SWRA689 February 2022 AWR6843 , AWR6843AOP , IWR6843 , IWR6843AOP
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TI mmWave Sensors enable high performance measurement and object detection over a variety of applications but some designs require minimal power consumption. This Application Note will showcase various power-saving techniques on the mmWave sensor where power consumption concerns are critical. Using this guide will enable one to implement various optimizations for evaluation. Moreover this guide discusses the tradeoffs involved as well.
The power saving techniques discussed in this guide can be implemented exclusively through software. Using the AWR6843 Evaluation Module (EVM), mmWave-SDK, and Code Composer Studio IDE one can replicate the results shown here with the use of standard laboratory equipment for power measurement.
The highly integrated nature of the AWR/IWR6843 Sensor allows for varying schemes of power optimization. For example an application that makes use of only 1Tx/1Rx will see less power consumed during active chirp time than a multi-Tx/Rx application where more angular resolution is required. As such one should be aware of the various performance compromises that result from optimizing for power. However the benefit of integration allows the optimizations to be implemented through software that can even be configured at runtime.
All of the power saving techniques discussed in this document can be performed using the AWR6843ISK EVM and MMWAVEICBOOSTboards (Note: the MMWAVEICBOOST board is not required for evaluation, but is required for debug and is highly recommended). Also the mmWave-SDK 3.5 is leveraged using the 68xx Low Power Demo available on the TI Resource Explorer.
The 68xx Low Power Demo is a modified version of the mmWave-SDK 68xx Out-of-Box Demo – HWA Version with the addition of software libraries and code level changes for power optimization. You should first run the 68xx Low Power Demo using the steps from User Guide before proceeding with power measurement.
By default, the device boots once at power on, chirps based on end configuration provided by user, and leaves all subsystems running (even if they are not used). In many cases, this default behavior is fine. However, for power-sensitive applications, action can be taken to reduce the power consumption in both the Acquisition and Inter-frame Periods
Active Mode optimization is achieved through minimizing the acquisition period (see Figure 3-1).
During the acquisition period the following occurs: