Power Tree

USB-C PD Input

The main power comes from the USB-C PD power adapter. The power adaptor must provide at least 12V, and up to 1.5A. The MAX77958 with its specific firmware takes care of all the negotiation with the power adapter.

The MAX77958 is configured to prioritize voltage versus current. As an example, if the supply can generate 20V and 3A, as well as 12V and 5A, the selected supply will be 20V and 3A. The minimum voltage and current from the external supply must be 12V/1.5A.

Once the MAX77958 has negotiated the power with the external USB power adapter, and the FPGA is initialized (Power_good from FMC connector), the MAX77958 will generate the enabling signal for the power regulators (Power_on_good). If something fails, a red LED will indicate the failure.

Available Rails

The CN0585 board has 13 different rails:

https://media.githubusercontent.com/media/analogdevicesinc/documentation/main/docs/solutions/reference-designs/eval-cn0585-fmcz/images/cn0585_available_rails.jpg

Some of these rails are exposed in the EVAL-CN0585-FMCZ expansion connector, as well as some of the rails coming from the FPGA:

Power rail name

Voltage

USB-PD

Defined by USB power

3P3V

+3.3V from FPGA

VADJ

Logic supply used by the FPGA

3V3_EEPROM

+3.3V from the FPGA to power the EEPROM

+15V

+15V generated by the LTM8049

-15V

-15V generated by the LTM8049

+12V_ANALOG

+12V rail from LT3045-1

-12V_ANALOG

-12V rail from LT3094

VIO

Input rail that defines the logic voltage from the personality board to the EVAL-CN0585-FMCZ. If not used connect to 3P3V

Note

The maximum current for each rail depends on the maximum current from the previous regulator. As an example, the LT3094 is connected to LTM8049 so, if you use the LTM8049 in your expansion board, the maximum current from the LT3094 cannot be the maximum that the component could provide.