UG-1828
Preliminary Technical Data
Rev. PrC | Page 272 of 338
POWER SUPPLY ARCHITECTURE
The diagram in Figure 259 outlines the power supply configuration used on the ADRV9001 evaluation board. This configuration follows
the recommendations outlined in Table 108. This diagram includes the use of C/FB/C/FB cascaded filters and ferrite beads for additional
RF isolation. The use of ferrite beads and 0Ω resistors in EVB power supply solution accomplishes 3 goals:
•
Serve as place holders for ferrite beads or other filter devices that may be needed when users encounter RF noise problems in
their application and additional isolation is required. For more details regarding ferrite bead selection, refer to RF and Clock
Synthesizer Supplies section of this document.
•
Ensures following of power routing recommendations outlined in the Printed Circuit Board Layout Recommendations section.
Ferrite beads and resistor placeholders in series force the use of separate traces to deliver different power domains to the
ADRV9001 device.
•
Provide a place in the circuit where the current can be monitored and measured for debugging purposes. For this case, the 0Ω
components or ferrite bead can be replaced by very low-impedance shunt resistors and the voltage can be measured to
determine current to the specified input ball.
For more details on exact power supply implementation, refer to the ADRV9001 Customer Evaluation Board Schematic that is supplied
with an evaluation kit.
The ADRV9001 evaluation board also provides and on-board current and voltage sensors (ADM1293) which monitors and reports back
to TES power consumed by TRx in selected mode of operation. Idea here is to provide end user with live feedback from an evaluation
system regarding active power consumption. Current readbacks from those sensors are accurate within 2.5% tolerance. If those readback
numbers are used to estimate overall power for power supply design, user should add an extra power margin to accommodate dynamic
conditions. First paragraph in this section provides more suggestions.
EVB Power Supply overview
The diagram in Figure 259 outlines the Power Supply configuration used on ADRV9001 evaluation board. This supply architecture
follows conservative approach to the power supply design. Switch Mode regulator (ADP5056) is used to achieve power efficiency while
generating domains that supply ADRV9001. Remote sensing configuration is utilized to take in account voltage drop in filters and ensure
power domains accuracy at ADRV9001 input pins.
The ADP5056 contains three switch-mode step down regulators. Each of those regulators produces a different power domain that
supplies power to the ADRV9001. They operates as follow:
•
Channel 1 – generates 1.3V which supplies voltage for ADRV9001 1.3V power domains. Sensing is done after C/FB/C/FB
cascaded filters and current sensing shunt resistor ensuring that 1.3V analog power domain voltage stays within datasheet
specification.
o
The ADRV9001 EVB supports also an optional 1.0V power domain. This domain could be generated by using an on-
board LDO (ADP1762) That LDO utilize its own remote sensing scheme to ensure that 1.0V analog power domain
voltage stays within datasheet specification.
•
Channel 2 - generates 1.0V which supplies voltage for ADRV9001 digital domain. Sensing is done after C/FB/C/FB cascaded
filters and current sensing shunt resistor to ensure that 1.0V digital power domain voltage stays within datasheet specification.
•
Channel 3 - generates 1.8V which supplies voltage for ADRV9001 digital and analog power domains. The C/FB/C/FB cascaded
filters are used to isolate analog power domain from digital power domain. Since more than one power domain is produced
from single source, remote sensing is done before C/FB/C/FB cascaded filters.
