WM9712L Datasheet, PDF (9/77 Pages) Wolfson Microelectronics plc – AC97 Audio and Touchpanel CODEC

Production Data
WM9712L
TOUCHPANEL AND AUXILIARY ADC
Test Conditions
DBVDD=3.3V, DCVDD = 3.3V, AVDD = TPVDD = 3.3V, TA = +25^oC, MCLK = 24.576 MHz, unless otherwise stated.
PARAMETER
SYMBOL TEST CONDITIONS
MIN
TYP
MAX
Input Pins X+, X-, Y+, Y-, WIPER/AUX4, COMP1/AUX1, COMP2/AUX2 and BMON/AUX3
Input Voltage
AGND
AVDD
Input leakage current
AUX pin not selected as
<10
AUX ADC input
ADC Resolution
12
Differential Non-Linearity Error DNL
±0.25
±1
Integral Non-Linearity Error
INL
±2
Offset Error
±4
Gain Error
±6
Power Supply Rejection
PSRR
50
Throughput Rate
DEL = 1111
48
(zero settling time)
Settling Time (programmable)
MCLK = 24.576MHz
0
6
Conversion Time
Note: touch pressure
20.8
measurements require
two conversions
Switch matrix resistance
12
Programmable Pull-up resistor RPU
RPU = 000001
55
63
70
Pen down detector threshold
VDD/2
Pressure measurement current IP
PIL = 1
400
PIL = 0
200
BMON/AUX3 (pin 31 only)
Input Range
AVDD = 3.3V
AGND
5
AVDD = 1.8V
AGND
3.3
Scaling
-3%
1/3
+3%
Input Resistance (Note 1)
during measurement
30
average over time
30 /
duty cycle
Note:
1. Current only flows into pin 31 during a measurement. At all other times, BMON/AUX3 is effectively an open circuit.
UNIT
V
nA
bits
LSB
LSB
LSB
LSB
dB
kHz
ms
µs
Ω
kΩ
V
µA
V
V
kΩ
COMPARATORS
Test Conditions
AVDD = 3.3V, TA = +25^oC, unless otherwise stated.
PARAMETER
SYMBOL TEST CONDITIONS
MIN
TYP
MAX
UNIT
COMP1/AUX1 and COMP2/AUX2 (pins 29, 30)
Input Voltage
AGND
AVDD
V
Input leakage current
pin not selected as AUX
<10
nA
ADC input
Comparator Input Offset
-50
+50
mV
(COMP1, COMP2 only)
COMP2 delay (COMP2 only)
24.576MHz crystal
0
10.9
s
w
PD Rev 4.5 August 2006
9