Si3460-EVB
Rev. 1.2
23
Not Recom
m
en
ded
for N
ew D
esigns.
Please Co
ns
id
er Si3462 for
N
ew
D
esigns.
11. Operating the Si3460-EVB
The Si3460-EVB itself is very simple to use. Only a basic 12 or 15 V dc power source (i.e., a wall wart) with at least
an 18 W rating is needed for connection to J4. The Si3460 will automatically power up, detect the operational
modes (midspan/endpoint, classification power level, and restart mode), and then begin the detection process,
during which the LED flashes at 3 times per second.
Figure 17. Si3460-EVB
To test the Si3460-EVB in a PoE environment, many commercial PDs are available, such as Wireless Access
Points (WAPs), Voice over IP phones (VoIP), and IP-based security cameras. Any of these can be connected to the
Si3460-EVB to receive PSE power while exchanging Ethernet traffic.
Another PD option is to use the Si3460-EVB with one of the Si3400/01 evaluation boards. If a Si3400 EVB is used
with the Si3460-EVB, the S3400 EVB should be configured to present a minimum load of > 0.25 W to ensure that it
draws at least 10 mA to comply with the IEEE standard.
When the Si3460 is applying power to a valid PD, the LED is continuously lit. After an error condition (e.g., an
UVLO or short-circuit event) is detected, the LED flashes at 10 times per second, or until a reset is asserted, or
when an open circuit is detected as determined by the operating mode of the Si3460.
Resistors R23, R25, and the programming header J6 are used for development purposes only. The Si3460 is not
user programmable, and it is not recommended these components be included in actual layouts (short R23 and
R25, and remove J6).
The Si3460 mode is set by resistors R28 and R30. Placeholder values of 10 k
are shown in the schematics. To
keep the voltage level at the transistor base accurate, it is recommended that the parallel resistor combination
setting the pin voltage be less than 2 k
. It is expected that most applications will support full power in either a
midspan or endpoint application and enable automatic reset after an overload.
The reference board is shipped configured for midspan power injection with full power support and automatic retry
after a fault. Resistors R28 and R30 may be replaced to support other modes of operation. See Section "5.1.
Initialization and Operating Mode Configuration" on page 5 for more information.
