TSC2200 Datasheet, PDF (8/40 Pages) Burr-Brown (TI) – PDA ANALOG INTERFACE CIRCUIT

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.
Touch
Screen
Keypad
1µF
to
+
10µF
(Optional)
Voltage
Regulator
+2.7V to +3.3V
1µF
to
+
10µF
(Optional)
0.1µF
0.1µF
TSC2200IPW
1 +V_DD
2 X+
3 Y+
4 X–
5 Y–
6 GND
7 V_BAT1
8 V_BAT2
9 V_REF
10 KBIRQ
11 R1
12 R2
13 R3
14 R4
AUX1 28
AUX2 27
ARNG 26
A_OUT 25
PENIRQ 24
MISO 23
DAV 22
MOSI 21
SS 20
SCLK 19
C4 18
C3 17
C2 16
C1 15
LCD Contrast
Auxiliary Input
Auxiliary Input
Pen Interrupt Request
Serial Data Out
Data Available
Serial Data In
Slave Select
Serial Clock
RRNG
Main
Battery
Secondary
Battery
FIGURE 1. Typical Circuit Configuration.
8
www.ti.com
Keyboard Interrupt Request
TSC2200
SBAS191F