AD7142 Analog Devices, AD7142 Datasheet - Page 4

• 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
SPECIFICATIONS
AV
Table 1.
Parameter
CAPACITANCE-TO-DIGITAL CONVERTER
EXCITATION SOURCE
LOGIC INPUTS (SDI, SCLK, CS , SDA, GPI TEST)
OPEN-DRAIN OUTPUTS (SCLK, SDA, INT)
LOGIC OUTPUTS (SDO, GPO)
POWER
1
C
IN
Update Rate
Resolution
CIN Input Range
No Missing Codes
CIN Input Leakage
Total Unadjusted Error
Output Noise (Peak-to-Peak)
Output Noise (RMS)
Parasitic Capacitance
C
C
Low Power Mode Delay Accuracy
Frequency
Output Voltage
Short-Circuit Source Current
Short-Circuit Sink Current
Maximum Output Load
C
C
V
V
I
I
Hysteresis
V
I
V
V
SDO Floating State Leakage Current
GPO Floating State Leakage Current
AV
V
I
IH
IL
OH
CC
CC
and C
BULK
BULK
SHIELD
SHIELD
IH
IL
OL
OL
OH
DRIVE
Input High Voltage
Input Low Voltage
, DV
CC
Input High Voltage
Input Low Voltage
Output High Leakage Current
Output Low Voltage
Output Low Voltage
Output High Voltage
, DV
Offset Range
Offset Resolution
BULK
Output Drive
Bias Level
CC
CC
are defined in Figure 2.
= 2.6 V to 3.6 V, T
1
1
A
= −40
o
C to +85°C, unless otherwise noted.
Min
35.45
16
240
0.7 × V
−1
V
−5
2.6
1.65
DRIVE
− 0.6
DRIVE
Typ
36.86
16
±2
25
7
3
0.8
0.5
±20
156.25
250
20
50
250
10
AV
150
0.1
3.3
0.9
16
2.25
CC
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Max
38.4
±20
40
4
260
AV
0.4
1
0.4
±1
0.4
±1
2
3.6
3.6
1
20
33
4.5
18
CC
Unit
ms
Bit
pF
Bit
nA
%
Codes
Codes
Codes
Codes
pF
pF
fF
%
kHz
V
mA
mA
pF
μA
V
V
V
μA
μA
mV
V
μA
V
V
μA
μA
V
V
mA
μA
μA
μA
μA
Decimation rate = 128
Decimation rate = 128
Test Conditions/Comments
12 conversion stages in sequencer, decimation rate = 256
Guaranteed by design, but not production tested
Decimation rate = 256
Decimation rate = 256
Parasitic capacitance to ground, per CIN input
guaranteed by characterization
% of 200 ms, 400 ms, 600 ms, or 800 ms
Capacitance load on source to ground
V
V
I
V
I
I
Pin three-state, leakage measured to GND and DV
Pin three-state, leakage measured to GND and DV
Serial interface operating voltage
In full power mode
Low power mode, converter idle, T
Low power mode, converter idle
Full shutdown, T
Full shutdown
SINK
SINK
SOURCE
IN
IN
OUT
= V
= DGND
= −1 mA
= 1 mA, V
= V
= 1 mA, V
DRIVE
DRIVE
DRIVE
DRIVE
A
= 25°C
= 1.65 V to 3.6 V
= 1.65 V to 3.6 V
A
= 25°C
CC
CC