EVAL-AD7747EBZ Analog Devices Inc, EVAL-AD7747EBZ Datasheet - Page 4

• Manufacturer Part Number: EVAL-AD7747EBZ
• Description: 24-Bit Capacitance-to-Digital Converter Eval. Board
• Manufacturer: Analog Devices Inc

Specifications of EVAL-AD7747EBZ

• Silicon Manufacturer: Analog Devices
• Application Sub Type: Capacitance-to-Digital Converter
• Kit Application Type: Data Converter
• Silicon Core Number: AD7747
• Sensor Type: Touch, Capacitive
• Interface: I²C
• Voltage - Supply: 2.7 V ~ 5.25 V
• Embedded: No
• Utilized Ic / Part: AD7747
• Kit Contents: Board
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Sensitivity: -
• Sensing Range: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

AD7747
Parameter
INTERNAL VOLTAGE REFERENCE
EXTERNAL VOLTAGE REFERENCE INPUT
SERIAL INTERFACE LOGIC INPUTS (SCL, SDA)
OPEN-DRAIN OUTPUT (SDA)
LOGIC OUTPUT ( RDY )
POWER REQUIREMENTS
1
2
3
4
5
6
7
8
9
Capacitance units: 1 pF = 10
Specification is not production tested, but is supported by characterization data at initial product release.
Factory calibrated. The absolute error includes factory gain calibration error, integral nonlinearity error, and offset error after system offset calibration, all at 25°C.
At different temperatures, compensation for gain drift over temperature is required.
The capacitive input offset can be eliminated using a system offset calibration. The accuracy of the system offset calibration is limited by the offset calibration register
LSB size (32 aF) or by converter + system p-p noise during the system capacitive offset calibration, whichever is greater. To minimize the effect of the converter +
system noise, longer conversion times should be used for system capacitive offset calibration. The system capacitance offset calibration range is ±1 pF; the larger
offset can be removed using CAPDACs.
Specification is not production tested, but guaranteed by design.
The gain error is factory calibrated at 25°C. At different temperatures, compensation for gain drift over temperature is required.
The VTCHOP bit in the VT SETUP register must be set to 1 for the specified temperature sensor and voltage input performance.
Using an external temperature sensing diode 2N3906, with nonideality factor n
Full-scale error applies to both positive and negative full scale.
Normal Mode Rejection
Common-Mode Rejection
Voltage
Drift vs. Temperature
Differential REFIN Voltage
Absolute REFIN Voltage
Average REFIN Input Current
Average REFIN Input Current Drift
Common-Mode Rejection
V
V
Hysteresis
Input Leakage Current (SCL)
V
I
V
V
V
V
V
I
I
OH
DD
DD
IH
IL
OL
OL
OH
OL
OH
DD
Input Low Voltage
Output High Leakage Current
Current
Current Power-Down Mode
Input High Voltage
-to-GND Voltage
Output Low Voltage
Output Low Voltage
Output Low Voltage
Output High Voltage
Output High Voltage
−12
2
5
F; 1 fF = 10
2
2
−15
F; 1 aF = 10
Min
1.169
0.1
GND − 0.03
2.1
4.0
V
4.75
2.7
DD
−18
− 0.6
F. Full scale (FS) = 8.192 pF; full-scale range (FSR) = ±8.192 pF.
Typ
75
50
95
1.17
5
2.5
400
±50
80
150
±0.1
0.1
750
700
0.5
Rev. 0 | Page 4 of 28
f
= 1.008, connected as in Figure 37, with total serial resistance <100 Ω.
Max
1.171
V
V
0.8
±1
0.4
1
0.4
0.4
5.25
3.6
850
2
DD
DD
+ 0.03
Unit
dB
dB
dB
V
ppm/°C
V
V
nA/V
pA/V/°C
dB
V
V
mV
μA
V
μA
V
V
V
V
V
V
μA
μA
μA
μA
Test Conditions/Comments
50 Hz ± 1%, conversion time = 122.1 ms
60 Hz ± 1%, conversion time = 122.1 ms
V
T
I
V
I
I
I
I
V
V
Digital inputs equal to V
V
V
Digital inputs equal to V
SINK
SINK
SOURCE
SINK
SOURCE
A
IN
OUT
DD
DD
DD
DD
= 25°C
= 1 V
= 5 V, nominal
= 3.3 V, nominal
= 5 V
= 3.3 V
= −6.0 mA
= 1.6 mA, V
= 100 μA, V
= V
= 200 μA, V
= 100 μA, V
DD
DD
DD
DD
DD
= 5 V
= 3 V
= 5 V
= 3 V
DD
DD
or GND
or GND