I have spoken with the Hardware Team regarding this matter, and they advised that the EZ-KIT Lite uses the VDDVR pin as the input voltage reference for the internal voltage regulation circuit. The EZ-KIT Lite does use the internal voltage regulator - you will see that the resistor on the output of the external regulator circuit is not populated.
I missed something on this, pls. take a look at the following pics, datasheet says that if not using internal regulator tie VDDVR pin(F15 Ball) to VDDEXT, this is what is done to F15 pin of BF548 in EVK schematics, it does not mention the F15 as VDDVR pin, instead it is written as VDDEXT
Below is the library of EVK
Below is the pin out of BF548 from datasheet
Below is the voltage regulation paragraph of datasheet at page no 16 of datasheet:
Even if F15 ball is termed as VDDEXT initially but still the datasheet says that to use internal regulator of the device we have to use the following circuit given in datasheet at page-17 for VDDVR pin, but this is not done, instead F15 is connected to VDDEXT voltage rather than VDDINT produced on the board. Pls. help
On page-32 of datasheet following is mentioned on point-13
VDDVR: This pin must always be connected. If the internal voltage regulator is not being used, this pin may be connected to VDDEXT Otherwise it should be powered according to the VDDVR specification. For automotive grade models, the internal voltage regulator must not be used and this pin must be tied to V DDEXT
VDDVR should be connected to the input voltage and not VDDINT. VDDEXT is 3.3V and is connected to VDDVR. VDDVR and VDDINT are two separate signals. The internal regulator uses VDDVR as the input voltage reference for the regulator and therefore it needs to be higher than the voltage that you want on VDDINT.
The circuit on figure 6 has been followed. If you look at the circuit on the top right of sheet 16 of the EZ-Kit schematic you will see that it is the same as the circuit listed in the datasheet.
Thanks for your reply.
I want to know the sequencing related to VDDINT rail.
Because EZ-Kit Lite is using internal regulator controlled through VROUT pin, so during power on reset how is power sequencing met because power sequencing on page-42 of Datasheet says that reset should be de-asserted only after all Power domain rails are stable. So how can VDDINT be generated as it is controlled through VROUT pin, but processor is still in reset?
So does VROUT pin belong to always powered domain?