SLYA068A May   2023  – December 2023 TMAG3001 , TMAG5253

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Low Power Modes
    1. 2.1 Power Cycling
      1. 2.1.1 Self Duty Cycled Low Power Operation
    2. 2.2 Conversion on Demand
    3. 2.3 Wake on Detection
    4. 2.4 Wake on Change
  6. 3Low Power Modes with Multiple Sensors
  7. 4Low Power Mode Design Examples
    1. 4.1 Design Example Scenario 2
    2. 4.2 Design Example Scenario 2
  8. 5Summary
  9. 6References
  10. 7Revision History

Design Example Scenario 2

For the second scenario, consider the case in which a wireless gaming controller is turned on and left unused (idle) for more than 2 hours. In this case, the user interfaces if left unused can be put in sleep mode by the microcontroller, to further save power. By placing the TMAG5273 in sleep mode, the current consumption per thumb stick can be reduced to 5 nA. And with a shutdown current of less than 10 nA for TMAG5253, the current consumed by triggers can also be reduced. Table 4-2 shows the analysis to understand the savings in power consumption just from the triggers and thumb sticks, for a 2-hour idle mode. In Table 4-2, assume that in active mode, the sensors are turned on for 50 μs once every 10 ms. Compare this scenario to the mode where the sensors are shutdown to save power. As shown in the power savings that we can achieve by just power cycling the devices during run time is more than 1000 times compared to the case where the sensors are power cycled.

Table 4-2 Power Savings in System for Scenario 2
Scenario 2 No Power savings Power Savings
Duration in Active mode 0.6 minutes 0 minutes
Duration disabled or in sleep mode 119.4 minutes 120 minutes
Supply voltage 1.8 V 1.8 V
Average current consumption per thumb stick using 1 TMAG5273 (if 2 magnetic channels are enabled) 20 μA at 100 Hz 5 nA
Average current consumption per trigger using 1 TMAG5253 10 μA at 100 Hz 20 nA
Power consumption of the system with 2 Triggers and 2 Thumb sticks (mWh) 60 μA at 100 Hz 50 nA