SBAS430F January   2009  – April 2018 DAC7568 , DAC8168 , DAC8568

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Block Diagram
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 Electrical Characteristics
    3. 7.3 Timing Requirements
    4. 7.4 Typical Characteristics: Internal Reference
    5. 7.5 Typical Characteristics: DAC at AVDD = 5.5 V
    6. 7.6 Typical Characteristics: DAC at AVDD = 3.6 V
    7. 7.7 Typical Characteristics: DAC at AVDD = 2.7 V
  8. 8 Detailed Description
    1. 8.1 Functional Block Diagram
    2. 8.2 Feature Description
      1. 8.2.1  Digital-to-Analog Converter (DAC)
      2. 8.2.2  Resistor String
      3. 8.2.3  Output Amplifier
      4. 8.2.4  Internal Reference
      5. 8.2.5  Serial Interface
      6. 8.2.6  Input Shift Register
        1. Table 1. DAC8568 Data Input Register Format
        2. Table 2. DAC8168 Data Input Register Format
        3. Table 3. DAC7568 Data Input Register Format
      7. 8.2.7  SYNC Interrupt
      8. 8.2.8  Power-on Reset to Zero Scale or Midscale
      9. 8.2.9  Clear Code Register and CLR Pin
      10. 8.2.10 Software Reset Function
      11. 8.2.11 Operating Examples: DAC7568/DAC8168/DAC8568
        1. Table 4.   1st: Write to Data Buffer A:
        2. Table 5.   2nd: Write to Data Buffer B:
        3. Table 6.   3rd: Write to Data Buffer G:
        4. Table 7.   4th: Write to Data Buffer H and Simultaneously Update all DACs:
        5. Table 8.   1st: Write to Data Buffer C and Load DAC C: DAC C Output Settles to Specified Value Upon Completion:
        6. Table 9.   2nd: Write to Data Buffer D and Load DAC D: DAC D Output Settles to Specified Value Upon Completion:
        7. Table 10. 3rd: Write to Data Buffer E and Load DAC E: DAC E Output Settles to Specified Value Upon Completion:
        8. Table 11. 4th: Write to Data Buffer F and Load DAC F: DAC F Output Settles to Specified Value Upon Completion:
        9. Table 12. 1st: Write Power-Down Command to DAC Channel A and DAC Channel B: DAC A and DAC B to 1kΩ.
        10. Table 13. 2nd: Write Power-Down Command to DAC Channel H: DAC H to 1kΩ.
        11. Table 14. 3rd: Write Power-Down Command to DAC Channel C and DAC Channel D: DAC C and DAC D to 100kΩ.
        12. Table 15. 4th: Write Power-Down Command to DAC Channel F: DAC F to 100kΩ.
        13. Table 16. 1st: Write Sequence for Enabling the DAC7568, DAC8168, and DAC8568 Internal Reference All the Time:
        14. Table 17. 2nd: Write Sequence to Power-Down All DACs to High-Impedance:
        15. Table 18. 1st: Write Sequence for Disabling the DAC7568, DAC8168, and DAC8568 Internal Reference All the Time (after this sequence, these devices require an external reference source to function):
        16. Table 19. 2nd: Write Sequence to Write Specified Data to All DACs:
    3. 8.3 Device Functional Modes
      1. 8.3.1 Enable/Disable Internal Reference
        1. 8.3.1.1 Static Mode
          1. Table 20. Write Sequence for Enabling Internal Reference (Static Mode) (Internal Reference Powered On—08000001h)
          2. Table 21. Write Sequence for Disabling Internal Reference (Static Mode) (Internal Reference Powered On—08000000h)
        2. 8.3.1.2 Flexible Mode
          1. Table 22. Write Sequence for Enabling Internal Reference (Flexible Mode) (Internal Reference Powered On—09080000h)
          2. Table 23. Write Sequence for Enabling Internal Reference (Flexible Mode) (Internal Reference Always Powered On—090A0000h)
          3. Table 24. Write Sequence for Disabling Internal Reference (Flexible Mode) (Internal Reference Always Powered Down—090C0000h)
