ADS8689IPWR

The ADS8681, ADS8685, and ADS8689 devices belong to the integrated data acquisition system series and are all based on successive approximation register (SAR) analog-to-digital converters (ADCs). These devices feature a high-speed, high-precision SAR ADC, an integrated analog front-end (AFE) input driver circuit, an overvoltage protection circuit up to ±20V, and an on-chip 4.096V reference with extremely low temperature drift. These devices are powered by a single 5V analog supply, but support actual bipolar input ranges of ±12.288V, ±6.144V, ±10.24V, ±5.12V, and ±2.56V, as well as unipolar input ranges of 0V to 12.288V, 0V to 10.24V, 0V to 6.144V, and 0V to 5.12V. The gain and offset errors for each input range can be adjusted within specific numerical ranges to ensure high DC accuracy. The input range can be selected by programming the internal registers of the device. The device provides a constant resistive input impedance (≥1MΩ), which is unaffected by the selected input range. The multiSPI digital interface is backward-compatible with the traditional SPI protocol. Additionally, the configurable features of the device facilitate connections to various host controllers.

Applications

• Channel-isolated PLC analog input modules
• Test and measurement
• Battery pack monitoring

Key features

• 16-bit ADC with integrated analog front end
• High speed: ADS8681: 1MSPS; ADS8685: 500kSPS; ADS8689: 100kSPS
• Software-programmable input range: Bipolar ranges: ±12.288V, ±10.24V, ±6.144V, ±5.12V, and ±2.56V; Unipolar ranges: 0V–12.288V, 0V–10.24V, 0V–6.144V, and 0V–5.12V
• 5V analog supply, 1.65V to 5V I/O supply
• Constant resistive input impedance ≥ 1MΩ
• Input overvoltage protection: up to ±20V
• Low-drift on-chip 4.096V reference voltage
• Excellent performance: DNL: ±0.4 LSB; INL: ±0.5 LSB; SNR: 92dB; THD: –107dB
• ALARM → per-channel high/low threshold
• multiSPI interface with daisy-chain support