AD7780 24-Bit Pin-Programmable Low Power Σ−Δ ADC

The AD7780 is a complete low power front-end solution for bridge sensor products, including weigh scales, strain gages, and pressure sensors. It contains a precision, low power, 24-bit sigma-delta (Σ-Δ) ADC; an on-chip, low noise programmable gain amplifier (PGA); and an on-chip oscillator.

Consuming only 330 μA, the AD7780 is particularly suitable for portable or battery-operated products where very low power is required. The AD7780 also has a power-down mode that allows the user to switch off the power to the bridge sensor and power down the AD7780 when not converting, thus increasing the battery life of the product.

For ease of use, all the features of the AD7780 are controlled by dedicated pins. Each time a data read occurs, eight status bits are appended to the 24-bit conversion. These status bits contain a pattern sequence that can be used to confirm the validity of the serial transfer.

The on-chip PGA has a gain of 1 or 128, supporting a full-scale differential input of ±5 V or ±39 mV. The device has two filter response options. The filter response at the 16.7 Hz update rate provides superior dynamic performance. The settling time is 120 ms at this update rate. At the 10 Hz update rate, the filter response provides greater than −45 dB of stop-band attenuation. In load cell applications, this stop-band rejection is useful to reject low frequency mechanical vibrations of the load cell. The settling time is 300 ms at this update rate. Simultaneous 50 Hz/60 Hz rejection occurs at both the 10 Hz and 16.7 Hz update rates.

The AD7780 operates with a power supply from 2.7 V to 5.25 V. It is available in a narrow body, 14-lead SOIC package and a 16-lead TSSOP package.

Applications
  • Weigh scales
  • Pressure Measurement
  • Industrial Process Control
  • Portable instrumentation
Features and Benefits
  • Pin-programmable filter response
    Update rate: 10 Hz or 16.7 Hz
  • Pin-programmable in-amp gain
  • Pin-programmable power-down and reset
  • Status function
  • Internal clock oscillator
  • Internal bridge power-down switch
  • Current
    115 μA typical (gain = 1)
    330 μA typical (gain = 128)
  • Please see data sheet for additional features
  • Analog to Digital Converters
    Reference Designs
    Software & Systems Requirements
    Data Sheets
    Documentnote
    AD7780: 24-Bit, Pin-Programmable, Ultralow Power Sigma-Delta ADC Data Sheet (Rev. A)PDF 409 kB
    Application Notes
    Documentnote
    AN-1187: Radiated Immunity Performance of the AD7780 in Weigh Scale Applications (Rev. 0)
    AD7780 EMC Gerber File
    PDF 465 kB
    AN-968: Current Sources: Options and Circuits (Rev. 0)PDF 131 kB
    User Guides
    Documentnote
    UG-078: Evaluation Board for the AD7780 24-Bit, Pin-Programmable, Low Power, Sigma-Delta ADCPDF 651 kB
    Order Information
    Part NumberPackagePacking QtyTemp RangePrice 100-499Price 1000+RoHS
    AD7780BRUZ Production16 ld TSSOPOTH 96-40 to 105C4.653.95Y
    AD7780BRUZ-REEL Production16 ld TSSOPREEL 2500-40 to 105C03.95Y
    AD7780BRZ Production14 ld SOICOTH 56-40 to 105C4.653.95Y
    AD7780BRZ-REEL Last Time Buy14 ld SOICREEL 2500-40 to 105C03.95Y
    Evaluation Boards
    Part NumberDescriptionPriceRoHS
    EVAL-AD7780EBZEvaluation Board59Y
    Reference Materials
    AD7780: 24-Bit, Pin-Programmable, Ultralow Power Sigma-Delta ADC Data Sheet (Rev. A) ad7780
    CN0107 设计和集成文件 adp3303
    AD7780参考代码 ad7780
    AD7780 Evaluation Board Software ad7780
    AN-1187: Radiated Immunity Performance of the AD7780 in Weigh Scale Applications (Rev. 0) ad7780
    AN-1187: AD7780在电子秤应用中的辐射抗扰度性能 (Rev. 0) ad7780
    AD7780 EMC Gerber File ad7780
    AN-968: 电流源:方案与电路 (Rev. 0) ad7783
    AN-968: Current Sources: Options and Circuits (Rev. 0) ad7783
    UG-078: AD7780 24位、引脚可编程、低功耗、Σ-Δ型ADC评估板 ad7780
    UG-078: Evaluation Board for the AD7780 24-Bit, Pin-Programmable, Low Power, Sigma-Delta ADC ad7780
    高分辨率ADC—概览(媒体精选) ad7780
    Test & Instrumentation Solutions Bulletin, Volume 10, Issue 3 ad7780
    CN-0107: Weigh Scale Design Using the AD7780 24-Bit Sigma-Delta ADC with... ad7780
    MS-2210:高速ADC的电源设计 ad9861