MAX1233_05 Datasheet, PDF (14/45 Pages) Maxim Integrated Products – ±15kV ESD-Protected Touch-Screen Controllers Include DAC and Keypad Controller

±15kV ESD-Protected Touch-Screen
Controllers Include DAC and Keypad Controller
TEMP2
TEMP1
+AVDD
VREF
MAX1233
MAX1234
X+
X-
REF ON/OFF
Y+
+REF
+IN
Y-
CONVERTER
-IN
2.5V/1.0V
-REF
REFERENCE
VBAT1
VBAT2
7.5kΩ
7.5kΩ
AUX1
AUX2
GND
2.5kΩ
BATTERY
ON
2.5kΩ
BATTERY
ON
Figure 3. Simplified Diagram of Analog Input Section
Analog Input Protection
Internal protection diodes that clamp the analog input
to AV_DD and GND allow the analog input pins to swing
from GND - 0.3V to AV_DD + 0.3V without damage.
Analog inputs must not exceed AV_DD by more than
50mV or be lower than GND by more than 50mV for
accurate conversions. If an off-channel analog input
voltage exceeds the supplies, limit the input current to
50mA. All analog inputs are also fully ESD protected
to ±8kV, using the Contact-Discharge method and
±15kV using the Air-Gap method specified in IEC-
1000-4-2.
Reference for ADC
Internal Reference
The MAX1233/MAX1234 offer an internal voltage refer-
ence for the ADC that can be set to +1.0V or +2.5V. The
MAX1233/MAX1234 typically use the internal reference
for battery monitoring, temperature measurement, and for
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