Si3453
24 Rev. 1.3
Table 23. Si3453 Port Configuration
PoE+ bit Class Auto Mode Setting of
I
CUT
Register
I
CUT
Nominal Ilim Nominal*
0 or 1 don’t care 1 0x1E 97 mA 425 mA
0 or 1 don’t care 2 0x35 170 mA 425 mA
0 or 1 don’t care 0/3 0x75 375 mA 425 mA
0 4 0x75 375 mA 425 mA
1 4 0xC9 640 mA 850 mA
*Note: During initial port turn-on (T
START
time of 60 ms), the current limit is set to 425 mA, even in PoE+ mode.
Table 24. Si3453 Command Codes
Command CMD Register [B5..B2]
[B1..B0] Command
Parameter
2 Byte Return Value
Power on port 0x04 | port no 0001b 2 bit port number
1
—
Power off port 0x08 | port no 0010b 2 bit port number —
Reset port 0x0C | port no 0011b 2 bit port number —
Toggle detection
back-off timing
2
0x10 0100b NA —
Reset chip 0x14 0101b NA —
Get V
EE
0x18 0110b NA V
EE
in mV units
Read port current
0x1C | port no 0111b 2 bit port number
Port current in 100 µA
units
Shut down
low-priority ports
0x20 1000b NA —
Notes:
1.
Port 1 has 2 bit port number 0x00; port 2 is 0x01, etc.
2. This command toggles bit 0 of Register 0x1D. When bit zero is set, the detection back-off of 2 seconds is implemented
(alternative B or “midspan” mode).
