XMOS XK-EVK-XU316, Manual

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xcore.ai Explorer v2 Board Manual
4.3 Power and Operating Requirements
The xcore.ai explorer board requires a 5V power source that is normally provided through
the micro-USB cable J3. The voltage is converted by on-board regulators to the 0V9, 1V8
and 3V3 supplies used by the components.
To ease measurements of core current the board includes a sense-amp. You can measure
the current by putting a voltmeter across J2. A 1V reading on J2 is equivalent to 500 mA
core current (450 mW at 0.9V).
By default, VDDIOL and VDDIOR are powered at 3V3. If you need different voltage levels
you can change the following:
·
You can make VDDIOL 1V8 by removing R35, and soldering 0R resistors on R5 and
R36.
·
You can make both VDDIOL and VDDIOR 1V8 by removing R35 and R37. and soldering
0R resistors on R5, R6, R36, and R38
The table below summarises the default state of the VDDIO power supplies (row 1), and
resistors that can be added or removed in order to change the VDDIO supply voltages.
VDDIOL VDDIOR R5 R6 R35 R36 R37 R38
3V3 3V3 DNF DNF Fitted DNF Fitted DNF
1V8 3V3 Added DNF Removed Added Fitted DNF
1V8 1V8 Added Added Removed Added Removed Added
Changing the resistors to operate at 1V8 must be done with care as incorrect settings
may damage the device. The resistors are located on the back of the board as shown in
Figure 13 .
Figure 13:
Resistors that
govern VDDIO
on the back of
the board.
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