Texas Instruments' ADS8681 is an integrated data acquisition system based on a 16-bit, successive approximation (SAR) analog-to-digital converter (ADC), operating at a throughput of 1 MSPS. The device features a high-precision SAR ADC, integrated analog front-end (AFE) input driver circuit, over-voltage protection circuit up to ±20 V, and an on-chip 4.096 V reference with an extremely low temperature drift. Operating on a single 5 V analog supply, the ADS8681 can support true bipolar input ranges of ±12.288 V, ±6.144 V, ±10.24 V, ±5.12 V, and ±2.56 V, as well as unipolar input ranges of 0 V to 12.288 V, 0 V to 10.24 V, 0 V to 6.144 V, and 0 V to 5.12 V. The gain and offset errors for the AFE circuit are accurately trimmed within the specified values for each input range to ensure high DC precision. The input range selection is done by software programming of the device's internal registers. The device offers a high resistive input impedance (≥ 1 MΩ) irrespective of the selected input range.
The ADS8681 offers an enhanced SPI™-compatible serial interface (multiSPI™) to the digital host and also supports daisy-chaining of multiple devices. The digital supply can operate from 1.65 V to 5.25 V, enabling direct interfacing to a wide range of host controllers.
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- 16-bit ADC with integrated analog front-end
- Software-programmable input ranges:
- Bipolar ranges: ±12.288 V, ±10.24 V, ±6.144 V, ±5.12 V, and ±2.56 V
- Unipolar ranges: 0 V to 12.288 V, 0 V to 10.24 V, 0 V to 6.144 V, and 0 V to 5.12 V
- 5 V analog supply: 1.65 V to 5 V I/O supply
- Constant resistive input impedance: ≥ 1 MΩ
- Input over-voltage protection: up to ±20 V
- On-chip, 4.096 V reference with low drift
- ALARM → high, low thresholds per channel
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- Excellent performance:
- Aggregate throughput: 1 MSPS
- DNL: ±0.4 LSB; INL: ±0.5 LSB
- SNR: 92 dB; THD: -107 dB
- multiSPI interface with daisy-chain
- Industrial temperature range: -40°C to 125°C
- Packages:
- 16-pin TSSOP (5 mm x 4.4 mm)
- 16-pin WQFN (4 mm x 4 mm)
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