Datasheet
–3–REV. 0
AD7731
Parameter B Version
1
Units Conditions/Comments
Absolute/Common-Mode Voltage
13
AGND + 1.2 V V min
AV
DD
– 0.95 V V max
Reference Input
REF IN(+) – REF IN (–) Voltage +2.5 V nom HIREF Bit of Mode Register = 0
REF IN(+) – REF IN (–) Voltage +5 V nom HIREF Bit of Mode Register = 1
Reference DC Input Current 5.5 µA max HIREF Bit of Mode Register = 0
Reference DC Input Current 10 µA max HIREF Bit of Mode Register = 1
Absolute/Common-Mode Voltage
14
AGND – 30 mV V min
AV
DD
+ 30 mV V max
NO REF Trigger Voltage 0.3 V min NO REF Bit Active If VREF Below This Voltage
0.65 V max NO REF Bit Inactive If VREF Above This Voltage
LOGIC INPUTS
Input Current ±10 µA max
All Inputs Except SCLK and MCLK IN
V
INL
, Input Low Voltage 0.8 V max DV
DD
= +5 V
V
INL
, Input Low Voltage 0.4 V max DV
DD
= +3 V
V
INH
, Input High Voltage 2.0 V min
SCLK Only (Schmitt Triggered Input)
V
T+
1.4/3 V min/V max DV
DD
= +5 V
V
T+
0.95/2.5 V min/V max DV
DD
= +3 V
V
T–
0.8/1.4 V min/V max DV
DD
= +5 V
V
T–
0.4/1.1 V min/V max DV
DD
= +3 V
V
T+
– V
T–
0.4/0.85 V min/V max DV
DD
= +5 V
V
T+
– V
T–
0.4/0.8 V min/V max DV
DD
= +3 V
MCLK IN Only
V
INL
, Input Low Voltage 0.8 V max DV
DD
= +5 V
V
INL
, Input Low Voltage 0.4 V max DV
DD
= +3 V
V
INH
, Input High Voltage 3.5 V min DV
DD
= +5 V
V
INH
, Input High Voltage 2.5 V min DV
DD
= +3 V
LOGIC OUTPUTS (Including MCLK OUT)
V
OL
, Output Low Voltage 0.4 V max I
SINK
= 800 µA Except for MCLK OUT
15
.
V
DD
16
= +5 V
V
OL
, Output Low Voltage 0.4 V max I
SINK
= 100 µA Except for MCLK OUT
15
.
V
DD
16
= +3 V
V
OH
, Output High Voltage 4.0 V min I
SOURCE
= 200 µA Except for MCLK OUT
15
.
V
DD
16
= +5 V
V
OH
, Output High Voltage DV
DD
– 0.6 V V min I
SOURCE
= 100 µA Except for MCLK OUT
15
.
V
DD
16
= +3 V
Floating State Leakage Current ±10 µA max
Floating State Output Capacitance
3
6 pF typ
TRANSDUCER BURNOUT
17
AIN1(+) Current –100 nA nom
AIN1(–) Current 100 nA nom
Initial Tolerance @ 25°C ±10 % typ
Drift 0.1 %/°C typ
SYSTEM CALIBRATION
Positive Full-Scale Calibration Limit
18
1.05 × FS V max FS Is the Nominal Full-Scale Voltage (20 mV,
40 mV, 80 mV, 160 mV, 320 mV, 640 mV, 1.28 V)
Negative Full-Scale Calibration Limit
18
–1.05 × FS V max
Offset Calibration Limit
19
–1.05 × FS V min
Input Span
19
0.8 × FS V min
2.1 × FS V max
POWER REQUIREMENTS
Power Supply Voltages
AV
DD
– AGND Voltage +5 V nom
DV
DD
Voltage +2.7 to +5.25 V min to V max With AGND = 0 V
Power Supply Currents External MCLK. Digital I/Ps = 0 V or DV
DD
AV
DD
Current (Normal Mode) 10.3 mA max
DV
DD
Current (Normal Mode) 1.7 mA max DV
DD
of 2.7 V to 3.3 V
DV
DD
Current (Normal Mode) 3.2 mA max DV
DD
of 4.75 V to 5.25 V
AV
DD
+ DV
DD
Current (Standby Mode) 25 µA max Typically 10 µA. External MCLK IN = 0 V or DV
DD
Power Dissipation AV
DD
= DV
DD
= +5 V. Digital I/Ps = 0 V or DV
DD
Normal Mode 67.5 mW max
Standby Mode 125 µW max Typically 50 µW. External MCLK IN = 0 V or DV
DD
REV. A