Datasheet

AD7879/AD7889
Rev. C | Page 8 of 40
07667-007
PIN 1
INDICATOR
1Y+
2NC
3NC
4X–
11 NC
12
10 NC
9 DOUT
5
Y–
6
DIN
7
GND
8
SCL
15
V
CC
/REF
16
X+
14
13
AUX/VBAT/GPIO
AD7879
TOP VIEW
(Not to Scale)
PENIRQ/INT/DAV
CS
NOTES
1. NC = NO CONNECT
2. THE EXPOSED PAD IS NOT CONNECTED INTERNALLY.
FOR INCREASED RELIABILITY OF THE SOLDER JOINTS
AND MAXIMUM THERMAL CAPABILITY, IT IS RECOMMENDED
THAT TH
E PAD BE SOLDERED TO THE GROUND PLANE.
Figure 7. AD7879 LFCSP Pin Configuration
07667-008
PIN 1
INDICATOR
1Y+
2NC
3NC
4X–
11 NC
12
10 NC
9 SDA
5
Y–
6
ADD1
7
GND
8
SCL
15
V
CC
/REF
16
X+
14
13
AUX/VBAT/GPIO
AD7879-1
TOP VIEW
(Not to Scale)
PENIRQ/INT/DAV
ADD0
NOTES
1. NC = NO CONNECT
2. THE EXPOSED PAD IS NOT CONNECTED INTERNALLY.
FOR INCREASED RELIABILITY OF THE SOLDER JOINTS
AND MAXIMUM THERMAL CAPABILITY, IT IS RECOMMENDED
THAT THE PAD BE SOLDERED TO THE GROUND PLANE.
Figure 8. AD7879-1 LFCSP Pin Configuration
Table 7. Pin Function Descriptions, LFCSP
Pin No.
Mnemonic Description
AD7879 AD7879-1
1 1 Y+ Touch Screen Input Channel.
2, 3, 10, 11 2, 3, 10, 11 NC No Connect.
4 4 X− Touch Screen Input Channel.
5 5 Y− Touch Screen Input Channel.
6 N/A DIN SPI Serial Data Input to the AD7879.
N/A 6 ADD1
I
2
C Address Bit 1 for the AD7879-1. This pin can be tied high or low to determine an address
for the AD7879-1 (see Table 25).
7 7 GND
Ground. Ground reference point for all circuitry on the AD7879. All analog input signals and
any external reference signal should be referred to this voltage.
8 8 SCL Serial Interface Clock Input.
9 N/A DOUT SPI Serial Data Output for the AD7879.
N/A 9 SDA I
2
C Serial Data Input and Output for the AD7879-1.
12 12
PENIRQ/INT/DAV Interrupt Output. This pin is asserted when the screen is touched (PENIRQ), when a measure-
ment exceeds the preprogrammed limits (INT
), or when new data is available in the registers
(DAV
). Active low, internal 50 kΩ pull-up resistor.
13 13 AUX/VBAT/GPIO
This pin can be programmed as an auxiliary input to the ADC (AUX), as a battery measure-
ment input to the ADC ( VBAT ), or as a general-purpose digital input/output (GPIO).
14 N/A
CS
Chip Select for the SPI Serial Interface on the AD7879. Active low.
N/A 14 ADD0
I
2
C Address Bit 0 for the AD7879-1. This pin can be tied high or low to determine an address
for the AD7879-1 (see Table 25).
15 15 V
CC
/REF Power Supply Input and ADC Reference.
16 16 X+ Touch Screen Input Channel.
EP
Exposed Pad. The exposed pad is not connected internally. For increased reliability of the
solder joints and maximum thermal capability, it is recommended that the pad be soldered
to the ground plane.