AD7147A Analog Devices, AD7147A Datasheet - Page 15

• Manufacturer Part Number: AD7147A
• Manufacturer: Analog Devices

Specifications of AD7147A

• Resolution (bits): 16bit
• # Chan: 13
• Sample Rate: 111SPS
• Interface: I²C/Ser 2-Wire,Ser,SPI
• Analog Input Type: Capacitive
• Ain Range: ± 8 pF (Delta C)
• Adc Architecture: Sigma-Delta
• Pkg Type: CSP

A button sensor generally requires one sequencer stage; this is
shown in Figure 25 as B1. However, it is possible to configure
two button sensors to operate differentially for one conversion
stage. Only one button can be activated at a time; pressing both
buttons simultaneously results in neither button being activated.
The configuration with two button sensors operating differen-
tially requires one conversion stage and is shown in Figure 25,
with B2 and B3 representing the differentially configured button
sensors.
SCROLL
WHEEL
CIN10
CIN11
CIN12
CIN0
CIN1
CIN2
CIN3
CIN4
CIN5
CIN6
CIN7
CIN8
CIN9
Figure 25. Sequencer Setup for Sensors
Figure 24. CDC Conversion Stages
STAGE0
STAGE1
Rev. B | Page 15 of 68
STAGE2
SEQUENCER
AD7147A
STAGE3
STAGE4
STAGE0
STAGE1
STAGE2
STAGE3
STAGE4
STAGE5
STAGE6
STAGE7
STAGE5
+
–
+
–
+
–
+
–
+
–
+
–
+
–
+
– CDC
STAGE6
16-BIT
CDC
CDC
CDC
CDC
CDC
CDC
CDC
STAGE7
ADC
Σ-Δ
STAGE8
STAGE9
STAGE10
STAGE11
A wheel sensor requires eight stages, whereas a slider requires
two stages. The result from each stage is used by the host soft-
ware to determine the user’s position on the slider or wheel. The
algorithms that perform this process are available from Analog
Devices and are free of charge but require signing a software
license.
SLIDER
BUTTONS
B1
B2
B3
SEQUENCER
AD7147A
SEQUENCER
STAGE8
STAGE9
AD7147A
STAGE10
STAGE11
+
–
+
–
CDC
CDC
+
–
+
–
CDC
CDC
AD7147A