4-Channel, Low Noise, Low Power, 24-Bit, Sigma-Delta ADC with PGA and Reference
The AD7124-4 is a low power, low noise, completely integrated analog front end for high precision measurement applications. The device contains a low noise, 24-bit Σ-Δ analog-to-digital converter (ADC), and can be configured to have 4 differential inputs or 7 single-ended or pseudo differential inputs. The onchip low gain stage ensures that signals of small amplitude can be interfaced directly to the ADC.
One of the major advantages of the AD7124-4 is that it gives the user the flexibility to employ one of three integrated power modes. The current consumption, range of output data rates, and rms noise can be tailored with the power mode selected. The device also offers a multitude of filter options, ensuring that the user has the highest degree of flexibility.
The AD7124-4 can achieve simultaneous 50 Hz and 60 Hz rejection when operating at an output data rate of 25 SPS (single cycle settling), with rejection in excess of 80 dB achieved at lower output data rates.
The AD7124-4 establishes the highest degree of signal chain integration. The device contains a precision, low noise, low drift internal band gap reference, and also accepts an external differential reference, which can be internally buffered. Other key integrated features include programmable low drift excitation current sources, burnout currents, and a bias voltage generator, which sets the common-mode voltage of a channel to AVDD/2. The low-side power switch enables the user to power down bridge sensors between conversions, ensuring the absolute minimal power consumption of the system. The device also allows the user the option of operating with either an internal clock or an external clock.
The integrated channel sequencer allows several channels to be enabled simultaneously, and the AD7124-4 sequentially converts on each enabled channel, simplifying communication with the device. As many as 16 channels can be enabled at any time; a channel being defined as an analog input or a diagnostic such as a power supply check or a reference check. This unique feature allows diagnostics to be interleaved with conversions.
The AD7124-4 also supports per channel configuration. The device allows eight configurations or setups. Each configuration consists of gain, filter type, output data rate, buffering, and reference source. The user can assign any of these setups on a channel by channel basis.
The AD7124-4 also has extensive diagnostic functionality integrated as part of its comprehensive feature set. These diagnostics include a cyclic redundancy check (CRC), signal chain checks, and serial interface checks, which lead to a more robust solution. These diagnostics reduce the need for external components to implement diagnostics, resulting in reduced board space needs, reduced design cycle times, and cost savings. The failure modes effects and diagnostic analysis (FMEDA) of a typical application has shown a safe failure fraction (SFF) greater than 90% according to IEC 61508.
The device operates with a single analog power supply from 2.7 V to 3.6 V or a dual 1.8 V power supply. The digital supply has a range of 1.65 V to 3.6 V. It is specified for a temperature range of −40°C to +105°C. The AD7124-4 is housed in a 32-lead LFCSP package or a 24-lead TSSOP package.
Note that, throughout this data sheet, multifunction pins, such as DOUT/RDY, are referred to either by the entire pin name or by a single function of the pin, for example, RDY, when only that function is relevant.Applications
- Temperature measurement
- Pressure measurement
- Industrial process control
- Instrumentation Smart transmitters
- Smart transmitters
This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.
The EVAL-AD7124-4SDZ software fully configures the AD7124-4 device register functionality and provides dc time domain analysis in the form of waveform graphs, histograms, and associated noise analysis for ADC performance evaluation.
The EVAL-AD7124-4SDZ is an evaluation board that is designed to allow the user to evaluate the features of the ADC. The user PC software executable controls the AD7124-4 over the USB through the system demonstration platform board (EVAL-SDP-CB1Z).
Virtual Eval - BETA
Virtual Eval is a web application to assist designers in product evaluation of ADCs and DACs. Using detailed models on Analog’s servers, Virtual Eval simulates crucial part performance characteristics within seconds. Configure operating conditions such as input tones and external jitter, as well as device features like gain or digital down-conversion. Performance characteristics include noise, distortion, and resolution, FFTs, timing diagrams, frequency response plots, and more.
Recommended Digital Isolators
- For SPI Interface , we recommend the ADUM1441 .
Recommended External Precision Reference
- For low noise, high accuracy, 2.5V reference , we recommend the ADR4525 .
Recommended Power Isolators
- For power isolation , we recommend the ADUM5010 .
Recommended Power Solutions
For selecting voltage regulator products, use ADIsimPower.
ADC Requirements for RTD Temperature Measurement Systems
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ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
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The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.