SLOA198A September 2014 – December 2021 DRV2665 , DRV2667 , DRV2700 , DRV8662
- Trademarks
- 1 Boost Converter Basics
- 2 DRV8662, DRV2700, DRV2665, and DRV2667 Boost Converter
- 3 Configuring the Boost Converter
- 4 Boost Converter Output Voltage
- 5 Calculating the Load Current
- 6 Selecting an Inductor
- 7 Calculate the Maximum Boost Current
- 8 Output Capacitor Selection
- 9 Input Capacitor Selection
- 10PCB Layout
- 11Examples
- 12Revision History
7 Calculate the Maximum Boost Current
The maximum support boost current is estimated using Equation 8 and Equation 9.
First calculate the maximum duty cycle of the hysteretic converter. Equation 8 assumes worst-case duty cycle during maximum current.
Equation 8. 
| Symbol | Description | Value | Unit |
|---|---|---|---|
| D | Boost Duty Cycle | – | – |
| Vin_min | Minimum VDD | – | V |
| ETA (η) | Boost Efficiency | 60 | % |
| Vboost | Boost Voltage | – | V |
If the approximate and the actual measurements do not align perfectly, then you can adjust η, which is the efficiency of the boost converter.
Equation 9. 
| Symbol | Description | Value | Unit |
|---|---|---|---|
| Iboost_max | Maximum boost current | – | A |
| Ilimit | Boost current limit (REXT) | – | A |
| D | Boost duty cycle | – | – |
Iboost_max is the maximum boost current the boost can deliver to the amplifier. Compare this current to the current calculated for the load current. The boost current should be higher than the load current.