SLASFK2 December   2024 DAC121S101-SEP

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Timing Requirements
    7. 5.7 Timing Diagram
    8. 5.8 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 DAC Section
      2. 6.3.2 Resistor String
      3. 6.3.3 Output Amplifier
    4. 6.4 Device Functional Modes
      1. 6.4.1 Power-On Reset
      2. 6.4.2 Power-Down Modes
    5. 6.5 Programming
      1. 6.5.1 Serial Interface
      2. 6.5.2 Input Shift Register
  8. 7 Application and Implementation
    1. 7.1 Application Information
      1. 7.1.1 Bipolar Operation
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
      3. 7.2.3 Application Curve
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Documentation Support
    2. 8.2 Receiving Notification of Documentation Updates
    3. 8.3 Support Resources
    4. 8.4 Trademarks
    5. 8.5 Electrostatic Discharge Caution
    6. 8.6 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

6.5.2 Input Shift Register

The input shift register, Figure 6-2, has sixteen bits. The first two bits are don't care bits, and are followed by two bits that determine the mode of operation (normal mode or one-of-three power-down modes). The contents of the serial input register are transferred to the DAC register on the sixteenth falling edge of SCLK. See also Figure 5-1.

DAC121S101-SEP Input Register Contents Figure 6-2 Input Register Contents

Normally, the SYNC line is kept low for at least 16 falling edges of SCLK and the DAC is updated on the 16th SCLK falling edge. However, if SYNC is brought high before the 16th falling edge, the shift register is reset and the write sequence is invalid. In this case, the DAC register is not updated, and there is no change in the mode of operation or in the output voltage.