AD7172-2 Low Power, 24-Bit, 31.25 kSPS, Sigma-Delta ADC with True Rail-to-Rail Buffers

TThe AD7172-2 is an intelligent, low noise, low power, multiplexed, Σ-Δ analog-to-digital converter (ADC) with 2- or 4-channel (fully differential/single-ended) inputs for low bandwidth signals. The AD7172-2 has a maximum channel scan rate of 6.21 kSPS (161 µs) for fully settled data. The output data rates range from 1.25 SPS to 31.25 kSPS.

The AD7172-2 integrates key analog and digital signal conditioning blocks to allow users 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 external reference inputs provide easy to drive high impedance inputs. The precision 2.5 V low drift (2 ppm/°C) band gap internal reference (with an output reference buffer) adds embedded functionality to reduce the external component count.

The digital filter allows simultaneous 50 Hz and 60 Hz rejection at a 27.27 SPS output data rate. The user can switch between different filter options according to the demands of each channel in the application, with further digital processing functions such as offset and gain calibration registers, which are also configurable on a per channel basis. General-purpose inputs/outputs (GPIOs) control external multiplexers synchronous to the ADC conversion timing.

The specified operating temperature range is −40°C to +105°C. The AD7172-2 is in a 24-lead TSSOP package.

Applications

Features and Benefits

Fast and flexible output rate: 1.25 SPS to 31.25 kSPS

Channel scan data rate of 6.21 kSPS/channel (161 µs settling)

Performance specifications

17.2 noise free bits at 31.25 kSPS

24 noise free bits at 5 SPS

INL: ±2 ppm of FSR

85 dB rejection of 50 Hz and 60 Hz with 50 ms settling

User configurable input channels

2 fully differential channels or 4 single-ended channels

Crosspoint multiplexer

On-chip 2.5 V reference (±2 ppm/°C drift)

True rail-to-rail analog and reference input buffers

Internal or external clock

See data sheet for additional features

Reference Designs

Software & Systems Requirements

AD717x Eval+ Software .ZIP

Data Sheets

Document	note
AD7172-2: Low Power, 24-Bit, 31.25 kSPS, Sigma-Delta ADC with True Rail-to-Rail Buffers Data Sheet (Rev. A)	PDF 1.1 M

User Guides

Document	note
UG-762: Evaluating the AD7172-2 Low Power, 24-Bit, 31.25 kSPS, Sigma-Delta ADC with True Rail-to-Rail Buffers	PDF 795.31 K

Technical Books

Document	note

Order Information

Part Number	Package	Packing Qty	Temp Range	Price 100-499	Price 1000+	RoHS
AD7172-2BRUZ Production	24 ld TSSOP	OTH 62	-40 to 105C	7.42	6.93	Y
AD7172-2BRUZ-RL Production	24 ld TSSOP	REEL 2500	-40 to 105C	0	6.93	Y
AD7172-2BRUZ-RL7 Production	24 ld TSSOP	REEL 1000	-40 to 105C	0	6.93	Y