Features and Benefits
- 16-bit resolution with no missing codes
- Throughput: 1 MSPS
- Lowpower dissipation
7.0 mW at 1 MSPS (VDD1 and VDD2 only)
12.0 mW at 1 MSPS (total)
140 µW at 10 kSPS
- INL: ±1.0 LSB typical, ±2.5 LSB maximum
- Pseudodifferential analog input range
0 V to VREF with VREF between
2.4 V to 5.1 V
Allows use of any input range
Easy to drive with the ADA4841-1/ADA4841-2
- SINAD: 91 dB at 1 kHz
- THD: −105 dB at 1 kHz
- No pipeline delay
- Single-supply 2.5 V operation with 1.8 V/2.5 V/3 V/5 V logic interface
- Serial port interface (SPI) QSPI/MICROWIRE/DSP compatible
- 20-lead QSOP package
- Wide operating temperature range: −40°C to +125°C
The AD7902 is a dual 16-bit, successive approximation, analog-to-digital converter (ADC) that operates from a single power supply, VDDx, per ADC. It contains two low power, high speed, 16-bit sampling ADCs and a versatile serial port interface (SPI). On the CNVx rising edge, the AD7902 samples an analog input, IN+ in the range of 0 V to VREF with respect to a ground sense, IN−. The externally applied reference voltage of the REFx pins (VREF) can be set independently from the supply voltage pins, VDDx. The power of the device scales linearly with throughput.
Using the SDIx inputs, the SPI-compatible serial interface can also daisy-chain multiple ADCs on a single 3-wire bus and provide an optional busy indicator. It is compatible with 1.8 V, 2.5 V, 3 V, or 5 V logic, using the separate VIOx supplies.
The AD7902 is available in a 20-lead QSOP package with operation specified from −40°C to +125°C.
- Battery-powered equipment
- Automated test equipment (ATE)
- Data acquisition
- Medical instrumentation
- Redundant measurement
- Simultaneous sampling
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 (1)
The EVAL-AD7902SDZ is an evaluation board designed to demonstrate the low power AD7902 performance and to provide an easy to understand interface for a variety of system applications. The AD7902 is a dual pseudo differential 16-bit, 1 MSPS PulSAR® ADC. A full description of the AD7902 is available in the AD7902 data sheet and should be consulted when using this evaluation board.
The evaluation board is ideal for use with the Analog Devices, Inc., system demonstration platform (SDP) board, EVAL-SDP-CB1Z. The evaluation board interfaces to the SDP board via a 120-pin connector. SMA Connectors J6, J10, J14, and J15 are provided to connect a low noise analog signal source.
The user PC software executable controls the evaluation board over the USB through the SDP board, EVAL-SDP-CB1Z.
On-board components include the following:
ADR435: high precision, buffered band gap 5.0 V reference
AD8031: reference buffer
ADA4841-1: signal conditioning circuit with op amps
ADP7104 and ADP2301: regulators to derive necessary voltage levels on board
- Full featured evaluation board for the AD7902
- Versatile analog signal conditioning circuitry
- On-board reference, reference buffers, and ADC drivers
- System demonstration board compatible (EVAL-SDP-CB1Z)
- PC software for control and data analysis of time and frequency domain
Documentation & Resources
SAR ADC & Driver Quick-Match Guide9/13/2013
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
AD7902 Companion Parts
Recommended Digital Isolators
- For SPI Interface, low power, 5.0 kVrms isolation: ADUM4401.
- For SPI Interface, lowest power, 2.5 kVrms isolation: ADUM1401.
- For SPI Interface, smallest package, low voltage I/O (1.8 V to 5.5 V): ADUM3481.
- For SPI Interface, enhanced system-level ESD performance, 2.5 kVrms isolation: ADUM3401.
Recommended External Voltage References
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
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Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.