32-bit high-resolution two-channel delta-sigma ADC for seismic and geospace exploration

The ADS1285 is a 32-bit, low-power, analog-to-digital converter (ADC), with a programmable gain amplifier (PGA) and a finite impulse response (FIR) filter. The ADC is designed for the demanding needs of seismology equipment requiring low-noise precision digitization and extended battery run time.

The low-noise PGA allows direct connection of geophones and transformer-coupled hydrophones without the need of an external amplifier.

The ADC incorporates a high-resolution, delta-sigma (ΔΣ) modulator and a FIR filter with programmable phase response. The high-pass filter removes dc and low-frequency content from the signal. Clock frequency error is compensated by the sample rate converter with 7ppb resolution.

Choice of power modes optimize dynamic range verses power consumption. Power consumption is further reduced by PGA bypass operation.

The ADC is available in a compact 5mm × 5mm VQFN package and is fully specified over the –40°C to +85°C ambient temperature range.