Datasheet

REV. A
–3–
AD7719
(AV
DD
= 2.7 V to 3.6 V or 4.75 V to 5.25 V, DV
DD
= 2.7 V to 3.6 V or 4.75 V to 5.25 V,
REFIN(+) = 2.5 V; REFIN(–) = AGND; AGND = DGND = 0 V; XTAL1/XTAL2 = 32.768 kHz Crystal; all specifications T
MIN
to T
MAX
, unless otherwise noted.)
Parameter AD7719B Unit Test Conditions
ADC CHANNEL SPECIFICATION
Output Update Rate 5.4 Hz min Both Channels Synchronized
105 Hz max 0.732 ms Increments
MAIN CHANNEL
No Missing Codes
2
24 Bits min 20 Hz Update Rate
Resolution 13 Bits p-p ±20 mV Range, 20 Hz Update Rate
18 Bits p-p ±2.56 V Range, 20 Hz Update Rate
Output Noise and Update Rates See Tables II to V
Integral Nonlinearity ±10 ppm of FSR max Typically 2 ppm.
Offset Error
3
±3 µV typ
Offset Error Drift vs. Temperature
4
±10 nV/°C typ
Full-Scale Error
5, 6, 7
±10 µV typ At the Calibrated Conditions
Gain Drift vs. Temperature
4
±0.5 ppm/°C typ
Power Supply Rejection (PSR) 80 dB min Input Range = ±2.56 V, 100 dB typ.
110 dB typ on ±20 mV Range
ANALOG INPUTS
Differential Input Voltage Ranges ±1.024 × REFIN1/GAIN V nom REFIN1 = REFIN1(+) – REFIN1(–)
GAIN = 1 to 128.
ADC Range Matching ±2 µV typ Input Voltage = 19 mV on All Ranges
Absolute AIN Voltage Limits AGND + 100 mV V min BUF = 0; Buffered Mode of Operation
AV
DD
– 100 mV V max
Analog Input Current
2
BUF = 0
DC Input Current ±1 nA max
DC Input Current Drift ±5 pA /°C typ
Absolute AIN Voltage Limits AGND – 30 mV V min BUF = 1; Unbuffered mode of operation.
AV
DD
+ 30 mV V max
Analog Input Current BUF = 1. Unbuffered Mode of Operation.
DC Input Current ±125 nA/V typ Input Current Varies with Input Voltage
DC Input Current Drift ±2 pA/V/°C typ
Normal-Mode Rejection
2, 8
@ 50 Hz 100 dB min 50 Hz ± 1 Hz, 16.65 Hz Update Rate, SF = 82
@ 60 Hz 100 dB min 60 Hz ± 1 Hz, 20 Hz Update Rate, SF = 68
Common-Mode Rejection
@ DC 90 dB min Input Range = ±2.56 V, AIN = 1 V.
100 dB typ. 110 dB typ on ±20 mV Range
@ 50 Hz
2
100 dB min 50 Hz ± 1 Hz, Range = ±2.56 V, AIN = 1 V
@ 60 Hz
2
100 dB min 60 Hz ± 1 Hz, Range = ±2.56 V, AIN = 1 V
REFERENCE INPUT (REFIN1)
REFIN1 Voltage 2.5 V nom REFIN1 = REFIN1(+) – REFIN1(–)
REFIN1 Voltage Range
2
1V min
AV
DD
V max
REFIN1 Common-Mode Range AGND – 30 mV V min
AV
DD
+ 30 mV V max
Reference DC Input Current 0.5 µA/V typ
Reference DC Input Current Drift ±0.01 nA/V/°C typ
Normal-Mode Rejection
2, 8
@ 50 Hz 100 dB min 50 Hz ± 1 Hz, SF = 82
@ 60 Hz 100 dB min 60 Hz ± 1 Hz, SF = 68
Common-Mode Rejection
@ DC 110 dB typ Input Range = ±2.56 V, AIN = 1 V
@ 50 Hz 110 dB typ 50 Hz ± 1 Hz, Range = 2.56 V, AIN = 1 V
@ 60 Hz 110 dB typ 60 Hz ± 1 Hz, Range = 2.56 V, AIN = 1 V
Reference Detect Levels 0.3 V min NOXREF Bit Active if VREF < 0.3 V
0.65 V max NOXREF Bit Inactive if VREF > 0.65 V
AUXILIARY CHANNEL
No Missing Codes
2
16 Bits min
Resolution 16 Bits p-p ±2.5 V Range, 20 Hz Update Rate
Output Noise and Update Rates See Tables VI and VIII
Integral Nonlinearity ±15 ppm of FSR max
FSR
REFIN
Gain
=
×21024 1.
–SPECIFICATIONS
1