          4. Table 25. Write Sequence for Switching from Flexible Mode to Static Mode for Internal Reference (Internal Reference Always Powered Down—09000000h)
      2. 8.3.2 LDAC Functionality
      3. 8.3.3 Power-Down Modes
        1. 8.3.3.1 DAC Power-Down Commands
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications - Microprocessor Interfacing
      1. 9.2.1 DAC7568/DAC8168/DAC8568 to an 8051 Interface
        1. 9.2.1.1 Detailed Design Procedure
          1. 9.2.1.1.1 Internal Reference
            1. 9.2.1.1.1.1 Supply Voltage
            2. 9.2.1.1.1.2 Temperature Drift
            3. 9.2.1.1.1.3 Noise Performance
            4. 9.2.1.1.1.4 Load Regulation
            5. 9.2.1.1.1.5 Long-Term Stability
            6. 9.2.1.1.1.6 Thermal Hysteresis
          2. 9.2.1.1.2 DAC Noise Performance
          3. 9.2.1.1.3 Bipolar Operation Using The DAC7568/DAC8168/DAC8568
      2. 9.2.2 DAC7568/DAC8168/DAC8568 to Microwire Interface
      3. 9.2.3 DAC7568/DAC8168/DAC8568 to 68HC11 Interface
  10. 10Layout
    1. 10.1 Layout Guidelines
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Device Nomenclature
        1. 11.1.1.1 Static Performance
          1. 11.1.1.1.1  Resolution
          2. 11.1.1.1.2  Least Significant Bit (LSB)
          3. 11.1.1.1.3  Most Significant Bit (MSB)
          4. 11.1.1.1.4  Relative Accuracy or Integral Nonlinearity (INL)
          5. 11.1.1.1.5  Differential Nonlinearity (DNL)
          6. 11.1.1.1.6  Full-Scale Error
          7. 11.1.1.1.7  Offset Error
          8. 11.1.1.1.8  Zero-Code Error
          9. 11.1.1.1.9  Gain Error
          10. 11.1.1.1.10 Full-Scale Error Drift
          11. 11.1.1.1.11 Offset Error Drift
          12. 11.1.1.1.12 Zero-Code Error Drift
          13. 11.1.1.1.13 Gain Temperature Coefficient
          14. 11.1.1.1.14 Power-Supply Rejection Ratio (PSRR)
          15. 11.1.1.1.15 Monotonicity
        2. 11.1.1.2 Dynamic Performance
          1. 11.1.1.2.1  Slew Rate
          2. 11.1.1.2.2  Output Voltage Settling Time
          3. 11.1.1.2.3  Code Change/Digital-to-Analog Glitch Energy
          4. 11.1.1.2.4  Digital Feedthrough
          5. 11.1.1.2.5  Channel-to-Channel DC Crosstalk
          6. 11.1.1.2.6  Channel-to-Channel AC Crosstalk
          7. 11.1.1.2.7  Signal-to-Noise Ratio (SNR)
          8. 11.1.1.2.8  Total Harmonic Distortion (THD)
          9. 11.1.1.2.9  Spurious-Free Dynamic Range (SFDR)
          10. 11.1.1.2.10 Signal-to-Noise plus Distortion (SINAD)
          11. 11.1.1.2.11 DAC Output Noise Density
          12. 11.1.1.2.12 DAC Output Noise
          13. 11.1.1.2.13 Full-Scale Range (FSR)
    2. 11.2 Related Links
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Community Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

8.3.1 Enable/Disable Internal Reference

The internal reference in the DAC7568, DAC8168, and DAC8568 is disabled by default for debugging, evaluation purposes, or when using an external reference. The internal reference can be powered up and powered down using a serial command that requires a 32-bit write sequence (see the Serial Interface section), as shown in Table 20 and Table 22. During the time that the internal reference is disabled, the DAC functions normally using an external reference. At this point, the internal reference is disconnected from the VREFIN/VREFOUT pin (3-state output). Do not attempt to drive the VREFIN/VREFOUT pin externally and internally at the same time indefinitely.

There are two modes that allow communication with the internal reference: Static and Flexible. In Flexible mode, DB19 must be set to '1'.