SBAS794E november   2018  – august 2023 DAC60501 , DAC70501 , DAC80501

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Device Comparison Table
  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: SPI Mode
    7. 7.7  Timing Requirements: I2C Standard Mode
    8. 7.8  Timing Requirements: I2C Fast Mode
    9. 7.9  Timing Requirements: I2C Fast-Mode Plus
    10. 7.10 Timing Diagrams
    11. 7.11 Typical Characteristics
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 DAC Architecture
        1. 8.3.1.1 DAC Transfer Function
        2. 8.3.1.2 DAC Register Structure
        3. 8.3.1.3 Output Amplifier
      2. 8.3.2 Internal Reference
        1. 8.3.2.1 Solder Heat Reflow
      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 Interface
        1. 8.5.1.1 SPI Mode
          1. 8.5.1.1.1 SYNC Interrupt
        2. 8.5.1.2 I2C Mode
          1. 8.5.1.2.1 F/S Mode Protocol
          2. 8.5.1.2.2 I2C Update Sequence
            1. 8.5.1.2.2.1 Address Byte
            2. 8.5.1.2.2.2 Command Byte
            3. 8.5.1.2.2.3 Data Byte (MSDB and LSDB)
          3. 8.5.1.2.3 I2C Read Sequence
    6. 8.6 Register Map
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Charge Injection
        2. 9.2.2.2 Voltage Droop
        3. 9.2.2.3 Output Offset Error
        4. 9.2.2.4 Switch Selection
        5. 9.2.2.5 Amplifier Selection
        6. 9.2.2.6 Hold Capacitor Selection
      3. 9.2.3 Application Curves
    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 Documentation Support
      1. 10.1.1 Related Documentation
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

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

8.3.2 Internal Reference

The DAx0501 family of devices includes a 2.5-V precision band-gap reference that is enabled by default. Operation from an external reference is supported by disabling the internal reference in the REF_PWDWN bit (address 3h). The internal reference is externally available at the VREFIO pin, and can be used to drive external circuitry. At power-on reset, the internal reference is enabled. This enabled reference can result in current being sunk or sourced from the device to an external reference source. When using an external reference, use a series resistance that is larger than 1 kΩ to reduce the current at start-up to be less than 5 mA. After the internal reference is disabled, the input becomes high impedance. For noise filtering, use a minimum 150-nF capacitor between the reference output and AGND.

The reference voltage to the device, either from the internal reference or an external one, can be divided by a factor of two by setting the REF-DIV bit (address 4h) to 1. The REF-DIV bit provides additional flexibility in setting the full-scale output range of the DAC output. Make sure to configure REF-DIV so that there is sufficient headroom from VDD to the DAC operating reference voltage, VREFIO (see Equation 1). See Section 7.3 for more information. The short-circuit current of the internal reference is limited by design to approximately 100 mA.

Improper configuration of the reference divider triggers a reference alarm condition. In this case, the reference buffer is shut down, and all the DAC outputs go to 0 V. The DAC data registers are unaffected by the alarm condition, thus enabling the DAC output to return to normal operation after the reference divider is configured correctly.