Features and Benefits
- 14-bit resolution with no missing codes
- Throughput: 250 kSPS
- INL: ±0.4 LSB typical, ±1 LSB maximum (±0.0061% of FSR)
- SINAD: 85 dB @ 20 kHz
- THD: −100 dB @ 20 kHz
- Pseudo differential analog input range
0 V to VREF with VREF up to VDD
- No pipeline delay
- See Data Sheet for Additional Information
The AD7942 is a 14-bit, charge redistribution, successive approximation PulSAR® ADC that operates from a single power supply, VDD, between 2.3 V to 5.5 V. It contains a low power, high speed, 14-bit sampling ADC with no missing codes, an internal conversion clock, and a versatile serial interface port. The part also contains a low noise, wide bandwidth, short aperture delay track-and-hold circuit. On the CNV rising edge, it samples an analog input, IN+, between 0 V to VREF with respect to a ground sense, IN−. The reference voltage, VREF, is applied externally and is set up to be the supply voltage. Its power scales linearly with the throughput.
The SPI-compatible serial interface also features the ability, using the SDI input, to daisy-chain several ADCs on a single 3-wire bus and provides an optional busy indicator. It is compatible with 1.8 V, 2.5 V, 3 V, or 5 V logic using a separate supply (VIO).
The AD7942 is housed in a 10-lead MSOP or a 10-lead LFCSP package yet fits in the same size footprint as the 8-lead MSOP or SOT-23. Operation for the AD7942 is specified from −40°C to +85°C.
- Battery-powered equipment
- Data acquisition
- Medical instruments
- Process controls
Markets and Technologies
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (2)
The EVAL-AD7942SDZ is a fully featured evaluation kit for the AD7942. This board operates in stand alone mode or in conjunction with the System Development Platform, EVAL-SDP-CB1Z . When operated with the System Development Platform software is provided enabling the user to perform detailed analysis of the ADC's performance. This software includes the technical note describing the operation and set up of the evaluation board in standalone operation or when operated with the System Development Platform . When operated in standalone mode the ADZS-BRKOUT-EX3 break out board is recommended for access to various control pins.
The PMOD-compatible evaluation/prototyping board is a small form factor, low-cost analog-to-digital conversion option. When prototyping, this board is used in conjunction with your favorite MCU or FPGA development board which has the SPI PMOD peripheral connector. Direct electrical and physical connection will enable you to quickly develop software for your system.
This board can also be operated as an evaluation board using the System Demonstration Platform (EVAL-SDP-CB1Z) and an adaptor board (SDP-PMD-IB1Z). When operated with the System Demonstration Platform, a LabView software GUI is provided enabling the user to perform analysis of the ADC's performance.
Software & Systems Requirements
Tools & Simulations
Precision ADC Driver Tool
The Precision ADC Driver Tool is a web application that simulates the performance of precision ADC and driver combinations. Potential issues with driver selection, kickback settling, and distortion are flagged, and design tradeoffs can be quickly evaluated. Simulations and calculations include system noise, distortion, and settling of the ADC input
AD7685 IBIS Models
AD7942 Companion Parts
Recommended Digital Isolators
- For SPI Interface, smallest package, low voltage I/O (1.8 V to 5.5 V): ADUM3481.
- For SPI Interface, lowest power, 2.5 kVrms isolation: ADUM1401.
- For SPI Interface, enhanced system-level ESD performance, 2.5 kVrms isolation: ADUM3401.
- For SPI Interface, low power, 5.0 kVrms isolation: ADUM4401.
Recommended Driver Amplifiers
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.
Sample & Buy
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.
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