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

4 Boost Converter Output Voltage

Set the boost converter based on the rated or maximum voltage required by the load. Add an additional 5 V to provide headroom when using the amplifier. Use Equation 1 to calculate the boost voltage.

Equation 1. VBOOST = VPEAK + 5 V
Symbol Description Value Unit
VBOOST Boost output voltage - V
VPEAK Peak amplifier output voltage - V

The boost output voltage is programmed by two external resistors shown in the following diagram:

GUID-2B346CAA-A8D5-4A29-AAFF-74798C6791F7-low.gif

The boost feedback resistors can be calculated using equation Equation 2:

Equation 2. GUID-8CA75167-4034-4639-8169-EA8B1C450CFF-low.gif
Note:

Ensure that the sum of R1 and R2 is greater than 400 kΩ to prevent large leakage currents due to high voltages on VBOOST.