16-bit, 500-kSPS, eight-channel, single-supply SAR ADC with ±12-V differential inputs
The ADS8684W and ADS8688W are 4-channel and
8-channel, integrated data acquisition systems based
on a 16-bit successive approximation (SAR) analogto-digital converter (ADC), operating at a throughput
of 500kSPS. The devices feature integrated analog
front-end circuitry for each input channel with
overvoltage protection up to ±20V, a 4-channel or
8-channel multiplexer with automatic and manual
scanning modes, and an on-chip, 4.096V reference
with low temperature drift. Operating on a single 5V
analog supply, each input channel on the devices
can independently support bipolar input ranges of
±12.288V, ±6.144V, and ±3.072V and unipolar input
ranges of 12.288V to 0V and 6.144V to 0V.
The ADS8684W and ADS8688W offer a simple SPIcompatible serial interface to the digital host and also
support daisy-chaining of multiple devices. The digital
supply operates from 1.65V to 5.25V, enabling direct
interface to a wide range of host controllers
Features
• 16-Bit ADCs with Integrated Analog Front-End
• 4-, 8-Channel MUX with Auto and Manual Scan
• Channel-Independent Programmable Inputs:
– ±12.288V, ±6.144V, and ±3.072V
– 12.288V to 0V and 6.144V to 0V
• 5V Analog Supply: 1.65V to 5V I/O Supply
• Constant Resistive Input Impedance: 1.2MΩ
• Input Overvoltage Protection: Up to ±20V
• On-Chip, 4.096V Reference with Low Drift
• Excellent Performance:
– 500kSPS Aggregate Throughput
– DNL: ±0.6LSB; INL: ±0.8LSB
– Low Drift for Gain Error and Offset
– SNR: 91.5dB; THD: –102dB
– Low Power: 65mW
• AUX Input → Direct Connection to ADC Inputs
• ALARM → High and Low Thresholds per Channel
• SPI™-Compatible Interface with Daisy-Chain
• Industrial Temperature Range: –40°C to 125°C