SLASF62A June   2024  – November 2024 DAC80516

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 - I2C Standard Mode
    7. 5.7  Timing Requirements - I2C Fast Mode
    8. 5.8  Timing Requirements - I2C Fast Mode Plus
    9. 5.9  Timing Requirements - SPI
    10. 5.10 Switching Characteristics
    11. 5.11 Timing Diagrams
    12. 5.12 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 Digital-to-Analog Converter (DAC) Architecture
        1. 6.3.1.1 DAC Register Structure
          1. 6.3.1.1.1 DAC Synchronous Operation
          2. 6.3.1.1.2 DAC Buffer Amplifier
          3. 6.3.1.1.3 DAC Transfer Function
      2. 6.3.2 Internal Reference
      3. 6.3.3 Power-On Reset (POR)
    4. 6.4 Device Functional Modes
      1. 6.4.1 Clear Mode
    5. 6.5 Programming
      1. 6.5.1 I2C Serial Interface
        1. 6.5.1.1 I2C Bus Overview
        2. 6.5.1.2 I2C Bus Definitions
        3. 6.5.1.3 I2C Target Address Selection
        4. 6.5.1.4 I2C Read and Write Operations
        5. 6.5.1.5 I2C General-Call Reset
      2. 6.5.2 Serial Peripheral Interface (SPI)
        1. 6.5.2.1 SPI Bus Overview
  8. 7 Register Map
    1. 7.1 DAC80516 Registers
  9. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Bipolar Voltage Output
    2. 8.2 Typical Application
      1. 8.2.1 Programmable High-Current Voltage Output Circuit
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
        3. 8.2.1.3 Application Curve
    3. 8.3 Initialization Setup
    4. 8.4 Power Supply Recommendations
    5. 8.5 Layout
      1. 8.5.1 Layout Guidelines
      2. 8.5.2 Layout Examples
  10. 9 Device and Documentation Support
    1. 9.1 Documentation Support
      1. 9.1.1 Related Documentation
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • RUY|28
Thermal pad, mechanical data (Package|Pins)
Orderable Information

8.2.1.2 Detailed Design Procedure

The transfer function of the output voltage is given by Equation 4.

Equation 4. V O U T P U T =   V D A C 1 + R 1 R 2

The resistance values can be chosen so that the quiescent current is negligible compared to the load current. For a desired load current of 10A at a desired VOUTPUT of 5V (with VDAC = 2.5V), choose R1 and R2 as 10kΩ each. This minimizes the quiescent current through the feedback network as 5V / 20kΩ = 250μA.

The base current, IB, for the transistor for a given load current IL is given by Equation 5.

Equation 5. I B = I C H F E =   1 H F E I L + V O U T P U T R 1 + R 2

Where:

  • IC = The collector current of the transistor
  • HFE = DC current gain of the transistor

VOUTPUT / (R1+R2) is equal to the previously calculated quiescent current, which is negligible compared to the load current (particularly for load currents above 1A). This simplifies the equation to Equation 6.

Equation 6. I B = I L H F E

To keep IB less than 20mA, HFE must be greater than IL / 20mA. In general, compensation capacitor C1 is not set by fixed equations, but rather by choosing values while observing the output small-signal step response.