SBAS817D November   2017  – June 2024 ADS8166 , ADS8167 , ADS8168

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Thermal Information
    4. 5.4 Recommended Operating Conditions
    5. 5.5 Electrical Characteristics
    6. 5.6 Timing Requirements
    7. 5.7 Switching Characteristics
    8. 5.8 Timing Diagrams
    9. 5.9 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Analog Multiplexer
        1. 6.3.1.1 Multiplexer Configurations
        2. 6.3.1.2 Multiplexer With Minimum Crosstalk
        3. 6.3.1.3 Early Switching for Direct Sensor Interface
      2. 6.3.2 Reference
      3. 6.3.3 REFby2 Buffer
      4. 6.3.4 Converter Module
        1. 6.3.4.1 Internal Oscillator
        2. 6.3.4.2 ADC Transfer Function
      5. 6.3.5 Low-Dropout Regulator (LDO)
    4. 6.4 Device Functional Modes
      1. 6.4.1 Channel Selection Using Internal Multiplexer
        1. 6.4.1.1 Manual Mode
        2. 6.4.1.2 On-The-Fly Mode
        3. 6.4.1.3 Auto Sequence Mode
        4. 6.4.1.4 Custom Channel Sequencing Mode
      2. 6.4.2 Digital Window Comparator
    5. 6.5 Programming
      1. 6.5.1 Data Transfer Protocols
        1. 6.5.1.1 Enhanced-SPI Interface
          1. 6.5.1.1.1 Protocols for Configuring the Device
          2. 6.5.1.1.2 Protocols for Reading From the Device
            1. 6.5.1.1.2.1 SPI Protocols With a Single SDO
            2. 6.5.1.1.2.2 SPI Protocols With Dual SDO
            3. 6.5.1.1.2.3 Clock Re-Timer Data Transfer
              1. 6.5.1.1.2.3.1 Output Bus Width Options
      2. 6.5.2 Register Read/Write Operation
  8. 7 Register Maps
    1. 7.1 Interface and Hardware Configuration Registers
      1. 7.1.1 REG_ACCESS Register (address = 00h) [reset = 00h]
      2. 7.1.2 PD_CNTL Register (address = 04h) [reset = 00h]
      3. 7.1.3 SDI_CNTL Register (address = 008h) [reset = 00h]
      4. 7.1.4 SDO_CNTL1 Register (address = 0Ch) [reset = 00h]
      5. 7.1.5 SDO_CNTL2 Register (address = 0Dh) [reset = 00h]
      6. 7.1.6 SDO_CNTL3 Register (address = 0Eh) [reset = 00h]
      7. 7.1.7 SDO_CNTL4 Register (address = 0Fh) [reset = 00h]
      8. 7.1.8 DATA_CNTL Register (address = 10h) [reset = 00h]
      9. 7.1.9 PARITY_CNTL Register (address = 11h) [reset = 00h]
    2. 7.2 Device Calibration Registers
      1. 7.2.1 OFST_CAL Register (address = 18h) [reset = 00h]
      2. 7.2.2 REF_MRG1 Register (address = 19h) [reset = 00h]
      3. 7.2.3 REF_MRG2 Register (address = 1Ah) [reset = 00h]
      4. 7.2.4 REFby2_MRG Register (address = 1Bh) [reset = 00h]
    3. 7.3 Analog Input Configuration Registers
      1. 7.3.1 AIN_CFG Register (address = 24h) [reset = 00h]
      2. 7.3.2 COM_CFG Register (address = 27h) [reset = 00h]
    4. 7.4 Channel Sequence Configuration Registers Map
      1. 7.4.1 DEVICE_CFG Register (address = 1Ch) [reset = 00h]
      2. 7.4.2 CHANNEL_ID Register (address = 1Dh) [reset = 00h]
      3. 7.4.3 SEQ_START Register (address = 1Eh) [reset = 00h]
      4. 7.4.4 SEQ_ABORT Register (address = 1Fh) [reset = 00h]
      5. 7.4.5 ON_THE_FLY_CFG Register (address = 2Ah) [reset = 00h]
      6. 7.4.6 AUTO_SEQ_CFG1 Register (address = 80h) [reset = 00h]
      7. 7.4.7 AUTO_SEQ_CFG2 Register (address = 82h) [reset = 00h]
      8. 7.4.8 Custom Channel Sequencing Mode Registers
        1. 7.4.8.1 CCS_START_INDEX Register (address = 88h) [reset = 00h]
