描述Based on the single-channel ADS1271, the ADS1278 (octal) is a 24-bit, delta-sigma (ΔΣ) analog-to-digital converter (ADC) with data rates up to 128 k samples per second (SPS), allowing simultaneous sampling of eight channels.Traditionally, industrial delta-sigma ADCs offering good drift performance use digital filters with large passband droop. As a result, they have limited signal bandwidth and are mostly suited for dc measurements. High-resolution ADCs in audio applications offer larger usable bandwidths, but the offset and drift specifications are significantly weaker than respective industrial counterparts. The ADS1278 combines these types of converters, allowing high-precision industrial measurement with excellent dc and ac specifications. The high-order, chopper-stabilized modulator achieves very low drift with low in-band noise. The onboard decimation filter suppresses modulator and signal out-of-band noise. These ADCs provide a usable signal bandwidth up to 90% of the Nyquist rate with less than 0.005 dB of ripple. Four operating modes allow for optimization of speed, resolution, and power. All operations are controlled directly by pins; there are no registers to program. The device is fully specified over the extended industrial range (–55°C to 210°C) and is available in an HTQFP-64 PowerPAD package (?55°C to 175°C), an 84-pin HFQ package and a KGD chiptray option.特性Simultaneously Measure Eight ChannelsUp to 128-kSPS Data RateAC Performance: 62-kHz Bandwidth 111-dB SNR (High-Resolution Mode) –108-dB THDDC Accuracy: 0.8-μV/°C Offset Drift 1.3-ppm/°C Gain DriftSelectable Operating Modes: High-Speed: 128 kSPS, 106 dB SNR High-Resolution: 52 kSPS, 111 dB SNR Low-Power: 52 kSPS, 31 mW/ch Low-Speed: 10 kSPS, 7 mW/chLinear Phase Digital FilterSPI or Frame-Sync Serial InterfaceLow Sampling Aperture ErrorModulator Output Option (digital filter bypass)Analog Supply: 5 VDigital Core: 1.8 VI/O Supply: 1.8 V to 3.3 VCurrently Available in an HTQFP-64 PowerPAD? package, an 84-Pin HFQ Package and a KGD Chiptray OptionSupports Extreme Temperature ApplicationsControlled BaselineOne Assembly/Test SiteOne Fabrication SiteAvailable in Extreme (–55°C/210°C) Temperature Range(1)Extended Product Life CycleExtended Product-Change NotificationProduct Traceability Texas Instruments High Temperature Products Utilize Highly Optimized Silicon (Die) Solutions With Dsign and Process Enhancements toMaximize Performance Over Extended TemperaturesAPPLICATIONSDown-Hole DrillingHigh Temperature EnvironmentsVibration/Modal AnalysisMulti-Channel Data AcquisitionAcoustics/Dynamic Strain GaugesPressure Sensors(1) Custom temperature ranges available All other trademarks are the property of their respective owners