ADS1285IRHBR

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 7-ppb 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 5-mm × 5-mm VQFN package and is fully specified over the -40°C to +85°C ambient temperature range.

Applications

• Energy exploration
• Passive seismic monitoring
• Earth sciences and geology
• Precision instrumentation

Key features

• Selectable resolution-power modes:
• Dynamic range: 134 dB at 2 ms, 11.5 mW
• Dynamic range: 129 dB at 2 ms, 4.8 mW
• Flexible digital filter:
• Selectable sinc + F|R + I IR
• Linear or minimum phase
• High-pass filter
• THD: < –120 dB
• CMRR: 125 dB
• Data rates: 125 SPS to 4000 SPS
• Programmable gains: 1 to 64
• PGA bypass option
• SYNC input
• Clock error compensation
• Two-channel multiplexer
• Offset and gain calibration
• General-purpose digital I/Os
• Analog supply operation: 5 V, 3.3 V, or ±2.5 V
• Reference voltage options: 5 V, 4.096 V, or 2.5 V