cannot assert _RTS low after 10ms of _CTS low, the IC will raise
_CTS to abort the transmission request. After that, the ScreenCoderTM SPI/Serial will try to start the transmission
again.
_CTS
_RTS
1st
Byte
TXD
Last
Byte
t1
Figure 1: Serial Transmission Timing
Copyright Semtech 2000-2001
DOC7-TS2-S840-DS-102
8
www.semtech.com
SERIAL PERIPHERAL INTERFACE (SPI) MODE
The Serial Peripheral Interface (SPI) is a synchronous bi-directional multi-slave protocol. In SPI mode, the
ScreenCoderTM SPI/Serial acts as a slave device. The IC only supports transmission and doesn't support receiving.
SPI data transfer can be performed at a maximum clock rate of 500 KHz. The SDATA pin outputs data every time
the transfer clock changes from high to low level.
Protocol:
1. The UR7HCTS2-S840 asserts _ATN low to indicate that a mouse packet is waiting for transfer.
2. The Host asserts _SS low to indicate that it is ready to receive data. _SS low means the system selected SPI
ScreenCoderTM SPI/Serial as its communication device.
3. On detecting _SS low, the IC enables the SPI interface and places data in the SPI data TX buffer. After a short
delay, the system supplies eight clocks to get the data from the IC. The minimum time t2 from _SS low to first SPI
clock is 50us.
4. When a byte is transferred successfully, the system has to wait a minimum of 50us to begin the clocks for next
byte transmission.
5. When the mouse package is transmitted, the system stops the SPI clock. If it needs to communicate with other
SPI devices, it has to wait for _ATN return to high. _ATN high means the SPI port of UR7HCTS2-S840 is now in high
Impedance State.
_ATN
_SS
SCLK
2nd
Byte
1st
Byte
SDATA
t1
t2
t3
Last
Byte
t4
Figure 2: SPI Transmission Timing: (_SS toggles for every package).
Notes on the Protocol:
To assure the fast transmission, system must assert _SS low as soon as possible, see Figure 2. If the system is
ready to get data, it doesn't have to raise _SS between packages, see Figure 3.
Copyright Semtech 2000-2001
DOC7-TS2-S840-DS-102
9
www.semtech.com
PROTOCOLS FOR THE UR7HCTS2-S840 IN SPI MODE (CON’T)
SPI Communication Timing Parameters
Symbol
t1
t2
Description
_ATN low to _SS low
_SS low to first clock
(_SS toggles for every package)
_ATN low to first clock
(_SS low)
Last clock of transmitted
byte to next byte’s first clock
Last byte TX finish to
_ATN to high
t2’
t3
t4
Min
50
Max
10
5000
Units
ms
us
50
5000
us
50
5000
us
30
us
t2
_ATN
_SS
SCLK
SDATA
2nd
Byte
1st
Byte
Last
Byte
t4
t3
Figure 3: SPI Packet Transmission Timing: (_SS low always).
Copyright Semtech 2000-2001
DOC7-TS2-S840-DS-102
10
www.semtech.com
C3
RN1
4.7K
GND
www.semtech.com
SXR
SYB
SYT
SXL
GND
GND
32
31
30
29
28
27
26
25
XL
YT
YB
XR
23
SYT
SXL
PWR_DOWN
SOUT
ISEL/SCLK
TXD
RSVD2
RB
S840 == SCI/SPI Out, 4.00 MHz, 8/4- wire, Model 0.
Connect Drive and Sense lines together for the 4-wire Sensor.
Y1 == 4.00 MHz Ceramic Resonator with Built-in Load Capacitors.
Crystals can NOT be used.
