ADS8688 Data Acquisition Module SAR/ADC Single/Bipolar Analog to Digital

Description

1 Features
· 16-Bit ADCs with Integrated Analog Front-End
· 4, 8-Channel MUX with Auto and Manual Scan
· Channel-Independent Progr ammable Input
Ranges:
– Bipolar: +10.24V, +5.12V, +2.56 V
– Unipolar. 10.24V, 5.12 V
· 5-V Analog Supply: 1.65-V to 5-V VO Supply
· Constant Resistive Input Impedance: 1 MQ
· Input Overvoltage Protection: Up to +20 V
· On-Chip, 4.096-V Reference with Low Drit
· Excellent Perfomance:
– 500-kSPS Aggregate Throughput
– DNL: +0.5 LSB; INL: +0.75 LSB
一L ow Drift for Gain Error and Offset
– SNR: 92 dB; THD: – -102 dB
一LowPower:65mW
· AUX Input – + Direct Connection to ADC Inputs
· SPI-Compatible Interface with Daisy-Chain
· Industrial Temperature Range: – 40°C to 125°C
· TSSOP-38 Package (9.7 mm x 4.4 mm)
2 Applications
· Power Automation
· Protection Relays
· PLC Analog Input Modules
3 Description
The ADS8684 and ADS8688 are 4 and 8-channel, integrated data acquisition systems based on a 16-bit successive approximation (SAR) analog-to-digital
converter (ADC), operating at a throughput of 500-kSPS. The devices feature integrated analog front- end circuitry for each input channel with overvoltage protection up to +20 V, a 4- or 8-channel multiplexer with automatic and manual scanning modes, and an on-chip, 4.096-V reference with low temperature dnift. Operating on a single 5-V analog supply, each input channel on the devices can
support true bipolar input ranges of +10.24 V, +5.12 V, and +2.56 V, as well as unipolar input rangesof0Vto10.24Vand0Vto5.12V.Thegain of the analog front-end for all input ranges is accurately trimmed to ensure a high dc precision. 1 The
input range selection is software-programmable and independent for each channel. The devices offer a 1-MQ constant resistive input impedance irespective of the selected input range. The ADS8684 and ADS8688 offer a simple SPI-compatible serial interface to the digital host and also support daisy-chaining of multiple devices. The digital supply operates from 1.65 V to 5.25 V, enabling direct interface to a wide range of host controllers.