IWR6843ISK: IWR6843 power management

Lukas Herrmann

Part Number: IWR6843ISK
Other Parts Discussed in Thread: MMWAVEICBOOST, , LP87702

Hi experts,

I am confused about the power management on the MMWAVEICBOOST and IWR6843ISK development board.

My intention was to use the same ICs for generating the supply voltages as it is used at the development board but now I have a few questions about the implementation.

How is it possible that the radar chip configures the PMIC(LP87702) which is the power source of the radar chip itself?

Which part of the software does send the I2C commands to the PMIC and how is the workflow? Where can I find the code to change these settings.

Thanks,

Lukas

over 5 years ago

0 Charles Oladimeji over 5 years ago

TI__Mastermind 33805 points

Hi,

The radar chip does not configure the PMIC, there is a one time programming (OTP) that is done on the PMIC during manufacture of the PMIC IC that sets the registers and internal workings of the chip.

You can write to the PMIC using the radar to change some properties when both are already operational, but the boot up of the PMIC is independent and happens before the Radar IC is powered, as the PMIC provides the power on the voltage rails of the IC.

Please see PMIC datasheet for the register information.

Regards,

Charles O

0 Lukas Herrmann over 5 years ago in reply to Charles Oladimeji

Intellectual 280 points

Hi Charles,

thank you very much for you answer! Now the functionality is clear to me. This makes the hardware design a lot easier.

Besides, can you tell me something about the VPP pin? It is not clearly specified in the datasheet and I am not sure how to connect it. I want to avoid an additional 1.7 V voltage supply.

Kind regards,

Lukas

0 Charles Oladimeji over 5 years ago in reply to Lukas Herrmann

TI__Mastermind 33805 points

This VPP pin is only needed for certain devices. please see linked post below for more on this

https://e2e.ti.com/support/sensors/f/1023/t/771816?IWR6843ISK-IWR6843-custom-design-and-1-7V-VPP

Sensors

Sensors forum

IWR6843ISK: IWR6843 power management