Datasheet
ADS131E04
ADS131E06
ADS131E08
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SBAS561A –JUNE 2012–REVISED APRIL 2013
PARAMETER MEASUREMENT INFORMATION
NOISE MEASUREMENTS
The ADS131E0x noise performance can be optimized by adjusting the data rate and PGA setting. As the
averaging is increased by reducing the data rate, the noise drops correspondingly. Increasing the PGA value
reduces the input-referred noise, which is particularly useful when measuring low-level signals. Table 1
summarizes the ADS131E0x noise performance with a 3-V analog power supply. Table 2 summarizes the
ADS131E0x noise performance with a 5-V analog power supply. The data are representative of typical noise
performance at T
A
= +25°C. The data shown are the result of averaging the readings from multiple devices and
are measured with the inputs shorted together. A minimum of 1000 consecutive readings are used to calculate
the RMS and peak-to-peak noise for each reading. For the two highest data rates, the noise is limited by ADC
quantization noise and does not have a Gaussian distribution. Table 1 and Table 2 show measurements taken
with an internal reference. The data are also representative of the ADS131E0x noise performance when using a
low-noise external reference, such as the REF5025.
Table 1. Input-Referred Noise, 3-V Analog Supply, and 2.4-V Reference
(1)
PGA GAIN
OUTPUT
x1 x2 x4 x8 x12
DR BITS DATA –3-dB
(CONFIG1 RATE BANDWIDTH DYNAMIC DYNAMIC DYNAMIC DYNAMIC DYNAMIC
Register) (kSPS) (Hz) RANGE (dB) ENOB RANGE (dB) ENOB RANGE (dB) ENOB RANGE (dB) ENOB RANGE (dB) ENOB
000 64 16768 74.1 12.31 74.1 12.30 74.0 12.29 74.0 12.29 73.9 12.27
001 32 8384 89.6 14.89 89.6 14.88 89.4 14.85 88.6 14.71 87.6 14.55
010 16 4192 102.8 17.07 102.3 16.99 100.6 16.72 97.1 16.12 94.2 15.65
011 8 2096 108.2 18.0 107.4 17.9 105.2 17.5 101.6 16.9 98.9 16.5
100 4 1048 111.4 18.6 109.4 18.4 107.4 18.1 103.5 17.4 100.5 17.0
101 2 524 114.6 19.1 113.7 19.0 111.4 18.6 107.7 18.0 104.9 17.5
110 1 262 117.7 19.6 116.8 19.5 114.5 19.1 110.7 18.5 108.0 18.0
(1) At least 1000 consecutive readings were used to calculate the peak-to-peak noise values in this table.
Table 2. Input-Referred Noise, 5-V Analog Supply, and 4-V Reference
PGA GAIN
OUTPUT
x1 x2 x4 x8 x12
DR BITS DATA –3-dB
(CONFIG1 RATE BANDWIDTH DYNAMIC DYNAMIC DYNAMIC DYNAMIC DYNAMIC
Register) (kSPS) (Hz) RANGE (dB) ENOB RANGE (dB) ENOB RANGE (dB) ENOB RANGE (dB) ENOB RANGE (dB) ENOB
000 64 16768 74.7 12.41 74.7 12.41 74.7 12.41 74.7 12.41 74.6 12.39
001 32 8384 90.3 15.01 90.3 15.00 90.2 14.99 89.9 14.93 89.4 14.85
010 16 4192 104.3 17.33 104.0 17.28 103.1 17.12 100.5 16.70 98.1 16.30
011 8 2096 112.3 18.7 111.6 18.6 109.7 18.3 106.3 17.7 103.8 17.3
100 4 1048 116.0 19.3 115.2 19.2 113.1 18.8 109.5 18.3 106.9 17.8
101 2 524 119.1 19.8 118.2 19.7 116.2 19.4 112.6 18.8 109.9 18.3
110 1 262 122.1 20.4 121.3 20.2 119.1 19.9 115.6 19.3 112.9 18.8
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