Understanding PSoC 6 BLE Prototyping Kit schematics

[MaH_4035971]

Hello,

I am trying to figure out how the EZ-BLE module is wired up in the prototyping kit as I would like to use it separately in a project.

I was reading the page 4 of the schematics CY8CPROTO-063-BLE Schematic.pdf but I am not 100% sure where VDD (MCU power input) is coming from. My understanding is that the power line is VTARG (coming from the other half of the board, the one with the programming chip) and it is connected to VDD via the 0 ohm resistor R28. Is that correct ?

If I want to use a power regulator such as U6, can I connect VCC out of the regulator to VDD ? My application uses many analog input, could anyone recommend a good regulator with 2 separate power lines ? Ideally an ultra-low power PMIC such as the BQ25150 but with two LDO.

Just to make things clear, can anyone explain briefly VTARG, VBACKUP, VREF and of course the difference between VDD and VCC. The only thing I am sure of is VIN...

Thank you !

[BragadeeshV · Accepted solution]

Hi s1606945_4035971​,

When the two boards (kitprog and EZ-BLE module) are connected together, there are two ways in which you can power the PSoC MCU:

1. The power supply system uses 5 V from the USB connector as the input to a voltage regulator (U2) on the KitProg2 section of the board. This regulator provides 3.3 V to the PSoC 6 MCU by default. Provisions have been added so that the output can be easily changed to 2.5 V or 1.8 V by adding either R9 or R41 zero-ohm resistors respectively. If R9 is loaded output will be 2.5V. If R41 is loaded, output will be 1.8V.

2. You can also connect an external power supply to the board at P6.VDD that is present on pin 20 of J1 for low-voltage applications.

If the PSoC 6 MCU section of the board is disconnected from the KitProg2 side by breaking the board between J4 and J5, there are two power options.

1. Power the board directly with the required voltage at the target voltage (P6.VDD) on connector J1, pin 20

2. Load the optional components for the PSoC 6 MCU regulator and apply a voltage at the VIN connector (J2, pin 20).

VTARG is the power supply that goes to the PSoC 6 MCU either through the USB connector or external supply

VREF is the voltage reference pin for analog block

VBackup is the power supply for the backup domain -> This rail powers a small set of peripherals that includes an RTC, WCO, and a small number of retention registers. This rail is independent of all other rails and can exist even when other rails are absent.

Regards,

Bragadeesh