AD7724 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.

Features and Benefits
  • 13 MHz Master Clock Frequency
  • 0 V to +2.5 V or ±1.25 V Input Range
  • Single Bit Output Stream
  • 90 dB Dynamic Range
  • Logic Outputs 3 V/5 V Compatible
  • Power Supplies
    - AVDD, DVDD: 5 V ± 5%
    - DVDD1: 3 V ± 5%
  • On-Chip 2.5 V Voltage Reference
  • 48-Lead LQFP
Analog to Digital Converters
Data Sheets
Documentnote
AD7724: Dual CMOS Sigma-Delta Modulators Data Sheet (Rev. B)PDF 288 kB
Application Notes
Documentnote
AN-202: An IC Amplifier User’s Guide to Decoupling, Grounding, and Making Things Go Right for a Change (Rev. B)PDF 76.97 K
AN-389: Using Sigma-Delta Converters-Part 2PDF 590 kB
AN-388: Using Sigma-Delta Converters-Part 1PDF 590 kB
AN-311: How to Reliably Protect CMOS Circuits Against Power Supply OvervoltagingPDF 217 kB
AN-397: Electrically Induced Damage to Standard Linear Integrated Circuits:PDF 149 kB
AN-283: Sigma-Delta ADCs and DACsPDF 1699 kB
Order Information
Part NumberPackagePacking QtyTemp RangePrice 100-499Price 1000+RoHS
AD7724ASTZ Production48 ld LQFPOTH 250-40 to 85C11.910.12Y
AD7724ASTZ-REEL Production48 ld LQFPREEL 2000-40 to 85C010.12Y
Reference Materials
AD7724: Dual CMOS Sigma-Delta Modulators Data Sheet (Rev. B) ad7724
AN-202: An IC Amplifier User’s Guide to Decoupling, Grounding, and Making Things Go Right for a Change (Rev. B) ad7715
AN-389: Using Sigma-Delta Converters-Part 2 ad7715
AN-388: Using Sigma-Delta Converters-Part 1 ad7715
AN-397: 标准线性集成电路的电诱发损坏 (Rev. 0) ad7715
AN-202: IC放大器用户指南:去耦、接地及其他一些要点 (Rev. 0) ad8021
AN-311: How to Reliably Protect CMOS Circuits Against Power Supply Overvoltaging ad1674
AN-397: Electrically Induced Damage to Standard Linear Integrated Circuits: ad7715
AN-311: 如何切实有效地保护CMOS电路不受电源过压影响 (Rev. 0) adg406
AN-389: 使用Σ-Δ转换器—第二部分[中文版] (Rev. 0) ad7715
AN-388: 使用Σ-Δ转换器—第一部分[中文版] (Rev. 0) ad7715
AN-283: Σ-Δ型ADC和DAC[中文版] (Rev. 0) ad74111
AN-283: Sigma-Delta ADCs and DACs ad7715
MS-2210:高速ADC的电源设计 ad9861
Part 2: Circuit Suggestions Using Features and Functionality of New Sigma-Delta ad7715
Part 1: Circuit Suggestions Using Features and Functionality of New Sigma-Delta ad7715