AD7190 Sigma-Delta Converter

ADI's introduces a Σ-Δ analog-to-digital converter (ADC) that features the industry's best combination of data rate and noise-free resolution. While the resolution of competing devices degrades quickly at speeds beyond 1 kHz, ADI's 24-bit AD7190 Σ-Δ ADC achieves greater than true 16-bit noise-free resolution up to 2.4 kHz across all input voltages from 40 mV to 5 V. This level of performance allows designers to measure much smaller signals faster and with greater accuracy which can significantly improve system performance for precision instruments.

The AD7190 Σ-Δ ADC includes an advanced, on-chip programmable gain amplifier (PGA) with ultra-low noise and drift from dc to 4.8 kHz. The innovative design of the integrated PGA allows the AD7190 Σ-Δ ADC to realize an ultra-low noise of only 7 nV_RMS (root mean squared) at 4.7 Hz data rate with a gain of 128, and an industry-leading offset drift of only 5 nV/°C. In addition to delivering two bits better resolution than competing Σ-Δ ADCs designed to convert small input signals at kHz data rates, the highly integrated AD7190 reduces signal chain cost by up to 25 percent through on-chip features that include an oscillator; temperature sensor; bridge power-down switch; reference detect monitor; and a choice of single-ended, pseudo-differential or fully differential input channels. Also included on-chip are simultaneous 50 Hz and 60 Hz rejection; offset and gain calibration; open sensor detection; a choice of chopped or non-chopped signal; and four general-purpose output pins. A zero-latency mode is selectable in order to reduce software overheads if a valid conversion per data output is desired.