Analog Devices Inc. AD7175 24-Bit, 250kSPS Sigma Delta ADCs
Analog Devices Inc. AD7175 24-Bit, 250kSPS Sigma Delta Analog-to-Digital Converters (ADC) are designed as low noise, fast settling, multiplexed, 2-/4- channel (fully/pseudo differential) Σ-Δ ADCs for low bandwidth inputs. AD7175 offers a maximum channel scan rate of 50kSPS (20μs) for fully settled data. The output data rates range from 5SPS to 250kSPS.
Featuring key analog and digital signal conditioning blocks, AD7175 enables designers to configure an individual setup for each analog input channel in use. In addition, designers can select each feature on a per channel basis. Integrated true rail-to-rail buffers on the analog inputs and external reference inputs provide easy to drive high impedance inputs. The precision 2.5V low drift (2 ppm/°C) band gap internal reference (with output reference buffer) adds embedded functionality to reduce external component count. The digital filter allows simultaneous 50Hz/60Hz rejection at 27.27SPS output data rate.
The designer can switch between different filter options according to the demands of each channel in the application. The ADCs automatically switch through each selected channel. Further digital processing functions include offset and gain calibration registers, configurable on a per channel basis.
Capable of operating with 5V AVDD1, or ±2.5V AVDD1/AVSS, and 2V to 5V AVDD2 and IOVDD supplies in a temperature range of −40°C to +105°C, the Analog Devices AD7175 Sigma Delta ADCs are well-suited for PLC/DCS modules in process control, temperature & pressure measurement, medical & scientific multichannel instrumentation, and chromatography.
Features
- Fast and flexible output rate: 5SPS to 250kSPS
- Channel scan data rate of 50kSPS/channel (20μs settling)
- Performance Specifications
- 17.2 Noise Free Bits @ 250kSPS
- 20 Noise Free Bits @ 2.5kSPS
- 24 Noise Free Bits@ 20SPS
- INL: ±1ppm of FSR
- 85dB rejection of 50Hz and 60Hz with 50ms settling
- User configurable input channels
- 2 fully differential channels or 4 single-ended channels
- Crosspoint multiplexer
- On-chip 2.5V reference (±2ppm/°C drift)
- True rail-to-rail analog and reference input buffers
- Internal or external clock
- Power supply: AVDD1 = 5V, AVDD2 = IOVDD = 2V to 5V
- Split supply with AVDD1/AVSS at ±2.5V
- 8.4mA ADC current
- −40°C to +105°C Temperature range
- 3- or 4-wire serial digital interface (Schmitt trigger on SCLK)
- Serial port interface (SPI), QSPI, MICROWIRE, and DSP compatible
Applications
- Process control: PLC/DCS modules
- Temperature and pressure measurement
- Medical and scientific multi-channel instrumentation
- Chromatography
Block Diagram
Associated Dev Tools
Analog Devices Inc. EVAL-SDP-CB1Z System Demonstration Platform
Provides a means of communicating w/PC from the system under evaluation.