Production Data
WM9712L
TOUCHPANEL AND AUXILIARY ADC
Test Conditions
DBVDD=3.3V, DCVDD = 3.3V, AVDD = TPVDD = 3.3V, T
A
= +25
o
C, MCLK = 24.576 MHz, unless otherwise stated.
PARAMETER
Input Voltage
Input leakage current
ADC Resolution
Differential Non-Linearity Error
Integral Non-Linearity Error
Offset Error
Gain Error
Power Supply Rejection
Throughput Rate
Settling Time (programmable)
Conversion Time
PSRR
DEL = 1111
(zero settling time)
MCLK = 24.576MHz
Note: touch pressure
measurements require
two conversions
R
PU
I
P
RPU = 000001
PIL = 1
PIL = 0
BMON/AUX3 (pin 31 only)
Input Range
Scaling
Input Resistance (Note 1)
during measurement
average over time
AVDD = 3.3V
AVDD = 1.8V
AGND
AGND
-3%
1/3
30
30 /
duty cycle
5
3.3
+3%
kΩ
V
V
55
0
20.8
50
48
6
DNL
INL
AUX pin not selected as
AUX ADC input
SYMBOL
TEST CONDITIONS
MIN
AGND
<10
12
±0.25
±1
±2
±4
±6
TYP
MAX
AVDD
UNIT
V
nA
bits
LSB
LSB
LSB
LSB
dB
kHz
ms
µs
Input Pins X+, X-, Y+, Y-, WIPER/AUX4, COMP1/AUX1, COMP2/AUX2 and BMON/AUX3
Switch matrix resistance
Programmable Pull-up resistor
Pen down detector threshold
Pressure measurement current
12
63
VDD/2
400
200
70
Ω
kΩ
V
µA
Note:
1. Current only flows into pin 31 during a measurement. At all other times, BMON/AUX3 is effectively an open circuit.
COMPARATORS
Test Conditions
AVDD = 3.3V, T
A
= +25
o
C, unless otherwise stated.
PARAMETER
Input Voltage
Input leakage current
Comparator Input Offset
(COMP1, COMP2 only)
COMP2 delay (COMP2 only)
24.576MHz crystal
pin not selected as AUX
ADC input
-50
0
SYMBOL
TEST CONDITIONS
MIN
AGND
<10
+50
10.9
TYP
MAX
AVDD
UNIT
V
nA
mV
s
COMP1/AUX1 and COMP2/AUX2 (pins 29, 30)
w
PD Rev 4.0 December 2003
9