ZHCSIU4A September 2018 – August 2019 ADS1284
PRODUCTION DATA.
The ADS1284 offers outstanding signal-to-noise ratio (SNR). SNR depends on data rate, gain and mode of operation (high resolution or low power). As the bandwidth is reduced by decreasing the data rate, SNR improves correspondingly. Similarly, as gain is increased, the input-referred noise decreases. The low power mode decreases the oversampling ratio of the modulator and reduces the bias current of the PGA. As a consequence, low-power mode reduces the operating power but also results in increased conversion noise. The ADC incorporates a chop mode to remove 1/f noise from the PGA. Chop mode results in increased input current and as a result, chop mode may not be compatible with certain types of hydrophone sensors.
Input-referred noise is related to SNR by Equation 1:
where
Table 1 summarizes SNR and input-referred noise performance in low-power mode (chop enabled). Table 2 summarizes SNR and input-referred noise performance in low-power mode (chop disabled).
DATA RATE (SPS) | PGA (SNR, dB)(1) | PGA (Input-Referred Noise, µV RMS) | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | 2 | 4 | 8 | 16 | 32 | 64 | 1 | 2 | 4 | 8 | 16 | 32 | 64 | |
250 | 127 | 127 | 126 | 124 | 122 | 116 | 111 | 0.79 | 0.41 | 0.22 | 0.14 | 0.09 | 0.09 | 0.08 |
500 | 124 | 124 | 123 | 121 | 119 | 113 | 108 | 1.13 | 0.58 | 0.31 | 0.19 | 0.13 | 0.12 | 0.11 |
1000 | 121 | 121 | 120 | 118 | 116 | 110 | 105 | 1.60 | 0.82 | 0.44 | 0.27 | 0.18 | 0.17 | 0.16 |
2000 | 118 | 118 | 117 | 115 | 113 | 107 | 102 | 2.27 | 1.16 | 0.63 | 0.39 | 0.26 | 0.24 | 0.22 |
4000 | 115 | 114 | 114 | 112 | 110 | 104 | 99 | 3.27 | 1.68 | 0.90 | 0.56 | 0.37 | 0.34 | 0.32 |
DATA RATE (SPS) | PGA (SNR, dB)(1) | PGA (Input-Referred Noise, µV RMS) | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | 2 | 4 | 8 | 16 | 32 | 64 | 1 | 2 | 4 | 8 | 16 | 32 | 64 | |
250 | 127 | 126 | 122 | 119 | 114 | 107 | 102 | 0.82 | 0.47 | 0.34 | 0.25 | 0.22 | 0.24 | 0.23 |
500 | 124 | 123 | 121 | 117 | 113 | 107 | 101 | 1.16 | 0.63 | 0.38 | 0.30 | 0.25 | 0.25 | 0.25 |
1000 | 121 | 120 | 119 | 116 | 112 | 106 | 100 | 1.61 | 0.85 | 0.50 | 0.37 | 0.29 | 0.29 | 0.27 |
2000 | 118 | 118 | 116 | 114 | 110 | 104 | 99 | 2.28 | 1.19 | 0.68 | 0.47 | 0.35 | 0.35 | 0.32 |
4000 | 115 | 114 | 114 | 111 | 108 | 102 | 97 | 3.29 | 1.70 | 0.94 | 0.62 | 0.43 | 0.43 | 0.40 |
Table 3 summarizes SNR and input-referred noise performance in high-resolution mode (chop enabled). Table 4 summarizes SNR and input-referred noise performance in high-resolution mode (chop disabled).
DATA RATE (SPS) | PGA (SNR, dB)(1) | PGA (Input-Referred Noise, µV RMS) | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | 2 | 4 | 8 | 16 | 32 | 64 | 1 | 2 | 4 | 8 | 16 | 32 | 64 | |
250 | 130 | 129 | 129 | 127 | 125 | 119 | 114 | 0.59 | 0.30 | 0.16 | 0.10 | 0.07 | 0.06 | 0.06 |
500 | 127 | 126 | 126 | 124 | 122 | 116 | 111 | 0.84 | 0.43 | 0.23 | 0.14 | 0.09 | 0.09 | 0.08 |
1000 | 124 | 123 | 123 | 121 | 119 | 113 | 108 | 1.19 | 0.60 | 0.32 | 0.20 | 0.13 | 0.12 | 0.11 |
2000 | 121 | 120 | 120 | 118 | 116 | 110 | 105 | 1.68 | 0.86 | 0.46 | 0.28 | 0.18 | 0.17 | 0.16 |
4000 | 117 | 117 | 117 | 115 | 113 | 107 | 102 | 2.40 | 1.22 | 0.66 | 0.40 | 0.26 | 0.25 | 0.23 |
DATA RATE (SPS) | PGA (SNR, dB)(1) | PGA (Input-Referred Noise, µV RMS) | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | 2 | 4 | 8 | 16 | 32 | 64 | 1 | 2 | 4 | 8 | 16 | 32 | 64 | |
250 | 129 | 128 | 125 | 120 | 116 | 110 | 104 | 0.63 | 0.37 | 0.26 | 0.21 | 0.18 | 0.17 | 0.18 |
500 | 126 | 125 | 123 | 119 | 114 | 108 | 103 | 0.87 | 0.47 | 0.31 | 0.25 | 0.21 | 0.21 | 0.20 |
1000 | 123 | 123 | 121 | 117 | 114 | 108 | 102 | 1.20 | 0.65 | 0.39 | 0.30 | 0.22 | 0.22 | 0.22 |
2000 | 120 | 120 | 119 | 116 | 112 | 107 | 101 | 1.69 | 0.91 | 0.51 | 0.37 | 0.26 | 0.25 | 0.25 |
4000 | 117 | 117 | 116 | 114 | 111 | 105 | 99 | 2.41 | 1.24 | 0.70 | 0.46 | 0.33 | 0.31 | 0.30 |