SBAS547D May   2013  – August 2015 ADS8881

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Companion Products
  6. 6 Device Comparison
  7. 7 Pin Configurations and Functions
  8. 8 Specifications
    1. 8.1 Absolute Maximum Ratings
    2. 8.2 ESD Ratings
    3. 8.3 Recommended Operating Conditions
    4. 8.4 Thermal Information
    5. 8.5 Electrical Characteristics
    6. 8.6 Timing Requirements: 3-Wire Operation
    7. 8.7 Timing Requirements: 4-Wire Operation
    8. 8.8 Timing Requirements: Daisy-Chain
    9. 8.9 Typical Characteristics
  9. 9 Parametric Measurement Information
    1. 9.1 Equivalent Circuits
  10. 10Detailed Description
    1. 10.1 Overview
    2. 10.2 Functional Block Diagram
    3. 10.3 Feature Description
      1. 10.3.1 Analog Input
      2. 10.3.2 Reference
      3. 10.3.3 Clock
      4. 10.3.4 ADC Transfer Function
    4. 10.4 Device Functional Modes
      1. 10.4.1 CS Mode
        1. 10.4.1.1 3-Wire CS Mode Without a Busy Indicator
        2. 10.4.1.2 3-Wire CS Mode With a Busy Indicator
        3. 10.4.1.3 4-Wire CS Mode Without a Busy Indicator
        4. 10.4.1.4 4-Wire CS Mode With a Busy Indicator
      2. 10.4.2 Daisy-Chain Mode
        1. 10.4.2.1 Daisy-Chain Mode Without a Busy Indicator
        2. 10.4.2.2 Daisy-Chain Mode With a Busy Indicator
  11. 11Application and Implementation
    1. 11.1 Application Information
      1. 11.1.1 ADC Reference Driver
      2. 11.1.2 ADC Input Driver
        1. 11.1.2.1 Input Amplifier Selection
        2. 11.1.2.2 Antialiasing Filter
    2. 11.2 Typical Applications
      1. 11.2.1 DAQ Circuit for a 1-µs, Full-Scale Step Response
        1. 11.2.1.1 Design Requirements
        2. 11.2.1.2 Detailed Design Procedure
        3. 11.2.1.3 Application Curve
      2. 11.2.2 Low-Power DAQ Circuit for Excellent Dynamic Performance at 1 MSPS
        1. 11.2.2.1 Design Requirements
        2. 11.2.2.2 Detailed Design Procedure
        3. 11.2.2.3 Application Curve
      3. 11.2.3 DAQ Circuit for Lowest Distortion and Noise Performance at 1 MSPS
        1. 11.2.3.1 Design Requirements
        2. 11.2.3.2 Detailed Design Procedure
        3. 11.2.3.3 Application Curve
      4. 11.2.4 Ultralow-Power DAQ Circuit at 10 kSPS
        1. 11.2.4.1 Design Requirements
        2. 11.2.4.2 Detailed Design Procedure
        3. 11.2.4.3 Application Curve
  12. 12Power-Supply Recommendations
    1. 12.1 Power-Supply Decoupling
    2. 12.2 Power Saving
  13. 13Layout
    1. 13.1 Layout Guidelines
    2. 13.2 Layout Example
  14. 14Device and Documentation Support
    1. 14.1 Device Support
      1. 14.1.1 Development Support
    2. 14.2 Documentation Support
      1. 14.2.1 Related Documentation
    3. 14.3 Receiving Notification of Documentation Updates
    4. 14.4 Community Resources
    5. 14.5 Trademarks
    6. 14.6 Electrostatic Discharge Caution
    7. 14.7 Glossary
  15. 15Mechanical, Packaging, and Orderable Information

1 Features

  • Sample Rate: 1 MHz
  • No Latency Output
  • Unipolar, True-Differential Input Range:
    –VREF to +VREF
  • Wide Common-Mode Voltage Range:
    0 V to VREF with 90-dB CMRR (min)
  • SPI™-Compatible Serial Interface with
    Daisy-Chain Option
  • Excellent AC and DC Performance:
    • ADS8881C:
      INL: ±1 LSB (typ), ±2.0 LSB (max)
      DNL: ±1.0 LSB (max), 18-Bit NMC
      SNR: 100 dB, THD: –115 dB
    • ADS8881I:
      INL: ±1.5 LSB (typ), ±3.0 LSB (max)
      DNL: +1.5 and –1 LSB (max), 18-Bit NMC
      SNR: 100 dB, THD: –115 dB
  • Wide Operating Range:
    • AVDD: 2.7 V to 3.6 V
    • DVDD: 2.7 V to 3.6 V
      (Independent of AVDD)
    • REF: 2.5 V to 5 V (Independent of AVDD)
    • Operating Temperature:
      ADS8881C : 0°C to +70°C
      ADS8881I :       –40°C to +85°C
  • Low-Power Dissipation:
    • 5.5 mW at 1 MSPS
    • 0.55 mW at 100 kSPS
    • 55 µW at 10 kSPS
  • Power-Down Current (AVDD): 50 nA
  • Full-Scale Step Settling to 18 Bits: 290 ns
  • Packages: MSOP-10 and VSON-10

2 Applications

  • Automatic Test Equipment (ATE)
  • Instrumentation and Process Controls
  • Precision Medical Equipment
  • Low-Power, Battery-Operated Instruments

3 Description

The ADS8881 is an 18-bit, 1-MSPS, true-differential input, analog-to-digital converter (ADC). The device operates with a 2.5-V to 5-V external reference, offering a wide selection of signal ranges without additional input signal scaling. The reference voltage setting is independent of, and can exceed, the analog supply voltage (AVDD).

The device offers an SPI-compatible serial interface that also supports daisy-chain operation for cascading multiple devices. An optional busy-indicator bit makes synchronizing with the digital host easy.

The device supports unipolar, true-differential analog input signals with a differential input swing of –VREF to VREF. This true-differential analog input structure allows for a common-mode voltage of any value in the range of 0 V to VREF (when both inputs are within the operating input range of –0.1 V to VREF
+ 0.1 V).

Device operation is optimized for very low-power operation. Power consumption directly scales with speed. This feature makes the ADS8881 excellent for lower-speed applications.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
ADS8881x VSSOP (10) 3.00 mm × 3.00 mm
VSON (10) 3.00 mm × 3.00 mm
  1. For all available packages, see the orderable addendum at the end of the datasheet.

True-Differential Input Range

ADS8881 fbd_8881_sbas557.gif