SLVAFL4 august   2023 TPS61299

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction of Smart Watch Fast Transient Performance Requirements
  5. 2TPS61299 Fast Transient Performance Introduction
    1. 2.1 Fast Transient Mode Setting
  6. 3Standby Time Calculation
  7. 4Test Report Based on TPS61299 Solution
    1. 4.1 Load Transient Test for TPS61299 and TPS61099
    2. 4.2 Efficiency and Load Regulation
    3. 4.3 Output Ripple Test for TPS61299 and TPS61099
  8. 5Conclusion
  9. 6References

3 Standby Time Calculation

To see the benefits of fast transient performance in smart band applications visually, the following assumptions are made based on the actual market application and TPS61299 application with fast transient mode.

where:

  • The LED flashing frequency is f and the LED light time is tpwm
  • The energy loss generated by the LED light is PLED and the energy generated by system is Psys.
  • When flicking, the power consumption of LED is PAFE
  • The capacity of Li battery is Ebat.

The energy loss of LED is:

Equation 1. P A F E = P L E D t p w m f

The standby time of the actual market application is :

Equation 2. t = E b a t P s y s + P L E D t p w m f

Extended standby time is:

Equation 3. t e x t e n d = t 2 - t 1

t1 is the standby time of market application and t2 is the standby time of TPS61299 application

Table 3-1 shows the parameter of the actual market application and TPS61299 application with fast transient mode:

Table 3-1 Parameter of Smart Watch Application
Parameter Value Parameter Value Parameter Value
tpwm1 60 us f 50Hz PLED 0.3 mW
tpwm2 120 us Ebat 450mAh Psys 1.159 mW

According to the parameter and equation, the energy loss of the actual market application and TPS61299 application with fast transient mode are 0.18 mW, 0.09 mW separately. The standby time of the actual market application is 14.00 days and the standby time of TPS61299 application with fast transient mode is 15.01 days, so TPS61299 application with fast transient mode can extent standby time 1.01 days.