ADS8681IPWR

The ADS8681, ADS8685, and ADS8689 belong to a series of integrated data acquisition systems 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, overvoltage protection circuitry up to ±20V, and an on-chip 4.096V reference with extremely low temperature drift. These devices are powered by a 5V analog supply and support true 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 values to ensure high DC accuracy. The input range can be selected by programming the device's internal registers. These devices offer a high resistive input impedance (≥1MΩ) that is independent of the selected input range. The multiSPI digital interface is backward compatible with the traditional SPI protocol. Additionally, configurable features simplify interfacing with a variety of host controllers.

Applications

• Analog input module
• Semiconductor testing
• Servo drive control module

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
• 4.096V on-chip low-drift voltage reference