SBAS453G July 2009 – August 2016 ADS1146 , ADS1147 , ADS1148
PRODUCTION DATA.
The ADC noise performance is optimized by adjusting the data rate and PGA setting. Generally, the lowest input-referred noise is achieved using the highest gain possible, consistent with the input signal range. Do not set the gain too high or the result is ADC overrange. Noise also depends on the output data rate. As the data rate reduces, the ADC bandwidth correspondingly reduces. This reduction in total bandwidth results in lower overall noise. Table 1 and Table 2 summarize the noise performance of the device. The data are representative of typical noise performance at TA = 25°C. The data shown are the result of averaging the readings from multiple devices and were measured with the inputs shorted together.
Table 1 lists the input-referred noise in units of µVPP for the conditions shown. Table 2 lists the corresponding data in units of ENOB (effective number of bits) where ENOB for the peak-to-peak noise is defined in Equation 1.
where
DATA RATE (SPS) |
PGA SETTING | |||||||
---|---|---|---|---|---|---|---|---|
1 | 2 | 4 | 8 | 16 | 32 | 64 | 128 | |
5 | 62.5(1) | 31.25(1) | 15.63(1) | 7.81(1) | 3.91(1) | 1.95(1) | 0.98(1) | 0.49(1) |
10 | 62.5(1) | 31.25(1) | 15.63(1) | 7.81(1) | 3.91(1) | 1.95(1) | 0.98(1) | 0.49(1) |
20 | 62.5(1) | 31.25(1) | 15.63(1) | 7.81(1) | 3.91(1) | 1.95(1) | 0.98(1) | 0.55 |
40 | 62.5(1) | 31.25(1) | 15.63(1) | 7.81(1) | 3.91(1) | 1.95(1) | 0.98(1) | 0.75 |
80 | 62.5(1) | 31.25(1) | 15.63(1) | 7.81(1) | 3.91(1) | 1.95(1) | 1.09 | 0.98 |
160 | 62.5(1) | 31.25(1) | 15.63(1) | 7.81(1) | 3.91(1) | 1.95(1) | 1.88 | 1.57 |
320 | 62.5(1) | 35.3 | 17.52 | 8.86 | 4.35 | 3.03 | 2.44 | 2.34 |
640 | 93.06 | 45.2 | 18.73 | 12.97 | 6.51 | 4.2 | 3.69 | 3.5 |
1000 | 284.59 | 129.77 | 61.3 | 33.04 | 16.82 | 9.08 | 5.42 | 4.65 |
2000 | 273.39 | 130.68 | 67.13 | 36.16 | 19.22 | 9.87 | 6.93 | 6.48 |
DATA RATE (SPS) |
PGA SETTING | |||||||
---|---|---|---|---|---|---|---|---|
1 | 2 | 4 | 8 | 16 | 32 | 64 | 128 | |
5 | 16 | 16 | 16 | 16 | 16 | 16 | 16 | 16 |
10 | 16 | 16 | 16 | 16 | 16 | 16 | 16 | 16 |
20 | 16 | 16 | 16 | 16 | 16 | 16 | 16 | 15.8 |
40 | 16 | 16 | 16 | 16 | 16 | 16 | 16 | 15.4 |
80 | 16 | 16 | 16 | 16 | 16 | 16 | 15.8 | 15 |
160 | 16 | 16 | 16 | 16 | 16 | 16 | 15.1 | 14.3 |
320 | 16 | 15.8 | 15.8 | 15.8 | 15.8 | 15.4 | 14.7 | 13.7 |
640 | 15.4 | 15.5 | 15.7 | 15.3 | 15.3 | 14.9 | 14.1 | 13.2 |
1000 | 13.8 | 13.9 | 14 | 13.9 | 13.9 | 13.8 | 13.5 | 12.7 |
2000 | 13.9 | 13.9 | 13.9 | 13.8 | 13.7 | 13.7 | 13.2 | 12.3 |