SLVAFW1 August   2024 DRV8818

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Method A: Reducing VREF Manually
    1. 2.1 Experiment and Results
  6. 3Method B: Standstill Power Saving Mode
    1. 3.1 Experiment and Results
  7. 4Summary
  8. 5References

2 Method A: Reducing VREF Manually

In low cost stepper drivers such as the DRV8818, the peak current regulation value, ITRIP, in the motor current sine wave is calculated using the equation:

Equation 1. I T R I P = V R E F × K

Where K is a constant. For example, in DRV8818,

Equation 2. I T R I P = V R E F × 1 8 × R S E N S E

Where, RSENSE is the value of sense resistor in ohms. This allows manual control of current regulation value at every step by the voltage on the VREF pin.