SLOA198A September   2014  – December 2021 DRV2665 , DRV2667 , DRV2700 , DRV8662

 

  1.   Trademarks
  2. 1 Boost Converter Basics
  3. 2 DRV8662, DRV2700, DRV2665, and DRV2667 Boost Converter
    1. 2.1 DRV8662, DRV2700, DRV2665, and DRV2667 Boost Converter Efficiency
      1. 2.1.1 Boost Efficiency vs Boost Current
    2. 2.2 DRV8662, DRV2700, DRV2665, and DRV2667 Boost Converter Load Regulation
      1. 2.2.1 Boost Regulation vs Current
  4. 3 Configuring the Boost Converter
  5. 4 Boost Converter Output Voltage
  6. 5 Calculating the Load Current
  7. 6 Selecting an Inductor
    1. 6.1 Inductance Rating
    2. 6.2 Saturation Current Rating
    3. 6.3 Thermal Current Rating
    4. 6.4 Choosing REXT
    5. 6.5 What to Avoid: Using Incorrect Inductor Current Ratings
  8. 7 Calculate the Maximum Boost Current
  9. 8 Output Capacitor Selection
  10. 9 Input Capacitor Selection
  11. 10PCB Layout
    1. 10.1 What to Avoid: Incorrect Inductor Placement
  12. 11Examples
    1. 11.1 Example: Based on the DRV8662EVM
      1. 11.1.1 Configure the Boost Voltage
      2. 11.1.2 Configure the Inductor Current
      3. 11.1.3 Boost Performance Results
    2. 11.2 Example: Based on the DRV2667EVM-CT with 25-nF Piezo Module
      1. 11.2.1 Configure the Boost Voltage
      2. 11.2.2 Configure the Inductor Current
      3. 11.2.3 Boost Performance Results
  13. 12Revision History

3 Configuring the Boost Converter

This section describes the basic steps for configuring the boost converter. See the following sections for more details.

  1. Select the boost voltage.
    Based on the rated voltage of the load, set the feedback resistors to the appropriate boost voltage (Section 4).
  2. Calculate the load current.
    Estimate the maximum required load current to support the voltage, capacitance, and frequency of the load (Section 5).
  3. Select an inductor.
    Choose an inductor with an inductance value between 3.3 µH and 22 µH, and a saturation current rating more than 1 A (Section 6).
  4. Set the current limit and REXT resistor.
    Calculate the REXT resistor based on the saturation current of the inductor (Section 6.4).
  5. Compare the maximum boost current.
    Compare the maximum boost current with the required load current calculated in step 2 (Section 7).
  6. Choose an input and output capacitor.
    Input and output capacitors help reduce the effects of ripple and transient load currents on the supply and output voltages (Section 8).
  7. Verify performance.
    Verify the performance of the components selected.