AD7765 24-Bit, 156 kSPS, 112 dB Sigma-Delta ADC with On-Chip Buffers and Serial Interface

The AD7765 is a high performance, 24-bit sigma-delta (Σ-Δ) analog-to-digital converter (ADC). It combines wide input bandwidth, high speed, and performance of 112 dB dynamic range at a 156 kHz output data rate. With excellent dc specifications, the converter is ideal for high speed data acquisition of ac signals where dc data is also required.

Using the AD7765 eases the front-end antialias filtering requirements, simplifying the design process significantly. The AD7765 offers pin-selectable decimation rates of 128× and 256×. Other features include an integrated buffer to drive the reference, as well as a fully differential amplifier to buffer and level shift the input to the modulator.

An overrange alert pin indicates when an input signal has exceeded the acceptable range. The addition of internal gain and internal overrange registers makes the AD7765 a compact, highly integrated data acquisition device requiring minimal peripheral components.

The AD7765 also offers a low power mode, significantly reducing power dissipation without reducing the output data rate or available input bandwidth.

The differential input is sampled at up to 40 MSPS by an analog modulator. The modulator output is processed by a series of low-pass filters. The external clock frequency applied to the AD7765 determines the sample rate, filter corner frequencies, and output word rate.

The AD7765 device boasts a full band on-board FIR filter. The full stop-band attenuation of the filter is achieved at the Nyquist frequency. This feature offers increased protection from signals that lie above the Nyquist frequency being aliased back into the input signal bandwidth.

The reference voltage supplied to the AD7765 determines the input range. With a 4 V reference, the analog input range is ±3.2768 V differential, biased around a common mode of 2.048 V. This common-mode biasing can be achieved using the on-chip differential amplifier, further reducing the external signal conditioning requirements.

The AD7765 is available in a 28-lead TSSOP package and is specified over the industrial temperature range of −40°C to +85°C.

Applications
  • Data acquisition systems
  • Vibration analysis
  • Instrumentation
Features and Benefits
  • High performance, 24-bit Σ-Δ ADC
  • 115 dB dynamic range at 78 kHz output
    data rate
  • 112 dB dynamic range at 156 kHz output
    data rate
  • 156 kHz maximum fully filtered output
    word rate
  • Pin-selectable oversampling rate
    (128× and 256×)
  • Low power mode
  • Flexible SPI
  • Please see data sheet for additional features.
  • Analog to Digital Converters
    Data Sheets
    Documentnote
    AD7765: 24-Bit, 156 kSPS, 112 dB Sigma-Delta ADC with On-Chip Buffers and Serial Interface Data Sheet (Rev. A)PDF 1039 kB
    Order Information
    Part NumberPackagePacking QtyTemp RangePrice 100-499Price 1000+RoHS
    AD7765BRUZ Production28 ld TSSOP (4.4mm)OTH 50-40 to 85C10.788.56Y
    AD7765BRUZ-REEL7 Production28 ld TSSOP (4.4mm)REEL 1000-40 to 85C08.56Y
    Evaluation Boards
    Part NumberDescriptionPriceRoHS
    EVAL-AD7764EDZEvaluation Board59Y
    EVAL-AD7765EDZEvaluation Board59Y
    EVAL-CED1ZEvaluation Board249Y
    Reference Materials
    AD7765: 24-Bit, 156 kSPS, 112 dB Sigma-Delta ADC with On-Chip Buffers and Serial Interface Data Sheet (Rev. A) ad7765
    CN-0157: 24-Bit, 4-Channel, High Dynamic Range, 156 kSPS per Channel... ad7765
    MS-2210:高速ADC的电源设计 ad9861