SLASER3A July   2018  – November 2018 DAC61408 , DAC71408 , DAC81408

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Functional 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 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Timing Requirements
    7. 7.7 Typical Characteristics
  8. 8 Parameter Measurement Information
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Digital-to-Analog Converters (DACs) Architecture
        1. 9.3.1.1 DAC Transfer Function
        2. 9.3.1.2 DAC Register Structure
          1. 9.3.1.2.1 DAC Register Synchronous and Asynchronous Updates
          2. 9.3.1.2.2 Broadcast DAC Register
          3. 9.3.1.2.3 Clear DAC Operation
      2. 9.3.2 Internal Reference
      3. 9.3.3 Device Reset Options
        1. 9.3.3.1 Power-on-Reset (POR)
        2. 9.3.3.2 Hardware Reset
        3. 9.3.3.3 Software Reset
      4. 9.3.4 Thermal Protection
        1. 9.3.4.1 Analog Temperature Sensor: TEMPOUT Pin
        2. 9.3.4.2 Thermal Shutdown
    4. 9.4 Device Functional Modes
      1. 9.4.1 Toggle Mode
      2. 9.4.2 Differential Mode
      3. 9.4.3 Power-Down Mode
    5. 9.5 Programming
      1. 9.5.1 Stand-Alone Operation
        1. 9.5.1.1 Streaming Mode Operation
      2. 9.5.2 Daisy-Chain Operation
      3. 9.5.3 Frame Error Checking
    6. 9.6 Register Maps
      1. 9.6.1  NOP Register (Offset = 00h) [reset = 0000h]
        1. Table 9. NOP Register Field Descriptions
      2. 9.6.2  DEVICEID Register (Offset = 01h) [reset = ----h]
        1. Table 10. DEVICEID Register Field Descriptions
      3. 9.6.3  STATUS Register (Offset = 02h) [reset = 0000h]
        1. Table 11. STATUS Register Field Descriptions
      4. 9.6.4  SPICONFIG Register (Offset = 03h) [reset = 0A24h]
        1. Table 12. SPICONFIG Register Field Descriptions
      5. 9.6.5  GENCONFIG Register (Offset = 04h) [reset = 7F00h]
        1. Table 13. GENCONFIG Register Field Descriptions
      6. 9.6.6  BRDCONFIG Register (Offset = 05h) [reset = FFFFh]
        1. Table 14. BRDCONFIG Register Field Descriptions
      7. 9.6.7  SYNCCONFIG Register (Offset = 06h) [reset = 0000h]
        1. Table 15. SYNCCONFIG Register Field Descriptions
      8. 9.6.8  TOGGCONFIG0 Register (Offset = 07h) [reset = 0000h]
        1. Table 16. TOGGCONFIG0 Register Field Descriptions
      9. 9.6.9  TOGGCONFIG1 Register (Offset = 08h) [reset = 0000h]
        1. Table 17. TOGGCONFIG1 Register Field Descriptions
      10. 9.6.10 DACPWDWN Register (Offset = 09h) [reset = FFFFh]
        1. Table 18. DACPWDWN Register Field Descriptions
      11. 9.6.11 DACRANGEn Register (Offset = 0Bh - 0Ch) [reset = 0000h]
        1. Table 19. DACRANGEn Register Field Descriptions
      12. 9.6.12 TRIGGER Register (Offset = 0Eh) [reset = 0000h]
        1. Table 20. TRIGGER Register Field Descriptions
      13. 9.6.13 BRDCAST Register (Offset = 0Fh) [reset = 0000h]
        1. Table 21. BRDCAST Register Field Descriptions
      14. 9.6.14 DACn Register (Offset = 14h - 1Bh) [reset = 0000h]
        1. Table 22. DACn Register Field Descriptions
      15. 9.6.15 OFFSETn Register (Offset = 21h - 22h) [reset = 0000h]
        1. Table 23. OFFSETn Register Field Descriptions
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure for Remote Ground Tracking
        1. 10.2.2.1 Generating 300mV Offset
        2. 10.2.2.2 Amplifier Selection
        3. 10.2.2.3 Passive Component Selection
      3. 10.2.3 Application Curves
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Documentation Support
    2. 13.2 Related Links
    3. 13.3 Receiving Notification of Documentation Updates
    4. 13.4 Community Resources
    5. 13.5 Trademarks
    6. 13.6 Electrostatic Discharge Caution
    7. 13.7 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • RHA|40
Thermal pad, mechanical data (Package|Pins)
Orderable Information

10.2.2 Detailed Design Procedure for Remote Ground Tracking

In order to make the DAC outputs follow the remote ground, the best approach is to level shift the reference input. Figure 67 depicts a method wherein both the REF and REFGND inputs are level shifted with respect to DUTGND. However, as the DAC doesn’t allow the REFGND to become negative compared to GND, an offset voltage of 300mV needs to be applied as shown. This method requires an external 2.5V reference and a way to generate a stable 300-mV reference. A dual opamp U1 is used to shift both REFGND and REF by (DUTGND + 300-mV offset). Table 24 provides the nodal analysis of the circuit. As evident, the DAC outputs track the DUTGND with an offset of 300mV. This offset can be easily compensated in software. Note that the absolute max values between REFGND and GND must be respected. When the absolute max values are reached, they should only be for a transient period and not for sustained amount of time.

Table 24. Nodal Analysis of the Circuit

DUTGND (GND±0.3V) REFGND PIN REF PIN VOUT-GND AT 0V CODE VOUT-GND AT 5V CODE VOUT-DUTGND AT 0V CODE VOUT-DUTGND AT 5V CODE
0V 0.3V 2.8V 0.3V 5.3V 0.3V 5.3V
0.3V 0.6V 3.1V 0.6V 5.6V 0.3V 5.3V
-0.3V 0V 2.5V 0V 5V 0.3V 5.3V