Analog Devices Inc. AD7172-4 Low Power Sigma-Delta ADCs
Analog Devices AD7172-4 low power sigma-delta analog-to-digital converters (ADC) are low-power, multiplexed, Σ-Δ ADCs with 4- or 8-channel (fully differential/single-ended) inputs for low bandwidth signals. The AD7172-4 has a maximum channel scan rate of 6.21kSPS (161μs) for fully settled data. The output data rates range from 1.25SPS to 31.25kSPS.
The AD7172-4 ADCs integrate key analog and digital signal conditioning blocks to allow designers to configure an individual setup for each analog input channel in use via the SPI. Integrated true rail-to-rail buffers on the analog inputs and reference inputs provide easy-to-drive high impedance inputs. AD7172-4's digital filter enables simultaneous 50Hz and 60Hz rejection at a 27.27SPS output data rate. The designer can switch between different filter options according to the demands of each channel in the application. Additional digital processing functions such as offset and gain calibration registers are configurable on a per-channel basis. General-purpose input/outputs (GPIOs) control external multiplexers synchronous to the ADC conversion timing.
Available in a 5mm × 5mm, 32-lead LFCSP package and specified for an operating temperature range of 40°C to +105°C, the AD7172-4 ADCs are well-suited for PLC/DCS modules for process control, temperature & pressure measurement, medical & scientific multi-channel instrumentation, and chromatography.
Analog Devices offers the EVAL-AD7172-4SDZ evaluation kit to help designers evaluate the features of the AD7172-4 ADC.
Features
- Fast and flexible output rate: 1.25SPS to 31.25kSPS
- Channel scan data rate of 6.21kSPS/channel (161μs settling)
- Performance specifications
- 17.2 noise-free bits at 31.25kSPS
- 24 noise-free bits at 5SPS
- INL: ±2ppm of FSR
- 85dB rejection of 50Hz and 60Hz with 50ms settling
- User-configurable input channels
- 4 fully-differential channels or 2 single-ended channels
- Crosspoint multiplexer
- Internal or external clock
- True rail-to-rail analog and reference input buffers
- Power supply
- AVDD1 = 3.0V to 5.5V, AVDD2 = IOVDD = 2V to 5.5V
- Split supply with AVDD1 and AVSS at ±2.5V or ±1.65V
- ADC current: 1.5mA
- Temperature range: −40°C to +105°C
- 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
Functional Block Diagram
Related Products
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Provides a complete integrated ∑-Delta ADC solution for high-precision, low-noise applications.