The ADS8661 and ADS8665 belong to a family of integrated
data acquisition system based on a successive approximation (SAR) analog-to-digital converter
(ADC). The devices feature a high-speed, high-precision SAR ADC, integrated analog front-end (AFE)
input driver circuit, overvoltage protection circuit up to ±20 V, and an on-chip
4.096-V reference with extremely low temperature drift.
The devices operate on a single 5-V analog supply, but 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 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 internal registers. The devices offer a high resistive input
impedance (≥ 1 MΩ) irrespective of the selected input range.
The multiSPI digital interface is backward-compatible to the traditional SPI protocol.
Additionally, configurable features simplify interface to a wide range of host controllers.