Datasheet

TSC2003
11
SBAS162G
www.ti.com
INTERNAL REFERENCE
The TSC2003 has an internal 2.5V voltage reference that
can be turned ON or OFF with the power-down control bits,
PD0 and PD1 (see Table II and Figure 3). The internal
reference is powered down when power is first applied to the
device.
The internal reference voltage is only used in the
single-ended reference mode for battery monitoring, tem-
perature measurement, and for measuring the auxiliary in-
put. Optimal touch screen performance is achieved when
using a ratiometric conversion; thus, all touch screen mea-
surements are done automatically in the differential mode.
Buffer
Band
Gap
Reference
Power Down
To
CDAC
Optional
V
REF
FIGURE 3. Simplified Diagram of the Internal Reference.
FIGURE 2. Simplified Diagram of the Analog Input.
Converter
–REF
+REF
+IN
–IN
V
BAT1
IN1
Battery
On
IN2
GND
C2-C0
(Shown 101
B
)
2.5V
Reference
Ref ON/OFF
C3
(Shown HIGH)
X+
X–
+V
DD
TEMP1
PENIRQ
Y+
Y–
V
REF
TEMP0
7.5kΩ
V
BAT2
7.5kΩ
2.5kΩ
Battery
On
2.5kΩ