AR1000_16 Datasheet, PDF (12/61 Pages) Microchip Technology – AR1000 Series Resistive Touch Screen Controller

AR1000 SERIES RESISTIVE TOUCH SCREEN CONTROLLER
3.5 8-Wire Touch Sensor Interface
Sensor tail pinouts can vary by manufacturer and part
number. Ensure both sensor tail pins for one sensor
axis (layer) are connected to the controller’s X-/X+ pins
and the tail pins for the other sensor axis (layer) are
connected to the controller’s Y-/Y+ pins.
The controller’s X-/X+ and Y-/Y+ pin pairs do not need
to connect to a specific sensor axis. The orientation of
controller pins X- and X+ to the two sides of a given
sensor axis is not important. Likewise, the orientation of
controller pins Y- and Y+ to the two sides of the other
sensor axis is not important.
The 8-wire sensor differs from a 4-wire sensor in that
each edge of an 8-wire sensor has a secondary
connection brought to the sensor’s tail. These
secondary connections are referred to as “sense” lines.
The controller pins associated with the sense line for an
8-wire sensor contain an ‘S’ prefix in their respective
names. For example, the SY- pin is the sense line
connection associated with the main Y- pin connection.
Consult with the sensor manufacturer’s specification to
determine which member of each edge connected pair
is the special 8-wire “sense” connection. Incorrectly
connecting the sense and excite lines to the controller
will adversely affect performance.
The controller requires that the main and “sense” tail
pin pairs for sensor edges be connected to controller
pin pairs as follows:
• Y- and SY-
• Y+ and SY+
• X- and 5WSX-
• X+ and SX+
Connections to a 8-wire touch sensor are shown in
Figure 3-4 below.
FIGURE 3-4:
8-WIRE TOUCH SENSOR INTERFACE
See Section 3.8 “ESD Considerations” and
Section 3.9 “Noise Considerations” for important
information regarding the capacitance of the controller
schematic hardware.
DS40001393C-page 12
 2009-2016 Microchip Technology Inc.