        2. 7.4.8.2 CCS_END_INDEX Register (address = 89h) [reset = 00h]
        3. 7.4.8.3 CCS_SEQ_LOOP Register (address = 8Ah) [reset = 00h]
        4. 7.4.8.4 CCS_CHID_INDEX_m Registers (address = 8C, 8E, 90, 92, 94, 96, 98, 9A, 9C, 9E, A0, A2, A4, A6, A8, and AAh) [reset = 00h]
        5. 7.4.8.5 REPEAT_INDEX_m Registers (address = 8D, 8F, 91, 93, 95, 97, 99, 9B, 9D, 9F, A1, A3, A5, A7, A9, and ABh) [reset = 00h]
    5. 7.5 Digital Window Comparator Configuration Registers Map
      1. 7.5.1  ALERT_CFG Register (address = 2Eh) [reset = 00h]
      2. 7.5.2  HI_TRIG_AINx[15:0] Register (address = 4Dh to 30h) [reset = 0000h]
      3. 7.5.3  LO_TRIG_AINx[15:0] Register (address = 71h to 54h) [reset = 0000h]
      4. 7.5.4  HYSTERESIS_AINx[7:0] Register (address = 4Fh to 33h) [reset = 00h]
      5. 7.5.5  ALERT_LO_STATUS Register (address = 78h) [reset = 00h]
      6. 7.5.6  ALERT_HI_STATUS Register (address = 79h) [reset = 00h]
      7. 7.5.7  ALERT_STATUS Register (address = 7Ah) [reset = 00h]
      8. 7.5.8  CURR_ALERT_LO_STATUS Register (address = 7Ch) [reset = 00h]
      9. 7.5.9  CURR_ALERT_HI_STATUS Register (address = 7Dh) [reset = 00h]
      10. 7.5.10 CURR_ALERT_STATUS Register (address = 7Eh) [reset = 00h]
  9. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Multiplexer Input Connection
    2. 8.2 Typical Applications
      1. 8.2.1 1MSPS DAQ Circuit With Lowest Distortion and Noise Performance
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
        3. 8.2.1.3 Application Curve
    3.     Power Supply Recommendations
    4. 8.3 Layout
      1. 8.3.1 Layout Guidelines
        1. 8.3.1.1 Analog Signal Path
        2. 8.3.1.2 Grounding and PCB Stack-Up
        3. 8.3.1.3 Decoupling of Power Supplies
        4. 8.3.1.4 Reference Decoupling
        5. 8.3.1.5 Reference Buffer Decoupling
        6. 8.3.1.6 Multiplexer Input Decoupling
        7. 8.3.1.7 ADC Input Decoupling
        8. 8.3.1.8 Example Schematic
      2. 8.3.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Documentation Support
      1. 9.1.1 Related Documentation
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

6.3.2 Reference

The ADS816x has a precision, low-drift reference internal to the device. The device features an internal reference source with a nominal output value of 4.096V. On power-up, the internal reference is enabled by default. Place a minimum 1µF decoupling capacitor, as illustrated in Figure 6-6, between the REFIO and REFM pins.

Figure 6-7 shows the connections for using the device with an external reference. Use a reference without a low-impedance output buffer because the input leakage current of the internal reference buffer is less than 1μA.

For the minimum ADC input offset error (VOS), set the REF_SEL[2:0] bits to the value closest to VREF (see the OFST_CAL register). Set the REF_OFST[4:0] (see the REF_MRG1 register) bits to add or subtract an intentional offset voltage as described in Table 7-14. Short the two REFP pins externally. Short the REFM pin to GND externally. Place a decoupling capacitor CREFP between the REFP and the REFM pins as close to the device as possible; see the Layout section for layout recommendations.

ADS8166 ADS8167 ADS8168 Internal ReferenceFigure 6-6 Internal Reference
ADS8166 ADS8167 ADS8168 External ReferenceFigure 6-7 External Reference