NOTES:
10nF
+/-10% X7R
C6
10nF
+/-10% X7R
C5
10nF
+/-10% X7R
C4
10nF
+/-10% X7R
PWR_ON
_CTS
TXD
_RTS
2
1
SENSE_XL
SENSE_YT
SENSE_YB
SENSE_XR
4
3
DRV_XL
DRV_YT
DRV_YB
DRV_XR
6
5
See Note s
GND
RIGHT BUTTON
8
7
24
LB
SYB
1
U1
EXT_POWER_SENSE
.1uF
C1
9
10
11
12
13
14
15
16
1
VDD
VDD
GND
GND
EXT_PS2_VDD
GND
C2
10uF
Y1
4.00MHz
U2
TC54VC4502ECB
GND
OSCIN
OSCOUT
VSS
XR1
YB1
YT1
XL1
RTS/SS
NOT_RESET
GND
ASI Interface
32-pin LQFP
UR7HCTS2-S840
XR2
22
XPWRS
3
CTS/ATN
4
VREF
5
SXR
2
YB2
21
YT2
20
XL2
19
RVSD1
RESET
6
17
XCLK
18
XDAT
VSS2
7
VDD
8
LEFT BUTTON
2
11
3
EXT_M_CLOCK
EXT_M_DATA
47pF
C8
GND
47pF
C7
( C ) 2 0 0 0 U S A R S y s t e ms, A Semtech Company
S c r e e n C o d e r I I U R 7 H CTS2-S840-FG SCI Interface
D o c ument Number UR7HCTS2S820 Rev 0.60 VM
Mounti ng
holes
1
3
4
2
5
MDIN6_SH
JP1
L1
12uH
6
EXT_PS2_VDD
7
SW2
SHIELD
Copyright Semtech 2000-2001
DOC7-TS2-S840-DS-102
8
SW1
SUGGESTED INTERFACING FOR THE SCREENCODERTM SPI/SERIAL UR7HCTS2-S840-FG IN SERIAL MODE
C3
RN1
4.7K
www.semtech.com
SXR
SYB
SYT
SXL
GND
32
31
30
29
28
27
26
25
XL
YT
YB
XR
S840 == SCI/SPI Out, 4.00 MHz, 8/4- wire, Model 0.
Connect Drive and Sense lines together for the 4-wire Sensor.
Y1 == 4.00 MHz Ceramic Resonator with Built-in Load Capacitors.
Crystals can NOT be used.
NOTES:
GND
10nF
+/-10% X7R
C6
10nF
+/-10% X7R
C5
10nF
+/-10% X7R
C4
10nF
+/-10% X7R
PWR_ON
SOUT
SCLK
_ATN
_SS
2
1
SENSE_XL
SENSE_YT
SENSE_YB
SENSE_XR
4
3
DRV_XL
DRV_YT
DRV_YB
DRV_XR
6
5
See Note s
GND
RIGHT BUTTON
8
7
23
SYT
SXL
PWR_DOWN
SOUT
ISEL/SCLK
TXD
RSVD2
RB
24
LB
SYB
1
XR2
22
U1
UR7HCTS2_S840
32-pin LQFP
SPI Interface
XPWRS
3
CTS/ATN
C2
GND
EXT_PS2_VDD
1
GND
VDD
VDD
10uF
Y1
GND
4.00MHz
.1uF
C1
9
10
11
12
13
14
15
16
U2
TC54VC4502ECB
GND
OSCIN
OSCOUT
VSS
XR1
YB1
YT1
XL1
RTS/SS
NOT_RESET
GND
EXT_POWER_SENSE
4
VREF
5
SXR
2
YB2
21
YT2
20
XL2
19
RVSD1
RESET
6
17
XCLK
18
XDAT
VSS2
7
VDD
8
LEFT BUTTON
2
12
3
EXT_M_CLOCK
EXT_M_DATA
3
1
4
2
47pF
C8
GND
47pF
C7
( C ) 2 0 0 0 U S A R S y s t ems, A Semtech Company
S c r e e n C o d e r I I U R 7 H C T S 2-S840-FG SPI Interface
D o c u ment Number UR7HCTS2S840.sch Rev 0.60
Mounti ng
holes
5
MDIN6_SH
JP1
L1
12uH
6
EXT_PS2_VDD
7
SW2
SHIELD
Copyright Semtech 2000-2001
DOC7-TS2-S840-DS-102
8
SW1
SUGGESTED INTERFACING FOR THE SCREENCODERTM SPI/SERIAL UR7HCTS2-S840-FG IN SPI MODE
MECHANICAL INFORMATION FOR THE FG PACKAGE
HD
D
32
e
25
F
24
8
17
E
HE
1
y
b
L1
A2
9
A1
c
Symbol
L
Detail F
A
b2
ME
e
MD
I2
A
A1
A2
b
c
D
E
e
HD
HE
L
L1
y
b2
I2
MD
ME
16
Dimension in Millimeters
Min
Nom
Max
–
–
1.7
0.1
0.2
0
1.4
–
–
0.3
0.35
0.45
0.105
0.125
0.175
6.9
7.0
7.1
6.9
7.0
7.1
0.8
–
–
8.8
9.0
9.2
8.8
9.0
9.2
0.3
0.5
0.7
1.0
–
–
0.1
–
–
0ϒ
10ϒ
–
0.5
–
–
–
–
1.0
–
–
7.4
–
–
7.4
Recommended PCB Footprint
Copyright Semtech 2000-2001
DOC7-TS2-S840-DS-102
13
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-S840
