Datasheet
8
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TSC2200
SBAS191F
FIGURE 1. Typical Circuit Configuration.
OVERVIEW
The TSC2200 is an analog interface circuit for human inter-
face devices. A register-based architecture eases integration
with microprocessor-based systems through a standard SPI
bus. All peripheral functions are controlled through the reg-
isters and onboard state machines.
The TSC2200 consists of the following blocks (refer to the
block diagram on the front page):
• Touch Screen Interface
• Keypad Interface
• Battery Monitors
• Auxiliary Inputs
• Temperature Monitor
• Current Output D/A Converter
Communication to the TSC2200 is via a standard SPI serial
interface. This interface requires that the Slave Select signal be
driven LOW to communicate with the TSC2200. Data is then
shifted into or out of the TSC2200 under control of the host
microprocessor, which also provides the serial data clock.
Control of the TSC2200 and its functions is accomplished by
writing to different registers in the TSC2200. A simple com-
mand protocol is used to address the 16-bit registers. Reg-
isters control the operation of the A/D converter, D/A con-
verter, and keypad scanner.
The result of measurements made will be placed in the
TSC2200’s memory map and may be read by the host at any
time. Three signals are available from the TSC2200 to indicate
that data is available for the host to read. The
DAV
output
indicates that an A/D conversion has completed and that data
is available. The
KBIRQ
output indicates that a key on the
keypad has been pressed. The
PENIRQ
output indicates that
a touch has been detected on the touch screen. A typical
application of the TSC2200 is shown in Figure 1.
+
Auxiliary Input
Auxiliary Input
Pen Interrupt Request
Serial Data Out
Data Available
Serial Data In
Slave Select
Serial Clock
1µF
to
10µF
(Optional)
+2.7V to +3.3V
Touch
Screen
0.1µF
+V
DD
X+
Y+
X–
Y–
GND
V
BAT1
V
BAT2
V
REF
KBIRQ
R1
R2
R3
R4
AUX1
AUX2
ARNG
A
OUT
PENIRQ
MISO
DAV
MOSI
SS
SCLK
C4
C3
C2
C1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
TSC2200IPW
+
1µF
to
10µF
(Optional)
0.1µF
Main
Battery
Secondary
Battery
Keypad
Keyboard Interrupt Request
LCD Contrast
Voltage
Regulator
RRNG