AD7785BRUZ Analog Devices Inc, AD7785BRUZ Datasheet - Page 11

• Manufacturer Part Number: AD7785BRUZ
• Description: IC ADC 20BIT SIGMA-DELTA 16TSSOP
• Manufacturer: Analog Devices Inc

Specifications of AD7785BRUZ

• Data Interface: MICROWIRE™, QSPI™, Serial, SPI™
• Number Of Bits: 20
• Sampling Rate (per Second): 470
• Number Of Converters: 1
• Voltage Supply Source: Analog and Digital
• Operating Temperature: -40°C ~ 105°C
• Mounting Type: Surface Mount
• Package / Case: 16-TSSOP (0.173", 4.40mm Width)
• Resolution (bits): 20bit
• Input Channel Type: Differential
• Supply Voltage Range - Analogue: 2.7V To 5.25V
• Supply Voltage Range - Digital: 2.7V To 5.25V
• Supply: RoHS Compliant
• Sampling Rate: 470Hz
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: EVAL-AD7785EBZ - BOARD EVALUATION FOR AD7785
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

OUTPUT NOISE AND RESOLUTION SPECIFICATIONS
EXTERNAL REFERENCE
Table 5 shows the output rms noise of the AD7785 for some of
the update rates and gain settings. The numbers given are for
the bipolar input range with an external 2.5 V reference. These
numbers are typical and are generated with a differential input
voltage of 0 V. Table 6 shows the effective resolution, with the
output peak-to-peak (p-p) resolution shown in parentheses. It is
Table 5. Output RMS Noise (μV) vs. Gain and Output Update Rate Using an External 2.5 V Reference
Update Rate (Hz)
4.17
8.33
16.7
33.2
62
123
242
470
Table 6. Typical Resolution (Bits) vs. Gain and Output Update Rate Using an External 2.5 V Reference
Update Rate (Hz)
4.17
8.33
16.7
33.2
62
123
242
470
Gain of 1
0.64
1.04
1.55
2.3
2.95
4.89
11.76
11.33
Gain of 1
20 (20)
20 (19.5)
20 (19)
20 (18.5)
20 (18)
20 (17.5)
18.5 (16)
18.5 (16)
Gain of 2
0.6
0.96
1.45
2.13
2.85
4.74
9.5
9.44
Gain of 2
20 (19.5)
20 (19)
20 (18)
20 (17.5)
19.5 (17)
19 (16.5)
18 (15.5)
18 (15.5)
Gain of 4
0.29
0.38
0.54
0.74
0.92
1.49
4.02
3.07
Gain of 4
20 (19.5)
20 (19)
20 (18.5)
20 (18)
20 (18)
19.5 (17)
18 (15.5)
18.5 (16)
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Gain of 8
Gain of 8
20 (17.5)
0.22
0.26
0.36
0.5
0.58
1
1.96
1.79
20 (19)
20 (18.5)
20 (18)
20 (17.5)
19 (16.5)
18 (15.5)
18.5 (16)
important to note that the effective resolution is calculated
using the rms noise, while the p-p resolution is based on the p-p
noise. The p-p resolution represents the resolution for which
there is no code flicker. These numbers are typical and are
rounded to the nearest LSB.
Gain of 16
Gain of 16
20 (17.5)
0.1
0.13
0.18
0.23
0.29
0.48
0.88
0.99
20 (19)
20 (18.5)
20 (18)
20 (18)
19.5 (17)
18.5 (16)
18 (15.5)
Gain of 32
0.065
0.078
0.11
0.17
0.2
0.32
0.45
0.63
Gain of 32
20 (18.5)
20 (18.5)
20 (18)
20 (17.5)
19.5 (17)
19 (16.5)
18.5 (16)
18 (15.5)
Gain of 64
0.039
0.057
0.087
0.124
0.153
0.265
0.379
0.568
Gain of 64
20 (18.5)
20 (18)
20 (17.5)
19 (16.5)
19 (16.5)
18 (15.5)
17.5 (15)
17 (14.5)
Gain of 128
Gain of 128
0.041
0.055
0.086
0.118
0.144
0.283
0.397
0.593
20 (17.5)
19.5 (17)
19 (16.5)
18.5 (16)
18 (15.5)
17 (14.5)
16.5 (14)
16 (13.5)
AD7785