AD7142 Analog Devices, AD7142 Datasheet - Page 10

• Manufacturer Part Number: AD7142
• Description: Programmable Controller for Capacitance Touch Sensors
• Manufacturer: Analog Devices

Specifications of AD7142

• Resolution (bits): 16bit
• # Chan: 14
• Sample Rate: 250kSPS
• Interface: I²C/Ser 2-Wire,Ser,SPI
• Analog Input Type: Diff-Uni
• Ain Range: ± 2 pF (Delta C)
• Adc Architecture: Sigma-Delta
• Pkg Type: CSP

AD7142
TYPICAL PERFORMANCE CHARACTERISTICS
1000
120
100
980
960
940
920
900
880
860
840
820
Decimation Rate = 256 (V
Decimation Rate = 128 (V
80
60
40
20
180
160
140
120
100
Figure 10. Low Power Supply Current vs. Supply Voltage
Figure 9. Low Power Supply Current vs. Supply Voltage,
2.7
80
60
40
2.7
2.7
DEVICE 2
LP_CONV_DELAY = 600ms
Figure 8. Supply Current vs. Supply Voltage
2.8
2.8
2.8
LP_CONV_DELAY = 200ms
LP_CONV_DELAY = 400ms
LP_CONV_DELAY = 600ms
LP_CONV_DELAY = 800ms
(V
CC
2.9
2.9
= AV
2.9
DEVICE 3
3.0
CC
3.0
3.0
+ DV
LP_CONV_DELAY = 200ms
CC
CC
LP_CONV_DELAY = 800ms
3.1
3.10
= AV
= AV
CC
V
V
3.1
CC
, I
CC
V
CC
LP_CONV_DELAY = 400ms
CC
3.2
(V)
CC
CC
(V)
= AI
3.2
DEVICE 1
(V)
+ DV
+ DV
3.2
CC
3.3
+ DI
CC
CC
3.3
, I
, I
3.3
CC
CC
CC
3.4
= AI
= AI
)
3.4
3.4
CC
CC
3.5
+ DI
+ DI
3.5
3.5
CC
CC
3.6
)
)
3.6
3.6
Rev. A | Page 10 of 72
Figure 12. Supply Current vs. Capacitive Load on SRC (I
16015
16010
16005
16000
15995
15990
15985
15980
2.45
2.30
2.15
2.00
1.85
1.70
1.55
1.40
1.10
1.05
1.00
0.95
0.90
0.85
0.80
Figure 11. Shutdown Supply Current vs. Supply Voltage
2.7
0
0
Figure 13. Output Code vs. Capacitive Load on SRC
DEVICE 3
2.8
50
50
DEVICE 1
(V
DEVICE 1
CC
100
100
2.9
CAPACITANCE LOAD ON SOURCE (pF)
CAPACITANCE LOAD ON SOURCE (pF)
= AV
DEVICE 3
150
150
3.0
CC
+ DV
200
200
3.1
CC
V
, I
CC
DEVICE 2
250
250
CC
3.2
(V)
= AI
300
300
DEVICE 2
CC
3.3
DEVICE 2
+ DI
DEVICE 3
350
350
CC
3.4
)
400
400
DEVICE 1
CC
3.5
= AI
450
450
CC
3.6
+ DI
500
500
CC
)