SBAS439C August   2008  – July 2015 DAC8311 , DAC8411

PRODUCTION DATA.  

  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Device Comparison
  6. Pin Configuration and Functions
  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: 14-Bit
    7. 7.7 Timing Requirements: 16-Bit
    8. 7.8 Typical Characteristics
      1. 7.8.1 Typical Characteristics: AVDD = 5 V
      2. 7.8.2 Typical Characteristics: AVDD = 3.6 V
      3. 7.8.3 Typical Characteristics: AVDD = 2.7 V
  8. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 DAC Section
      2. 8.3.2 Resistor String
      3. 8.3.3 Output Amplifier
      4. 8.3.4 Power-On Reset to Zero-Scale
    4. 8.4 Device Functional Modes
      1. 8.4.1 Power-Down Modes
    5. 8.5 Programming
      1. 8.5.1 DAC8311 Serial Interface
        1. 8.5.1.1 DAC8311 Input Shift Register
        2. 8.5.1.2 DAC8311 SYNC Interrupt
      2. 8.5.2 DAC8411 Serial Interface
        1. 8.5.2.1 DAC8411 Input Shift Register
        2. 8.5.2.2 DAC8411 SYNC Interrupt
  9. Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Microprocessor Interfacing
        1. 9.1.1.1 DAC8x11 to 8051 Interface
        2. 9.1.1.2 DAC8x11 to Microwire Interface
        3. 9.1.1.3 DAC8x11 to 68HC11 Interface
    2. 9.2 Typical Applications
      1. 9.2.1 Loop Powered Transmitter
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
        3. 9.2.1.3 Application Curves
      2. 9.2.2 Using the REF5050 as a Power Supply for the DAC8x11
      3. 9.2.3 Bipolar Operation Using the DAC8x11
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Related Links
    2. 12.2 Community Resources
    3. 12.3 Trademarks
    4. 12.4 Electrostatic Discharge Caution
    5. 12.5 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

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メカニカル・データ(パッケージ|ピン)
サーマルパッド・メカニカル・データ

11 Layout

11.1 Layout Guidelines

A precision analog component requires careful layout, adequate bypassing, and clean, well-regulated power supplies.

The DAC8x11 offers single-supply operation; it will often be used in close proximity with digital logic, microcontrollers, microprocessors, and digital signal processors. The more digital logic present in the design and the higher the switching speed, the more difficult it will be to achieve good performance from the converter.

Because of the single ground pin of the DAC8x11, all return currents, including digital and analog return currents, must flow through the GND pin. Ideally, GND would be connected directly to an analog ground plane. This plane would be separate from the ground connection for the digital components until they were connected at the power entry point of the system.

The power applied to AVDD should be well-regulated and low-noise. Switching power supplies and dc/dc converters often have high-frequency glitches or spikes riding on the output voltage. In addition, digital components can create similar high-frequency spikes as the internal logic switches state. This noise can easily couple into the DAC output voltage through various paths between the power connections and analog output. This condition is particularly true for the DAC8x11, as the power supply is also the reference voltage for the DAC.

As with the GND connection, AVDD should be connected to a 5 V power supply plane or trace that is separate from the connection for digital logic until they are connected at the power entry point. In addition, TI strongly recommends the 1 μF to 1 μF and 0.1 μF bypass capacitors. In some situations, additional bypassing may be required, such as a 100 μF electrolytic capacitor or even a Pi filter made up of inductors and capacitors—all designed to essentially low-pass filter the 5 V supply, removing the high-frequency noise.

11.2 Layout Example

DAC8311 DAC8411 layout_sbas439.gifFigure 90. Recommended Layout