SLOS861C March   2015  – January 2023 DRV2700

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Switching Characteristics
    7. 6.7 Typical characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Boost Converter and Control Loop
      2. 7.3.2 High-Voltage Amplifier
      3. 7.3.3 Fast Start-Up (Enable Pin)
      4. 7.3.4 Gain Control
      5. 7.3.5 Adjustable Boost Voltage
      6. 7.3.6 Adjustable Boost Current-Limit
      7. 7.3.7 Internal Charge Pump
      8. 7.3.8 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Boost + Amplifier Mode
      2. 7.4.2 Flyback Mode
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 AC-Coupled DAC Input Application
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1  Piezo Load Selection
          2. 8.2.1.2.2  Programming The Boost Voltage
          3. 8.2.1.2.3  Inductor and Transformer Selection
          4. 8.2.1.2.4  Programing the Boost and Flyback Current-Limit
          5. 8.2.1.2.5  Boost Capacitor Selection
          6. 8.2.1.2.6  Pulldown FET and Resistors
          7. 8.2.1.2.7  Low-Voltage Operation
          8. 8.2.1.2.8  Current Consumption Calculation
          9. 8.2.1.2.9  Input Filter Considerations
          10. 8.2.1.2.10 Output Limiting Factors
          11. 8.2.1.2.11 Startup and Shutdown Sequencing
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Filtered AC Coupled Single-Ended PWM Input Application
      3. 8.2.3 DC-Coupled DAC Input Application
      4. 8.2.4 DC-Coupled Reference Input Application
      5. 8.2.5 Flyback Circuit
    3. 8.3 System Example
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 Boost + Amplifier Configuration Layout Considerations
      2. 10.1.2 Flyback Configuration Layout Considerations
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Trademarks
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • RGP|20
Thermal pad, mechanical data (Package|Pins)
Orderable Information
8.2.1.2.4 Programing the Boost and Flyback Current-Limit

The peak current drawn from the supply through the inductor is set solely by the R(REXT) resistor. This peak current-limit is independent of the selected inductance value, but the inductor is capable of handling this programmed limit. Use Equation 3 to calculate the relationship between R(REXT) and I(LIM).

Equation 3. GUID-2C260E0A-9A05-4F94-AA9C-D539984F485C-low.gif

where

  • K = 10 500
  • Vref = 1.35 V
  • I(LIM) is the desired peak current-limit through the inductor or transformer
  • R(INT) = 60 Ω

For this design example, because the saturation current is 1.5 A, select 1 A for the I(LIM) value. Using Equation 3, the value of R(EXT) is approximately 14 kΩ.