AD7685:  16-Bit, 250 kSPS PulSAR® ADC in MSOP/QFN

The AD7685 is a 16-bit, charge redistribution successive approximation, analog-to-digital converter (ADC) that operates from a single power supply, VDD, between 2.3 V to 5.5 V. It contains a low ...More

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AD7685:  16-Bit, 250 kSPS PulSAR® ADC in MSOP/QFN

Product Description

The AD7685 is a 16-bit, charge redistribution successive approximation, analog-to-digital converter (ADC) that operates from a single power supply, VDD, between 2.3 V to 5.5 V. It contains a low power, high speed, 16-bit sampling ADC with no missing codes, an internal conversion clock, and a versatile serial interface port. The part also contains a low noise, wide bandwidth, short aperture delay, track-and-hold circuit. On the CNV rising edge, it samples an analog input IN+ between 0 V to REF with respect to a ground sense IN−. The reference voltage, REF, is applied externally and can be set up to the supply voltage.

Power dissipation scales linearly with 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 or provides an optional BUSY indicator. It is compatible with 1.8 V, 2.5 V, 3 V, or 5 V logic using the separate supply VIO.

The AD7685 is housed in a 10-lead MSOP or a 10-lead QFN (LFCSP) with operation specified from −40°C to +85°C.

Applications

  • Battery-powered equipment
  • Medical instruments
  • Mobile communications
  • Personal digital assistants (PDAs)
  • Data acquisition
  • Instrumentation
  • Process controls

    • Data Sheet, Rev. B, 3/07

    Features

    • 16-bit resolution with no missing codes
    • Throughput: 250 kSPS
    • INL: ±0.6 LSB typical, ±2 LSB maximum (±0.003% of FSR)
    • SINAD: 93.5 dB @ 20 kHz
    • THD: −110 dB @ 20 kHz
    • Pseudo differential analog input range 0 V to VREF with VREF up to VDD
    • No pipeline delay
    • Single-supply operation 2.3 V to 5.5 V with 1.8 V to 5 V logic interface
    • Serial interface SPI®-/QSPI™-/MICROWIRE™-/DSP-compatible
    • Daisy-chain multiple ADCs, BUSY indicator
    • Power dissipation
      1.4 μW @ 2.5 V/100 SPS
      1.35 mW @ 2.5 V/100 kSPS, 4 mW @ 5 V/100 kSPS
    • Standby current: 1 nA

    Diagrams

    AD7685 Diagram
    Functional Block Diagram for AD7685

    Specifications

    Resolution (Bits) 16bit
    T-Put Rate 250kSPS
    # Chan 1
    Supply V Single(+2.3 to +5.5),Single(+2.5),Single(+3),Single(+3.3),Single(+5)
    Pwr Diss n/a
    Interface Ser,SPI
    Ain Range (Vref) p-p
    SNR (dB) 93.5dB
    Pkg Type CSP,SOP

    AD7357 - Differential Input, Dual, Simultaneous Sampling, 4.25 MSPS, 14-Bit, SAR ADC

    AD7949 - 14-Bit, 8-Channel, 250 kSPS PulSAR® ADC

    AD7781 - 20-Bit, Pin-Programmable, Ultralow Power Sigma-Delta ADC

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

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    Part# Bits Throughput Rate # of Inputs Operating Pwr Diss
    AD9261 16 160MSPS 1 473mW
    AD9261-10 16 160MSPS 1 473mW
    AD9460-105 16 105MSPS 1 2.2W
    AD9460-80 16 80MSPS 1 1.8W
    AD9461 16 130MSPS 1 2.4W
    AD7610 16 250KSPS 1 110mW
    AD7612 16 750KSPS 1 230mW
    AD7621 16 3MSPS 1 86mW
    AD7622 16 2MSPS 1 85mW
    AD7623 16 1.33MSPS 1 55mW
    AD7650 16 570KSPS 1 115mW
    AD7652 16 500KSPS 1 90mW
    AD7653 16 1MSPS 1 145mW
    AD9446-100 16 100MSPS 1 2.8W
    AD9446-80 16 80MSPS 1 2.6W
    AD7983 16 1.33MSPS 1 12mW
    AD7400 16 10MSPS 1 90mW
    AD7663 16 250KSPS 1 41mW
    AD7664 16 570KSPS 1 115mW
    AD7665 16 570KSPS 1 107mW
    AD7666 16 500KSPS 1 90mW
    AD7667 16 1MSPS 1 145mW
    AD7671 16 1MSPS 1 125mW
    AD7400A 16 10MSPS 1 95mW
    AD7676 16 500KSPS 1 74mW
    AD7677 16 1MSPS 1 130mW
    AD7401 16 20MSPS 1 100mW
    AD7401A 16 20MSPS 1 105mW
    AD7685 16 250KSPS 1 -
    AD7686 16 500KSPS 1 21.5mW
    AD7687 16 250KSPS 1 12.5mW
    AD7688 16 500KSPS 1 21.5mW
    AD9260 16 2.5MSPS 1 637mW
    AD7693 16 500KSPS 1 21.5mW
    AD7694 16 250KSPS 1 6.3mW
    AD7720 16 12.5MSPS 1 215mW
    AD7721 16 468.75KSPS 1 150mW
    AD7723 16 1.2MSPS 1 475mW
    AD7725 16 900KSPS 1 615mW
    AD7980 16 1MSPS 1 10mW
    Pricing, Packaging & Availability

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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.
    **Sample availability may be better than production availability. Please enter samples into your cart to check sample availability.

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