SI3461-KIT Silicon Laboratories Inc, SI3461-KIT Datasheet - Page 5

• 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

5. The Si3460 PSE Controller
In addition to providing a complete dc-dc controller to generate the PSE output supply, the Si3460 is a fully IEEE
compliant PSE power management controller. The Si3460 is specifically designed and configured to work with an
applications circuit (Si3460-EVB) that together implement a single port PSE solution for either midspans or
endpoints.
Referring to the detailed evaluation board schematics in Section “8. Si3460-EVB Schematics and PCB Layout”, the
overall functionality is described for each operating state of the Si3460 as follows:
5.1. Initialization and Operating Mode Configuration
The Si3460 is initialized at power up, or whenever pin 8 (RST) is held low and then allowed to transition high. Upon
reset (RST asserted), the voltage at the STATUS pin (as determined by resistors R28 and R30) is sensed to
determine the operating mode of the Si3460. The detection process begins immediately after initialization.
Any combination of the following three operating modes can be set by the R28 and R30 resistor pair, as indicated
below:



Pin voltage at VEE
3.0 V
2.75 V
2.5 V
2.25 V
2.0 V
1.75 V
1.5 V
1.25 V
1.0 V
0.5 V
< 0.25 V
Nominal Status Pin
Classification level: sets what maximum power level the Si3460 will support.
Endpoint or midspan mode: controls the backoff timing per the IEEE specifications.
Restart action on fault or overload: determines whether or not the Si3460 will automatically restart after 2 s
when a fault or overload condition (e.g., input UVLO, output short-circuit event, classification power level
exceeded) is detected, or wait to restart until the RST pin is asserted.
Voltage
2.21 k, 22.1 k
2.61 k, 8.06 k
2.94 k, 6.19 k
3.32 k, 4.99 k
3.83 k, 4.22 k
4.42 k, 3.57 k
5.36 k, 3.16 k
6.81 k, 2.80 k
2.37 k, 11.8 k
14 k, 2.26 k
R28, R30
2 k, NP
NP, 2 k
Table 2. Operating Modes
Supported (W)
Power Level
15.4
15.4
15.4
15.4
7.0
4.0
7.0
4.0
4.0
7.0
4.0
7.0
Rev. 1.1
All class levels
All class levels
All class levels
All class levels
Operating Mode
Class 1 or 2
Class 1 or 2
Class 1 or 2
Class 1 or 2
Supported
Classes
Class 1
Class 1
Class 1
Class 1
Endpoint/
Midspan
Endpoint
Midspan
Si3460-EVB
Auto restart after 2 s
Auto restart after 2 s
or when open circuit
or when open circuit
Restart on RST low
Restart on RST low
Restart Action on
Fault or Overload
detected
detected
Event
5