The AD7690 is an 18-bit, successive approximation, analog-to-digital converter (ADC) that operates from a single power supply, VDD. It contains a low power, high speed, 18-bit sampling ADC with no missing codes, an internal conversion clock, and a versatile serial interface port. On the CNV rising edge, it samples the voltage difference between the IN+ and IN− pins. The voltages on these pins swing in opposite phase between 0 V and REF. The reference voltage, REF, is applied externally and can be set up to the supply voltage.
The power of the AD7690 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 the separate VIO supply.
The AD7690 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|
|AD7690: 18-Bit, 1.5 LSB INL, 400 kSPS PulSAR® Differential ADC in MSOP/QFN Data Sheet (Rev B, 07/2011) (pdf, 736 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|
|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|
|Front-End Amplifier and RC Filter Design for a Precision SAR Analog-to-Digital Converter||Technical Articles||HTML|
|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.
Voltage Reference Design for Precision Successive-Approximation ADCs
(Analog Dialogue, Volume 47 – June 2013)
18-bit ADC Features MSOP Package
(Portable Design, 10/31/2005)
Analog Claims 18-bit ADCs Are the Smallest
18-bit A/D Packs Speed & Precision into MSOP
Dimensions in Data Conversion: An Evolving Story
(Electronic Products, April 2006)
|When high performance and low power make the design, ADI converters make the difference.||Overview||HTML|
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 AD7690 with Nios driver||FPGA HDL||HTML|
|AD7690 FMC-SDP Interposer & Evaluation Board / Xilinx KC705 Reference Design||FPGA HDL||HTML|
Recommended Digital Isolators for the AD7690
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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.