The AD7687 is a 16-bit, charge redistribution, successive approximation, analog-to-digital converter (ADC) that operates from a single power supply, VDD, between 2.3 V to 5.5 V. It contains a low power, high speed, 16-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 the voltage difference between IN+ and IN− pins. The voltages on these pins usually swing in opposite phase between 0 V to REF. The reference voltage, REF, is applied externally and can be set up to the supply voltage.
Its power scales linearly with 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 the separate supply VIO.
The AD7687 is housed in a 10-lead MSOP or a 10-lead QFN (LFCSP) with operation specified from −40°C to +85°C.
|Title||Content Type||File Type|
|AD7687: 16-Bit, 1.5 LSB INL, 250 kSPS PulSAR Differential ADC in MSOP/QFN Data Sheet (Rev B, 08/2011) (pdf, 723 kB)||Data Sheets|
|Tested ADC Driver to PulSAR ADC||Application Notes||HTML|
|AN-1141: Powering a Dual Supply Precision ADC with Switching Regulators (pdf, 640 kB)||Application Notes|
AN-931: Understanding PulSAR ADC Support Circuitry
(pdf, 299 kB)
This application note discusses in general the pitfalls that occur regularly when using SAR ADCs and, more importantly, how to easily prevent them.
|AN-932: Power Supply Sequencing (pdf, 95 kB)||Application Notes|
|AN-935: Designing an ADC Transformer-Coupled Front End (pdf, 363 kB)||Application Notes|
|CN-0225: High Impedance, High CMR, ±10 V Analog Front End Signal Conditioner for Industrial Process Control and Automation (pdf, 640 kB)||Circuit Note|
|MT-074: Differential Drivers for Precision ADCs (pdf, 249 kB)||Tutorials|
|UG-340: Evaluation Board for the 10-Lead Family 14-/16-/18-Bit PulSAR ADCs (pdf, 4636 kB)||User Guides|
|MS-2210: Designing Power Supplies for High Speed ADC (pdf, 327 kB)||Technical Articles|
|MS-2022: Seven Steps to Successful Analog-to-Digital Signal Conversion (Noise Calculation for Proper Signal Conditioning) (pdf, 277 kB)||Technical Articles|
|MS-2124: Understanding AC Behaviors of High Speed ADCs (pdf, 276 kB)||Technical Articles|
Nine Often Overlooked ADC Specifications
(pdf, 445 kB)
Analog-to-digital converters (ADCs) have many specifications; some are more important for a given application than others. Understanding these specifications and controlling external devices affecting the ADC will lead to better performance.
High Speed Op Amp Drives a 16-Bit, 1-MSPS Differential-Input A/D Converter
(Analog Dialogue, Vol. 36, No. 6, November/December 2002)
Low-Power Data Conversion Technology Enhances Portability
Lowest-Power 16-Bit ADC Optimizes Portable Designs
|When high performance and low power make the design, ADI converters make the difference.||Overview||HTML|
8- to 18-Bit SAR ADCs ... From the Leader in High Performance Analog
(pdf, 1885 kB)
8- to 18-Bit SAR ADCs with Sample Rates up to 3 MSPS -- The latest additions to ADI’s ADC portfolio offer unrivaled functionality in terms of channel count and power supply voltage, optimal power/speed ratios, and the smallest packages to meet the demands of any data acquisition application, including portable, industrial, medical, wireless, and communications.
High Speed, High Accuracy 14-Bit, 16-Bit, and 18-Bit PulSAR ADCs
(pdf, 3826 kB)
A PulSAR Family Brochure (6/2006)
|RAQs index||Rarely Asked Questions||HTML|
|Glossary of EE Terms||Glossary||HTML|
|Title||Content Type||File Type|
|AD7685 IBIS Models||IBIS Models||HTML|
|BeMicro FPGA Project for AD7687 with Nios driver||FPGA HDL||HTML|
|AD7687 FMC-SDP Interposer & Evaluation Board / Xilinx KC705 Reference Design||FPGA HDL||HTML|
Were these recommendations helpful?
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.