Dual, 7th-Order, Sigma-Delta Modulator
The AD7724 is a dual 7th-order, sigma-delta modulator - it's dual version of the AD7720. Its SNR performance is 90 dB over a 90 kHz bandwidth. The part operates from a 5 V supply and accepts a differential input range of 0 V to 2.5 V or ±1.25 V centered about a common-mode bias. The analog inputs are continuously sampled by the analog modulators, eliminating the need for external sample and hold circuitry. The input information is contained in the output stream as a density of ones. The original information can be reconstructed with an appropriate digital filter.
The part provides an accurate on-chip 2.5 V reference. A reference input/output function is provided to allow either the internal reference or an external system reference to be used as the reference source for the part.
The part is offered in a 48-pin TQFP package and is designed to operate from –40°C to 85°C.
Typically, the AD7724 is followed by a digital filter to achieve a parallel A/D result, which is just like our standard sigma-delta A/Ds. Having a separate filter allows users to customize their filter respose, which can be done with one of our own DSPs or with a gate array.
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.
MS-2210: Designing Power Supplies for High Speed ADC
Delta-Sigma Rocks RF, As ADC Designers Jump On Jitter
(Electronic Design, 1/12/06)
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.
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.