Power Measurements - Analog Devices ADSP-BF518F EZ-Board Manual

For more information about daughter boards, visit the Analog Devices
Web site at:
http://www.analog.com/processors/tools/blackfin
Limits to current and interface speed must be taken into consideration
when using the expansion interface II. Current for the expansion
interface II is sourced from the EZ-Board; therefore, the current should be
limited to 1A for 5V and 500 mA for the 3.3V planes. 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 Measurements

Several locations are provided for measuring the current draw from vari-
ous power planes. Precision 0.1 ohm shunt resistors are available on the
VDDINT, VDDEXT, VDDMEM, and VDDFLASH voltage domains.
For current draw measuments, the associated jumper (
removed. Once the jumper is removed, voltage across the resistor can be
measured using an oscilloscope. Once voltage is measured, current can be
calculated by dividing the voltage by 0.1. For the highest accuracy, a dif-
ferential probe should be used for measuring voltage across the resistor.
For more information, see
"VDDEXT Power Jumper (P9)" on page
Jumper (P10)" on page
page 2-17.
ADSP-BF518F EZ-Board Evaluation System Manual
Using the ADSP-BF518F EZ-Board
"VDDINT Power Jumper (P8)" on page
2-17, and "VDDFLASH Power Jumper (P11)" on
.
P8—11
2-17, "VDDMEM Power
) must be
2-16,
1-27