SLOA194A May   2014  – January 2022 DRV2603 , DRV2604 , DRV2604L , DRV2605 , DRV2605L , DRV2605L-Q1 , DRV2624 , DRV2625 , DRV2667

 

  1.   Trademarks
  2. 1Introduction
    1. 1.1 Eccentric Rotating Mass
    2. 1.2 Linear Resonant Actuator
    3. 1.3 Piezo Actuator
  3. 2How to Measure Energy
    1. 2.1 Current Consumption
    2. 2.2 Energy Consumption
    3. 2.3 Current Versus Acceleration
  4. 3Energy Consumption Comparisons for ERM, LRA and Piezo
  5. 4Energy Consumption Advantage of DRV260x and DRV262x Drivers
  6. 5Appendix A Energy Consumption of Actuators
  7. 6Appendix B. Test Setup Picture
  8. 7Appendix C. Energy Consumption Calculation for Smartphone Scenarios
  9. 8Revision History

2 How to Measure Energy

In this document, we evaluated the AAC 1036C LRA, Sanyo NRS2574I ERM, and SEMCO PHAT423535XX Piezo module. All the graphs were taken on the DRV2604EVM-CT and DRV2667EVM-CT. There is no significant difference in resulting energy consumption between DRV260x and DRV262x driver families. Below is the legend for the oscilloscope channels:

C1: The wave of OUT+

C2: The wave of OUT–

Math: The wave of C1-C2

C3: Acceleration

C4: Mean current

Energy consumption is very important for portable applications, especially for wearable products like smart watches, bands, and fitness trackers. This section explains how to measure energy consumption and compares the energy advantages of each actuator.

There are three ways to measure the energy in haptics.

  • Current Consumption
  • Energy Consumption
  • Current versus Acceleration

The following sections explore these different methods: