Atmel Xplained Pro Evaluation Kit ATSAM4E-XPRO ATSAM4E-XPRO Data Sheet
Product codes
ATSAM4E-XPRO
1151
SAM4E [DATASHEET]
Atmel-11157D-ATARM-SAM4E16-SAM4E8-Datasheet_12-Jun-14
42.5
Typical Connection
Figure 42-2.
Board Schematic to Interface Device Peripheral
42.5.1 USB Device Transceiver
The USB device transceiver is embedded in the product. However, discrete components are required for each of
the following actions:
the following actions:
to monitor VBUS voltage
for line termination
to disconnect the host for reduced power consumption
42.5.2 VBUS Monitoring
VBUS monitoring is required to detect host connection. VBUS monitoring is done using a standard PIO with
internal pull-up disabled. When the host is switched off, it should be considered as a disconnect, the pull-up must
be disabled in order to prevent powering the host through the pull-up resistor.
internal pull-up disabled. When the host is switched off, it should be considered as a disconnect, the pull-up must
be disabled in order to prevent powering the host through the pull-up resistor.
When the host is disconnected and the transceiver is enabled, then DDP and DDM are floating. This may lead to
over consumption. A solution is to enable the integrated pull-down by disabling the transceiver (TXVDIS = 1) and
then remove the pull-up (PUON = 0).
over consumption. A solution is to enable the integrated pull-down by disabling the transceiver (TXVDIS = 1) and
then remove the pull-up (PUON = 0).
A termination serial resistor must be connected to DDP and DDM. The resistor value is defined in the electrical
specification of the product (R
specification of the product (R
EXT
).
R
EXT
R
EXT
DDM
DDP
PIO
27 K
47 K
Type B
Connector
1
2
3
4
5V Bus Monitoring