SI3461-KIT Silicon Laboratories Inc, SI3461-KIT Datasheet - Page 27

• Manufacturer Part Number: SI3461-KIT
• Description: BOARD EVAL FOR SI3461
• Manufacturer: Silicon Laboratories Inc
• Type: Controllers & Processorsr

Specifications of SI3461-KIT

• Main Purpose: Special Purpose DC/DC, Power Over Ethernet
• Board Type: Fully Populated
• Utilized Ic / Part: Si3461
• Ethernet Connection Type: 10/100 Base-T, IEEE 802.3
• Interface Type: Ethernet
• Operating Voltage: 12 V to 15 V
• Operating Current: 10 mA
• Product: Modules
• For Use With/related Products: Si3460
• Lead Free Status / RoHS Status: Lead free / RoHS non-compliant
• Current - Output: -
• Voltage - Output: -
• Voltage - Input: -
• Power - Output: -
• Frequency - Switching: -
• Outputs And Type: -
• Regulator Topology: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 336-1843

Si3461-EVB
13. Operating the Si3461-EVB
The Si3461-EVB itself is very simple to use. Only a 50 V dc power source is needed for connection to J2. A power
rating of at least 35 W is recommended when the high-power PoE+ mode is used.
The Si3461 will automatically power up, detect the operational modes (midspan/endpoint, classification power
level, and restart mode), and begin the detection process, during which the LED flashes at 1.5 times per second.
Figure 22. Si3461-EVB
To test the Si3461-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
Si3461-EVB to receive PSE power while exchanging Ethernet traffic. One example of a POE+ PD is an 802.11n
(multi-radio) wireless access point.
To test the Si3461-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
Si3461-EVB to receive PSE power while exchanging Ethernet traffic.
Another PD option is to use the Si3461-EVB with one of the Si3400/01 or Si3402 evaluation boards configured to
present a Class 4 load if POE+ is desired. If one of these boards is used, it 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 Si3461 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. The flashing will continue for 2.2
seconds or until an open circuit is detected as determined by the operating mode of the Si3461.
The Si3461 mode is set by the voltage levels provided by resistors R100 through R103 and DIP switch SW2
according to Table 2 on page 7. Note that each resistor should be connected to either the 3.3 V supply rail or to
ground in order to generate correct voltages (i.e. the two corresponding switches should be in opposite positions).
Odd-numbered switches connect the resistors to the 3.3 V supply, and even-numbered switches connect them to
ground. The MSB is controlled by switches 1 and 2. After changing the settings, push the reset button for the new
mode to take effect.
The reference board is shipped configured for midspan power injection with full power support and automatic retry
after a fault (DIP switch setting 01101010).
Rev. 0.5
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