ZHCSSI3 February 2024 ADS1288
PRODUCTION DATA
The ADS1288 is a low-power, low-noise, delta-sigma ADC operating on the principle of oversampling. Oversampling averages the high-frequency data of the modulator to produce the final output data. Increasing the oversampling ratio lowers the data rate, the corresponding signal bandwidth, and total noise by averaging more samples from the modulator to yield one conversion result.
The gain of the PGA reduces noise when the noise value is referred to the input. With increased gain, dynamic range performance decreases because the ratio of the input voltage range to the input-referred voltage noise also decreases.
Dynamic range and input noise are equivalent parameters that describe the available resolution of the ADC. Equation 1 derives dynamic range from the input-referred noise data:
where:
GAIN | MODE | DYNAMIC RANGE (dB) | en, INPUT-REFERRED NOISE (μVRMS) | ||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
fDATA (SPS) | fDATA (SPS) | ||||||||||
125 | 250 | 500 | 1000 | 2000 | 125 | 250 | 500 | 1000 | 2000 | ||
1 | Buffer | 128 | 125 | 122 | 119 | 116 | 0.70 | 0.99 | 1.4 | 2.0 | 2.8 |
1(1) | PGA | 128 | 125 | 122 | 119 | 116 | 0.70 | 0.99 | 1.4 | 2.0 | 2.8 |
2 | PGA | 127 | 124 | 121 | 118 | 115 | 0.39 | 0.56 | 0.79 | 1.1 | 1.6 |
4 | PGA | 126 | 123 | 120 | 117 | 114 | 0.23 | 0.32 | 0.45 | 0.63 | 0.89 |
8 | PGA | 123 | 120 | 117 | 114 | 111 | 0.16 | 0.22 | 0.31 | 0.44 | 0.62 |
16 | PGA | 118 | 115 | 112 | 109 | 106 | 0.14 | 0.20 | 0.28 | 0.39 | 0.55 |
32 | PGA | 112 | 109 | 106 | 103 | 100 | 0.14 | 0.20 | 0.28 | 0.39 | 0.55 |
64 | PGA | 106 | 103 | 100 | 97 | 94 | 0.14 | 0.20 | 0.28 | 0.39 | 0.55 |