ADS8684IDBT

The ADS8684 and ADS8688 are 4-channel and 8-channel integrated data acquisition systems respectively. They are based on 16-bit successive approximation register (SAR) analog-to-digital converters (ADCs) and can achieve a throughput of up to 500 kSPS during operation. These devices offer an integrated analog front-end circuit for each input channel (with overvoltage protection up to ±20V), a 4-channel or 8-channel multiplexer supporting both automatic and manual scan modes, and an on-chip 4.096V reference voltage with low temperature drift. When powered by a single 5V analog supply, each input channel on the device can support actual bipolar input ranges of ±10.24V, ±5.12V, and ±2.56V, as well as unipolar input ranges of 0V to 10.24V and 0V to 5.12V. The gain of the analog front-end is precisely trimmed across all input ranges to ensure high DC accuracy. The input range can be selected through software programming, and the input range selection for each channel is independent. The device provides a constant resistive input impedance of 1MΩ (regardless of the selected input range). The ADS8684 and ADS8688 offer a simple SPI-compatible serial interface for connecting to a digital host and support connecting multiple devices in a daisy-chain configuration. The digital power supply can provide voltages in the range of 1.65V to 5.25V, enabling direct connection to various host controllers.

Applications

• Power Automation
• Protection Relays
• PLC Analog Input Modules

Key features

• 16-bit ADC with integrated analog front end
• 4-channel and 8-channel MUX supporting automatic and manual scan modes
• Bipolar: ±10.24V, ±5.12V, and ±2.56V; Unipolar: 0V to 10.24V and 0V to 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
• Total throughput: 500kSPS
• DNL: ±0.5 LSB; max INL: ±0.75 LSB
• Low drift gain error and offset error
• SNR: 92dB; THD: –102dB
• Low power consumption: 65mW
• AUX input ⟶ direct connection to ADC input
• SPI-compatible interface with daisy-chain support
• Industrial temperature range: -40°C to 125°C
• TSSOP-38 package (9.7mm×4.4mm)