SLASF08 December   2021 DAC43508 , DAC53508

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configurations and 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: SPI
    7. 7.7  Timing Requirements: Logic
    8. 7.8  Timing Diagrams
    9. 7.9  Typical Characteristics: Static Performance
    10. 7.10 Typical Characteristics: Dynamic Performance
    11. 7.11 Typical Characteristics: General
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Digital-to-Analog Converter (DAC) Architecture
        1. 8.3.1.1 DAC Transfer Function
        2. 8.3.1.2 DAC Register Update and LDAC Functionality
        3. 8.3.1.3 CLR Functionality
        4. 8.3.1.4 Output Amplifier
      2. 8.3.2 Reference
      3. 8.3.3 Power-On Reset (POR)
      4. 8.3.4 Software Reset
    4. 8.4 Device Functional Modes
      1. 8.4.1 Power-Down Mode
    5. 8.5 Programming
      1. 8.5.1 Serial Peripheral Interface (SPI)
    6. 8.6 Register Map
      1. 8.6.1 DEVICE_CONFIG Register (address = 01h) [reset = 00FFh]
      2. 8.6.2 STATUS_TRIGGER Register (address = 02h) [reset = 0000h]
      3. 8.6.3 BRDCAST Register (address = 03h) [reset = 0000h]
      4. 8.6.4 DACn_DATA Register (address = 08h to 0Fh) [reset = 0000h]
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Programmable LED Biasing
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
        3. 9.2.1.3 Application Curve
      2. 9.2.2 Programmable Window Comparator
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
        3. 9.2.2.3 Application Curve
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Support Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

8.3.3 Power-On Reset (POR)

The DACx3508 family of devices includes a power-on reset (POR) function that controls the output voltage at power up. After the VDD supply has been established, a POR event is issued. The POR causes all registers to initialize to default values, and communication with the device is valid only after a 5-ms delay, when VDD reaches DAC operating range. The default value for the DAC data registers is zero-code. The DAC output remains at the power-up voltage until a valid command is written to a channel.

When the device powers up, a POR circuit sets the device to the default mode. The POR circuit requires specific VDD levels, as indicated in Figure 8-2, to make sure that the internal capacitors discharge and reset the device on power up. To make sure that a POR occurs, VDD must be less than 0.7 V for at least 1 ms. When VDD drops to less than 1.7 V but remains greater than 0.7 V (shown as the undefined region), the device may or may not reset under all specified temperature and power-supply conditions. In this case, initiate a POR. When VDD remains greater than 1.7 V, a POR does not occur.

GUID-58370186-C652-4C7A-A55D-EB3C5ED2D086-low.gifFigure 8-2 Threshold Levels for VDD POR Circuit