AD7799 Analog Devices, AD7799 Datasheet - Page 5

• Manufacturer Part Number: AD7799
• Description: 3-Channel, Low Noise, Low Power, 24-Bit, Sigma Delta ADC with On-Chip In-Amp
• Manufacturer: Analog Devices

Specifications of AD7799

• Resolution (bits): 24bit
• # Chan: 3
• Sample Rate: n/a
• Interface: Ser,SPI
• Analog Input Type: Diff-Uni
• Ain Range: (2Vref/PGA Gain) p-p
• Adc Architecture: Sigma-Delta
• Pkg Type: SOP

Parameter
SYSTEM CALIBRATION
POWER REQUIREMENTS
1
2
3
4
5
6
7
Temperature range is –40°C to +105°C. At the 19.6 Hz and 39.2 Hz update rates, the INL, power supply rejection (PSR), common-mode rejection (CMR), and normal
mode rejection (NMR) do not meet the data sheet specification if the voltage on the AIN(+) or AIN(−) pins exceeds AV
exceeded, the INL, for example, is reduced to 18 ppm of FS typically and the PSR is reduced to 69 dB typically. Therefore, for guaranteed performance at these update
rates, the absolute voltage on the analog input pins needs to be below AV
Specification is not production tested, but is supported by characterization data at initial product release.
Following a calibration, this error is in the order of the noise for the programmed gain and update rate selected.
Recalibration at any temperature removes these errors.
Full-scale error applies to both positive and negative full-scale and applies at the factory calibration conditions (AV
FS[3:0] are the four bits used in the mode register to select the output word rate.
Digital inputs equal to DV
Full-Scale Calibration Limit
Zero-Scale Calibration Limit
Input Span
Power Supply Voltage
Power Supply Currents
AV
DV
I
I
DD
DD
DD
DD
Current
(Power-Down Mode)
– GND
– GND
2
DD
7
or GND.
AD7798B/AD7799B
1.05 × FS
−1.05 × FS
0.8 × FS
2.1 × FS
2.7/5.25
2.7/5.25
140
180
400
500
1
Rev. A | Page 5 of 28
DD
1
− 1.6 V.
V min/max
μA max
Unit
V max
V min
V min
V max
V min/max
μA max
μA max
μA max
μA max
Test Conditions/Comments
FS = Full-scale analog input. When V
differential input must be limited to (0.9 × V
if the in-amp is active.
Unbuffered mode, 110 μA typ @ AV
125 μA typ @ AV
Buffered mode, gain = 1 or 2, 130 μA typ @ AV
165 μA typ @ AV
AD7798: gain = 4 to 128, 300 μA typ @ AV
350 μA typ @ AV
AD7799: gain = 4 to 128, 380 μA typ @ AV
440 μA typ @ AV
DD
= 4 V, gain = 1, T
DD
− 1.6 V typically. When this voltage is
DD
DD
DD
DD
= 5 V
= 5 V
= 5 V
= 5 V
A
= 25°C).
AD7798/AD7799
DD
REF
= 3 V,
= AV
REF
DD
DD
/gain)
DD
= 3 V,
= 3 V,
DD
, the
= 3 V,