SI3453-B01-GM Silicon Laboratories Inc, SI3453-B01-GM Datasheet - Page 18

• Manufacturer Part Number: SI3453-B01-GM
• Description: IC POE CONTROLLER MIDSPAN 40QFN
• Manufacturer: Silicon Laboratories Inc

Specifications of SI3453-B01-GM

• Package / Case: 40-QFN
• Controller Type: Power over Ethernet Controller (POE)
• Interface: I²C
• Voltage - Supply: 3 V ~ 3.6 V
• Current - Supply: 14mA
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Maximum Power Dissipation: 1.2 W
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Product: Ethernet Controllers
• Standard Supported: IEEE 802.3at, IEEE 802.3af
• Supply Voltage (max): 3.6 V
• Supply Voltage (min): 3 V
• Supply Current (max): 14 mA
• Maximum Operating Temperature: + 85 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: 336-1837-5

Si3452/3
“DET compl“ indicates the completion of a detection cycle. Normally this bit will be masked. The DET complete bit
would be used for legacy detection via modified link pulses. If the link pulse is returned indicating a PD is present
then normally a detection is done and the port is powered only if the result is not a short. In some cases it may be
desirable to deny power to a port where an overload has been detected until the port is unplugged. In this case, the
Ropen result will be used to indicate the port has been unplugged and detection and classification can resume.
“Disconnect event“ indicates a disconnect has occurred. DC power was removed due to the dV/dt™ or DC
disconnect. Overload conditions or loss of V
“Pgood“ indicates the port has been turned on and did not shut down during the Tstart time.
“Penable“ indicates a port has been turned on.
5.3. Port Status (Registers 0x06–0x09)
These registers specify the port status. They are read only.
“Pwr good“ indicates the port has been turned on, and the port voltage is within 2 V of V
“Pwr Enable“ indicates the port has been turned on.
The 3 class status bits indicate the last classification result for that port. If a classification has not been done or if
the port is shutdown with no new classification result, the class status is reported as unknown.
The 3 detect status bits indicate the last detection result for that port. If a detection has not been done or if the port
is shutdown with no new detection result, the detection status is reported as unknown.
5.4. Port Configuration (Registers 0x0A–0x011)
These registers indicate the port configuration. They are read/write.
The “PoE+“ bit specifies the dc current limit at either 425 mA or 850 mA nominal.
“Disconnect enable“ must be set for power to be removed if there is a disconnect. The disconnect type (based on
dc disconnect or based on Silicon Laboratories proprietary dV/dt disconnect) is determined by the ordering part
number.
“Port mode“ is set according to the following table.
I
can be set with 3.2 mA resolution. The accuracy of current measurement is approximately 5% so I
set 7% higher than the supported current level. I
PoE+ mode. The automatically set I
0–3 and for a 50 V minimum power supply for PoE+ mode.
If the Si3452/3 is in the semi-auto mode, I
that if it is desired to set I
18
CUT
Port Mode Setting
is the nominal current level at which the port will automatically power down if I
B1, B0
00b
01b
10b
11b
CUT
Shutdown
Semiauto
Manual
at port turn on, this should be done before the port is turned on.
Mode
Auto
CUT
Table 16. Port Mode Selection
level is appropriate for a 44 V minimum system power supply for classes
CUT
The power is shutdown with no detection pulses. A command to
manually power the port is ignored.
The port can be powered by the manual power command.
Detection is done and classification is done for Rgood but the port
does not power.
Detection Classification and Port powering are all automatic with no
host intervention required. I
according to the PoE+ mode and classification result.
EE
will not be updated according to the classification result. This means
turns off ports but does not generate a disconnect event.
CUT
Rev. 0.42
is automatically set based on the classification result and
CUT
Description
and I
LIM
CUT
are automatically set
is exceeded for 60 msec. It
EE
.
CUT
is normally