ADS1278-SP - Radiation Hardened 24-Bit 8-Ch Simultaneous-Sampling Delta-Sigma ADC

The ADS1278-SP (octal) is a 24-bit, delta-sigma (ΔΣ) analog-to-digital converter (ADC)with data rates up to 128k samples per second (SPS), allowing simultaneous sampling of eightchannels.

Traditionally, industrial delta-sigma ADCs offering good drift performance use digitalfilters with large passband droop. As a result, they have limited signal bandwidth and are mostlysuited for dc measurements. High-resolution ADCs in audio applications offer larger usablebandwidths, but the offset and drift specifications are significantly weaker than respectiveindustrial counterparts. The ADS1278-SP combines these types of converters, allowing high-precisionindustrial measurement with excellent dc and ac specifications.

The high-order, chopper-stabilized modulator achieves very low drift with low in-bandnoise. The onboard decimation filter suppresses modulator and signal out-of-band noise. These ADCsprovide a usable signal bandwidth up to 90% of the Nyquist rate with less than 0.005 dB ofripple.

Four operating modes allow for optimization of speed, resolution, and power. Alloperations are controlled directly by pins; there are no registers to program. The device is fullyspecified over the extended temperature range of –55°C to 125°C and is available in an 84-pin HFQpackage.

• Radiation Hardened
  • TID 75 krad(Si)
  • TID Radiation Lot Acceptance Test (RLAT) TBD
  • Single Event Latchup (SEL) Immune to LET 68 MeV-cm²/mg @ 125°C
• Simultaneously Samples Eight Channels
• Up to 128-kSPS Data Rate
• AC Performance:
  • 63-kHz Bandwidth
  • 111-dB SNR (High-Resolution Mode)
  • –108-dB THD
• DC Accuracy:
  • 0.8-µV/°C Offset Drift
  • 1.3-ppm/°C Gain Drift
• Selectable 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/ch
• Linear Phase Digital Filter
• SPI™ or Frame-Sync Serial Interface
• Low Sampling Aperture Error
• Modulator Output Option (Digital Filter Bypass)
• Analog Supply: 5 V
• Digital Core: 1.8 V
• I/O Supply: 1.8 V to 3.3 V

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