SBAS779 December 2016 ADS8671 , ADS8675

PRODUCTION DATA. 

  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Pin Configuration and Functions
  6. Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Timing Requirements: Conversion Cycle
    7. 6.7 Timing Requirements: Asynchronous Reset
    8. 6.8 Timing Requirements: SPI-Compatible Serial Interface
    9. 6.9 Timing Requirements: Source-Synchronous Serial Interface (External Clock)
    10. 6.10Timing Requirements: Source-Synchronous Serial Interface (Internal Clock)
    11. 6.11Typical Characteristics
  7. Detailed Description
    1. 7.1Overview
    2. 7.2Functional Block Diagram
    3. 7.3Feature Description
      1. 7.3.1Analog Input Structure
      2. 7.3.2Analog Input Impedance
      3. 7.3.3Input Protection Circuit
      4. 7.3.4Programmable Gain Amplifier (PGA)
      5. 7.3.5Second-Order, Low-Pass Filter (LPF)
      6. 7.3.6ADC Driver
      7. 7.3.7Reference
        1. 7.3.7.1Internal Reference
        2. 7.3.7.2External Reference
      8. 7.3.8ADC Transfer Function
      9. 7.3.9Alarm Features
        1. 7.3.9.1Input Alarm
        2. 7.3.9.2AVDD Alarm
    4. 7.4Device Functional Modes
      1. 7.4.1Host-to-Device Connection Topologies
        1. 7.4.1.1Single Device: All multiSPI Options
        2. 7.4.1.2Single Device: Standard SPI Interface
        3. 7.4.1.3Multiple Devices: Daisy-Chain Topology
      2. 7.4.2Device Operational Modes
        1. 7.4.2.1RESET State
        2. 7.4.2.2ACQ State
        3. 7.4.2.3CONV State
    5. 7.5Programming
      1. 7.5.1Data Transfer Frame
      2. 7.5.2Input Command Word and Register Write Operation
      3. 7.5.3Output Data Word
      4. 7.5.4Data Transfer Protocols
        1. 7.5.4.1Protocols for Configuring the Device
        2. 7.5.4.2Protocols for Reading From the Device
          1. 7.5.4.2.1Legacy, SPI-Compatible (SYS-xy-S) Protocols with a Single SDO-x
          2. 7.5.4.2.2Legacy, SPI-Compatible (SYS-xy-S) Protocols with Dual SDO-x
          3. 7.5.4.2.3Source-Synchronous (SRC) Protocols
            1. 7.5.4.2.3.1Output Clock Source Options
            2. 7.5.4.2.3.2Output Bus Width Options
    6. 7.6Register Maps
      1. 7.6.1Device Configuration and Register Maps
        1. 7.6.1.1DEVICE_ID_REG Register (address = 00h)
        2. 7.6.1.2RST_PWRCTL_REG Register (address = 04h)
        3. 7.6.1.3SDI_CTL_REG Register (address = 08h)
        4. 7.6.1.4SDO_CTL_REG Register (address = 0Ch)
        5. 7.6.1.5DATAOUT_CTL_REG Register (address = 10h)
        6. 7.6.1.6RANGE_SEL_REG Register (address = 14h)
        7. 7.6.1.7ALARM_REG Register (address = 20h)
        8. 7.6.1.8ALARM_H_TH_REG Register (address = 24h)
        9. 7.6.1.9ALARM_L_TH_REG Register (address = 28h)
  8. Application and Implementation
    1. 8.1Application Information
    2. 8.2Typical Application
      1. 8.2.1Design Requirements
      2. 8.2.2Detailed Design Procedure
      3. 8.2.3Application Curves
  9. Power Supply Recommendations
    1. 9.1Power Supply Decoupling
    2. 9.2Power Saving
      1. 9.2.1NAP Mode
      2. 9.2.2Power-Down (PD) Mode
  10. 10Layout
    1. 10.1Layout Guidelines
    2. 10.2Layout Example
  11. 11Device and Documentation Support
    1. 11.1Documentation Support
      1. 11.1.1Related Documentation
    2. 11.2Related Links
    3. 11.3Receiving Notification of Documentation Updates
    4. 11.4Community Resources
    5. 11.5Trademarks
    6. 11.6Electrostatic Discharge Caution
    7. 11.7Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Orderable Information

Features

  • 14-Bit ADC with Integrated Analog Front-End
  • High Speed:
    • ADS8671: 1 MSPS
    • ADS8675: 500 kSPS
  • Software Programmable Input Ranges:
    • Bipolar Ranges: ±12.288 V, ±10.24 V, ±6.144 V, ±5.12 V, and ±2.56 V
    • Unipolar Ranges: 0 V–12.288 V, 0 V–10.24 V, 0 V–6.144 V, and 0 V–5.12 V
  • 5-V Analog Supply: 1.65-V to 5-V I/O Supply
  • Constant Resistive Input Impedance ≥ 1 MΩ
  • Input Overvoltage Protection: Up to ±20 V
  • On-Chip, 4.096-V Reference with Low Drift
  • Excellent Performance:
    • DNL: ±0.25 LSB; INL: ±0.4 LSB
    • SNR: 84.5 dB; THD: –105 dB
  • ALARM → High, Low Thresholds per Channel
  • multiSPI™ Interface with Daisy-Chain
  • Extended Industrial Temperature Range:
    –40°C to +125°C

Applications

  • Channel-Isolated PLC Analog Input Modules
  • Test and Measurement
  • Battery Pack Monitoring

Description

The ADS8671 and ADS8675 devices belong to a family of integrated data acquisition system based on a successive approximation (SAR) analog-to-digital converter (ADC). The devices feature a high-speed, high-precision SAR ADC, integrated analog front-end (AFE) input driver circuit, overvoltage protection circuit up to ±20 V, and an on-chip 4.096-V reference with extremely low temperature drift.

The devices operate on a single 5-V analog supply, but support true bipolar input ranges of ±12.288 V, ±6.144 V, ±10.24 V, ±5.12 V, and ±2.56 V, as well as unipolar input ranges of 0 V to 12.288 V, 0 V to 10.24 V, 0 V to 6.144 V, and 0 V to 5.12 V. The gain and offset errors are accurately trimmed within the specified values for each input range to ensure high dc precision. The input range selection is done by software programming of the device internal registers. The devices offer a high resistive input impedance (≥ 1 MΩ) irrespective of the selected input range.

The multiSPI digital interface is backward-compatible to the traditional SPI protocol. Additionally, configurable features simplify interface to a wide range of host controllers.

Device Information(1)

PART NUMBERPACKAGEBODY SIZE (NOM)
ADS867xTSSOP (16)5.00 mm × 4.40 mm
WQFN (16)4.00 mm × 4.00 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

Block Diagram

ADS8671 ADS8675 frontpage_14bit_sbas779.gif