Power Architecture - Analog Devices ADSP-BF526 EZ-Board Manual

Power Architecture

power to the EZ-Board, the expansion interface II 5V current is reduced
to 400mA. If more current is required, then a separate power connector
and a regulator must be designed on a daughter card. Additional circuitry
can add extra loading to signals, decreasing their maximum effective
speed.

Analog Devices does not support and is not responsible for the
effects of additional circuitry.
Power Architecture
The ADSP-BF526 EZ-Board has three primary voltage sources, a lithium
ion battery (740 mAh), a 5V wall adaptor, and
cable. There is an OR'ing opamp circuit, which allows the board to draw
power from any supply source that has the highest voltage potential. For
example, if the battery is turned on while the board is plugged into the 5V
wall adaptor (
P14
The VDDEXT, VDDMEM, and SDRAM power are 1.8V and supplied
by an ADP2105 regulator (
The ADSP-BF526 core voltage, VDDINT, is selected via the I
face of the processor. The default is 1.4V. An I
interfaces the 1.8V signals
digital potentiometer (digipot,
tors for a low drop-out (LDO) regulator ADP1715 (
example located in the ADSP-BF526 directory of CCES or VisualDSP++
to learn how to change the VDDINT voltage.
priate step settings for the digipot and corresponding voltage values.
1-30
), the board runs from the 5V wall adaptor.
).
VR3
and
SDA SCL
). The digipot sets the feedback resis-
U34
ADSP-BF526 EZ-Board Evaluation System Manual
supplied over a USB
VBUS
2
C voltage translator (
of the processor to the AD5258
). See the POST
VR5
Table 1-3 shows the appro-
2
C inter-
)
U39