SBAS442D august   2008  – august 2023 DAC5311 , DAC6311 , DAC7311

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Device Comparison
  7. 6 Pin Configuration and Functions
  8. 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  Timing Diagrams
    8. 7.8  Typical Characteristics: AVDD = 5 V
    9. 7.9  Typical Characteristics: AVDD = 3.6 V
    10. 7.10 Typical Characteristics: AVDD = 2.7 V
  9. 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
    4. 8.4 Device Functional Modes
      1. 8.4.1 Power-Down Modes
    5. 8.5 Programming
      1. 8.5.1 Serial Interface
        1. 8.5.1.1 Input Shift Register
        2. 8.5.1.2 SYNC Interrupt
  10. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Microprocessor Interfacing
        1. 9.1.1.1 DACx311 to 8051 Interface
        2. 9.1.1.2 DACx311 to Microwire Interface
        3. 9.1.1.3 DACx311 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 DACx311
      3. 9.2.3 Bipolar Operation Using the DACx311
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Receiving Notification of Documentation Updates
    2. 10.2 Support Resources
    3. 10.3 Trademarks
    4. 10.4 Electrostatic Discharge Caution
    5. 10.5 Glossary
  12. 11Mechanical, Packaging, and Orderable Information

9.2.2 Using the REF5050 as a Power Supply for the DACx311

As a result of the extremely low supply current required by the DACx311, an alternative option is to use a REF5050 5-V precision voltage reference to supply the required voltage to the part, as shown in Figure 9-8. This option is especially useful if the power supply is too noisy or if the system supply voltages are at some value other than 5 V. The REF5050 outputs a steady supply voltage for the DACx311. If the REF5050 is used, the current needed to supply DACx311 is typically 110 μA at 5 V, with no load on the output of the DAC. When the DAC output is loaded, the REF5050 also needs to supply the current to the load. The total current required (with a 5 kΩ load on the DAC output) is:

Equation 6. 110 μA + (5 V / 5 kΩ) = 1.11 mA

The load regulation of the REF5050 is typically 0.002%/mA, which results in an error of 90 μV for the 1.1 mA current drawn from the device. This value corresponds to a 0.07 LSB error at 12 bits (DAC7311).

GUID-D611ADE7-922B-46DB-9D13-9BBDBA42F45C-low.gif Figure 9-8 REF5050 as Power Supply to DACx311

For other power-supply voltages, alternative references such as the REF3030 (3 V), REF3033 (3.3 V), or REF3220 (2.048 V) are recommended. For a full list of available voltage references from TI, see the TI web site at www.ti.com.