Analog Devices Inc. AD7173-8 Low-Power Sigma-Delta ADCs

Analog Devices AD7173-8 Low-Power Sigma-Delta ADCs are fast settling, highly accurate, 8-/16-channel, multiplexed ADCs designed for low bandwidth input signals with integrated input buffers. These ADCs feature an integrated precision, 2.5V, 3.5ppm/°C low drift, band gap reference, and an integrated oscillator. The design also includes integrated diagnostic features such as CRC, temperature sensor, register checksum, burnout currents, crosspoint multiplexer, and GPIOs/GPOs. Designers can choose eight different setups for the Analog Devices AD7173-8 ADCs. The setups are configurable by options such as output data rate, buffer, digital filter mode, offset/gain error correction, and reference selection. The ADCs' Sinc5 + sinc1 filter maximizes the channel scan rate. AD7173-8's sinc3 filter maximizes the resolution and enhanced 50Hz/60Hz rejection. These ADCs include four selectable options to maximize rejection.

Features

Low power, 8-/16-channel, highly integrated multiplexed analog-to-digital converter (ADC)
Integration
- Precision analog input buffers and reference input buffers
- 2.5V precision reference (3.5ppm/°C)
- Crosspoint multiplexer(enable system diagnostic)
- 8 full differential or 16 single-ended channels
- Clock oscillator
- GPIO and GPO pins with automatic external mux control
1.25SPS to 31.25kSPS output rate
6.21kSPS/channel (161μs settling) channel scan data rate
-40°C to +105°C temperature range
40-lead 6mm × 6mm LFCSP package
1.4mA current rating

Performance specifications
- 17.5 noise-free bits at 31.25kSPS
- 24 noise-free bits at 1.25SPS
- INL: ±3ppm/FSR
85dB rejection of 50Hz and 60Hz with 50ms settling
Operates with either 3.3V or 5V supply
- Single supply
  - 3.3V or 5V AVDD1, 2V to 5V AVDD2, and 2V to 5V IOVDD
- Optional split supply
  - AVDD1 and AVSS ±2.5V or AVDD1 and AVSS ±1.65V
3-/4-wire serial digital interface (Schmitt trigger on SCLK)
- CRC error checking
- SPI, QSPI, MICROWIRE, and DSP compatible