| Resolution (Bits) | 31 |
| Number of input channels | 1 |
| Sample rate (Max) (kSPS) | 4 |
| Interface type | SPI |
| Architecture | Delta-Sigma |
| Input type | Differential |
| Rating | Catalog |
| Reference mode | Ext |
| Input range (Max) (V) | 2.7, 5 |
| Input range (Min) (V) | -2.7, 0 |
| Operating temperature range (C) | -40 to 85 |
| Power consumption (Typ) (mW) | 12 |
| Analog voltage AVDD (Min) (V) | -2.5, 0 |
| SNR (dB) | 130 |
| Analog voltage AVDD (Max) (V) | 2.5, 5 |
| Digital supply (Min) (V) | 1.65 |
| Digital supply (Max) (V) | 3.6 |
- High Resolution:
- 130dB SNR (250SPS)
- 127dB SNR (500SPS)
- High Accuracy:
- THD: –122dB (typ), –115dB (max)
- INL: 0.6ppm
- Inherently Stable Modulator with Fast Responding Over-Range Detection
- Flexible Digital Filter:
- Sinc + FIR + IIR (Selectable)
- Linear or Minimum Phase Response
- Programmable High-Pass Filter
- Selectable FIR Data Rates:
- 250SPS to 4kSPS
- Filter Bypass Option
- Low Power Consumption:
- Operating: 12mW
- Shutdown: 10μW
- Calibration Engine for Offset and
Gain Correction - SYNC Input
- Analog Supply:
- Unipolar (+5V) or Bipolar (±2.5V)
- Digital Supply: 1.8V to 3.3V
- APPLICATIONS
- Energy Exploration
- Seismic Monitoring
- High-Accuracy Instrumentation
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The ADS1281 is an extremely high-performance, single-chip analog-to-digital converter (ADC) designed for the demanding needs of energy exploration and seismic monitoring environments. The single-chip design promotes board area savings for improvements in high-density applications.
The converter uses a fourth-order, inherently stable, delta-sigma (
) modulator that provides outstanding noise and linearity performance. The modulator is used either in conjunction with the on-chip digital filter, or can be bypassed for use with post-processing filters.
The digital filter consists of sinc and finite impulse response (FIR) low-pass stages followed by an infinite impulse response (IIR) high-pass filter (HPF) stage. Selectable decimation provides data rates from 250 to 4000 samples per second (SPS). The FIR low-pass stage provides both linear and minimum phase response. The HPF features an adjustable corner frequency. On-chip gain and offset scaling registers support system calibration.
The synchronization input (SYNC) can be used to synchronize the conversions of multiple ADS1281s. The SYNC input also accepts a clock input for continuous alignment of conversions from an external source.
Together, the modulator and filter dissipate only 12mW. The ADS1281 is available in a compact TSSOP-24 package and is fully specified from –40°C to +85°C, with a maximum operating range to +125°C.
