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 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-SP 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 temperature range of –55°C to 125°C and is available in an 84-pin HFQ package.