Storage Temperature Range
Symbol
Vdd
Vin
I
Value
-0.3 to 7.0
Vss -0.3 to Vdd +0.3
20
Unit
V
V
mA
Ta
T low to T high
-20 to +85
-40 to +125
°C
°C
°C
Tstg
DC Electrical Characteristics, Temperature range=T low to T high unless otherwise noted)
Characteristic
Symbol
Min
Typ
Max
Supply Voltage
3.0
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
0.2xVdd
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=T low to T high unless otherwise noted)
Characteristic
Symbol
Min
Typ
Max
Unit
Frequency of Operation
fosc
MHz
Ceramic Resonator Option
4.0
External Clock Option
4.0
Copyright Semtech 2000-2001
DOC7-TS2-S840-DS-102
14
www.semtech.com
SCREENCODERTM SPI/SERIAL BILL OF MATERIALS FOR PAGE 12 SCHEMATIC
UR7HCTS2-S840-FG BOM
Description
Quantity
Bare PCB:
PCB1
1
Capacitor:
C1, C4
2
C2, C3, C7, C8
4
C5, C10
2
C6, C9
2
C11-C14
4
Custom IC:
U1
1
U4
1
ICs:
U2
1
U3, U5
2
Inductor:
L1
1
Push Button:
Left, Right
2
Resistor
Network:
RN1
1
Resistor:
R1
1
R2
1
R3
1
Resonator:
Y1, Y2
2
Manufacturer
Part#
Description
USAR
PCB7-TS2-S840-060
SPI/Serial Touchscreen PCB
Generic
Generic
Generic
Generic
Generic
Any
Any
Any
Any
Any
47pF, 10%, Ceramic, X7R or NPO, SMT Size 1206
1uF, 16V, Tantalum Cap, SMT, Size 1206
10uF, 20V, Tantalum Cap, SMT, Size C
.1uF Ceramic Chip Cap, Z5U, SMT, 1206
.01uF, Ceramic Chip Cap, SMT, NPO, or X7R, 1206
USAR
USAR
UR7HCTS2-S840-FG
UR6HCASI-S40T-FB
SPI/Serial ScreenCoderTM Controller
SPI to Serial Test Chip
Analog Devices
TelCom
ADM232LJR
TC54VC4302EMB
232 Driver_Receiver Chip in SMT
4.3V, Volt Detector, THD, TO-83
Generic
Any
12uH Inductor, SMT, 1210 (3225)
Generic
Any
Switch, 8mm, light touch, THD
CTS
744-083-472J
4.7K, 4 Resistor, 8 terminals, SMT
Generic
Generic
Generic
Any
Any
Any
4.7K Resistor, 5% Thick Film, SMT, 1206
10K Resistor, 5% Thick Film, SMT, 1206
1M Resistor, 5% Thick Film, SMT, 1206
AVX
PBRC-4.00BR
4.00MHz Resonator, SMT
Note: Auxiliary components are not shown.
Revised 08/24/00
Copyright Semtech 2000-2001
DOC7-TS2-S840-DS-102
15
www.semtech.com
For sales information
and product literature,
contact:
HID & System Mgmt Division
Semtech Corporation
568 Broadway
New York, NY 10012
[email protected]
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
+886-2-2748-3380 Telephone
+886-2-2748-3390 Telefax
Semtech Japan Sales Office
+81-45-948-5925 Telephone
+81-45-948-5930 Telefax
Semtech Korea Sales Sales
+82-2-527-4377 Telephone
+82-2-527-4376 Telefax
Northern European Sales Office
+44 (0)2380-769008 Telephone
+44 (0)2380-768612 Telefax
Southern European Sales Office
+33 (0)1 69-28-22-00 Telephone
+33 (0)1 69-28-12-98 Telefax
Central European Sales Office
+49 (0)8161 140 123 Telephone
+49 (0)8161 140 124 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.
Copyright Semtech 2000-2001
DOC7-TS2-S840-DS-102
16
www.semtech.com