TSC2301_15 Datasheet, PDF (20/94 Pages) Texas Instruments – PROGRAMMABLE TOUCH SCREEN CONTROLLER

TSC2301
SLAS371D – SEPTEMBER 2002 – REVISED AUGUST 2004
www.ti.com
The ADC is controlled by an ADC control register. Several modes of operation are possible, depending upon the
bits set in the control register. Channel selection, scan operation, averaging, resolution, and conversion rate may
all be programmed through this register. These modes are outlined in the sections below for each type of analog
input. The results of conversions made are stored in the appropriate result register.
PENIRQ
+V_CC
TEMP1 TEMP0
V_REF
X+
X–
Ref ON/OFF
Y+
+IN ^+REF
Y–
Converter
1.25/2.5 V
–IN _–REF
Reference
V_BAT1
V_BAT2
7.5 kΩ
5.0 kΩ _{5.0 kΩ}
2.5 kΩ
Battery
on
Battery
on
IN1
IN2
GND
Figure 47. Simplified Diagram of the Touch Screen Analog Input Section
Data Format
The TSC2301 output data is in straight binary format as shown in Figure 48. This figure shows the ideal output
code for the given input voltage and does not include the effects of offset, gain, or noise.
11...111
11...110
11...101
FS = Full - Scale Voltage = V_REF
1 LSB = V_REF /4096
1 LSB
00...010
00...001
00...000
0V
FS - 1 LSB
Input Voltage - A
Figure 48. Ideal Input Voltages and Output Codes
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