Features and Benefits
- Pin and software compatible with AD7656 / AD7657 / AD7658 featuring reduced decoupling requirements
- 6 independent ADCs
- True bipolar analog inputs
- Pin-/software-selectable ranges: ±10 V, ±5 V
- Fast throughput rate: 250 kSPS
- iCMOS process technology
- Low power
140 mW at 250 kSPS with 5 V supplies
- See Data Sheet for Additional Information
The AD7656-1 / AD7657-1 / AD7658-1 are reduced decoupling pin- and software-compatible versions of AD7656 / AD7657 / AD7658. The AD7656-1 / AD7657-1 / AD7658-1 devices contain six 16-/ 14-/12-bit, fast, low power successive approximation ADCs in a package designed on the iCMOS® process (industrial CMOS). iCMOS is a process combining high voltage silicon with submicron CMOS and complementary bipolar technologies. It enables the development of a wide range of high performance analog ICs capable of 33 V operation in a footprint that no previous generation of high voltage parts could achieve. Unlike analog ICs using conventional CMOS processes, iCMOS components can accept bipolar input signals while providing increased performance, which dramatically reduces power consumption and package size.
The AD7656-1 / AD7657-1 / AD7658-1 feature throughput rates of up to 250 kSPS. The parts contain low noise, wide bandwidth track-and-hold amplifiers that can handle input frequencies up to 4.5 MHz.
The conversion process and data acquisition are controlled using the CONVST signals and an internal oscillator. Three CONVST pins (CONVST A, CONVST B, and CONVST C) allow independent, simultaneous sampling of the three ADC pairs. The AD7656-1 / AD7657-1 / AD7658-1 have a high speed parallel and serial interface, allowing the devices to interface with microprocessors or DSPs. When the serial interface is selected, each part has a daisy-chain feature that allows multiple ADCs to connect to a single serial interface. The AD7656-1 / AD7657-1 / AD7658-1 can accommodate true bipolar input signals in the ±4 × VREF and ±2 × VREF ranges. Each AD7656-1 / AD7657-1 / AD7658-1 also contains an on-chip 2.5 V reference.
- Six 16-/14-/12-bit, 250 kSPS ADCs on board.
- Six true bipolar, high impedance analog inputs.
- High speed parallel and serial interfaces.
- Reduced decoupling requirements and reduced bill of materials cost compared with the AD7656 / AD7657 / AD7658 devices.
- Power line monitoring and measuring systems
- Instrumentation and control systems
- Multiaxis positioning systems
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-AD7656-1SDZ is a fully featured evaluation kit for the AD7656-1. This board operates in standalone 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 SDP Controller board is a separate list item in the ordering guide below (EVAL-SDP-CB1Z). If you have not previously purchased an SDP Controller board, please do so to ensure a full evaluation setup.
Documentation & Resources
Successive-Approximation ADCs: Ensuring a Valid First Conversion12/1/2013 Analog Dialogue
ADuC7026 Provides Programmable Voltages for Evaluating Multiple Power Supply Systems8/1/2012 Analog Dialogue
Designing Power Supplies for High Speed ADC2/1/2012
Software & Systems Requirements
AD7656-1 Companion Parts
Recommended High Accuracy, Precision References - 2.5V
- For high accuracy, low noise, low temperature drift: ADR421, ADR431.
- For applications requiring the lowest noise performance and output trim adjust: ADR441.
- For wide supply applications: AD780.
- For cost sensitive applications: AD1582, ADR391.
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.
Support & Discussions
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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.