Atmel SAM W25 Xplained Pro [USER GUIDE]
42463A-MCU-06/2015
7
Data Field
Data Type
Example Content
Product Serial Number
ASCII string
1774020200000010’\0’
Minimum Voltage [mV]
uint16_t
3000
Maximum Voltage [mV]
uint16_t
3600
Maximum Current [mA]
uint16_t
30
3.3
Power Supply
The SAM W25 Xplained Pro kit can be powered either by USB or by an external power source through the 4-
pin power header, marked PWR. This connector is described in
“Xplained Pro Power Header” on page 8
.
The available power sources and specifications are listed in
Table 3-3, “Power Sources for SAM W25 Xplained
Pro” on page 7
.
Table 3-3. Power Sources for SAM W25 Xplained Pro
Power Input
Voltage Requirements
Current Requirements
Connector Marking
External power
5V ± 2 % (±100mV) for
USB host operation.
4.3V to 5.5V if USB host
operation is not required
Recommended
minimum is 1A to
be able to provide
enough current for
connected USB
devices and the board
itself. Recommended
maximum is 2A due
to the input protection
maximum current
specification.
PWR
Embedded debugger
USB
4.4V to 5.25V
(according to USB spec)
500mA (according to
USB spec)
DEBUG USB
Target USB
4.4V to 5.25V
(according to USB spec)
500mA (according to
USB spec)
TARGET USB
The kit will automatically detect which power sources are available and choose which one to use according to
the following priority:
1. External power.
2. Embedded debugger USB.
3. Target USB.
Note
External power is required when the 500mA through the USB connector is not enough to power a
connected USB device in a USB host application.
3.3.1
Measuring SAM W25 Power Consumption
As part of an evaluation of the SAM W25 it can be of interest to measure its power consumption. Because
the device has a separate power plane (VCC_MCU_P3V3) on this board it is possible to measure the current
consumption by measuring the current that is flowing into this plane. The VCC_MCU_P3V3 plane is connected
via a jumper to the main power plane (VCC_TARGET_P3V3) and by replacing the jumper with an ammeter it is
possible to determine the current consumption. To locate the current measurement header, refer to
Figure 1-1,
“SAM W25 Xplained Pro Evaluation Kit Overview” on page 4
.
Warning
Do not power the board without having the jumper or an ammeter mounted. This can cause the
SAM W25 to be powered through its I/O pins and cause undefined operation of the device.
3.4
Standard Headers and Connectors
3.4.1
Xplained Pro Standard Extension Header
All Xplained Pro kits have one or more dual row, 20-pin, 100mil extension headers. Xplained Pro boards have
male headers while Xplained Pro extensions have their female counterparts. Note that all pins are not always
