MAX5945EAX+ Maxim Integrated Products, MAX5945EAX+ Datasheet - Page 32

• Manufacturer Part Number: MAX5945EAX+
• Description: IC NETWORK PWR CTRL 36-SSOP
• Manufacturer: Maxim Integrated Products

Specifications of MAX5945EAX+

• Controller Type: Network Power Controller
• Interface: I²C
• Voltage - Supply: 3.3V
• Current - Supply: 4.2mA
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 36-SSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Quad Network Power Controller
for Power-Over-LAN
the bits in register R12h to 00. A high in HWMODE_
switches the port into auto mode by setting the bits in
register R12h to 11. If WD_INT_EN is set, an interrupt is
sent if any of the SMODE bits are set.
A reset sets R1Fh = 00h.
Use IGATE[2:0] (Table 27) to set the gate pin pullup
current, I
where N is the decimal value of IGATE[2:0].
Use AC_TH[2:0] to program the current threshold of the
AC disconnect comparator according to the following
formula:
where N is the decimal value of AC_TH[2:0].
Note: The programmed value has the same percent-
age tolerance as the value specified in the Electrical
Characteristics.
When set low, DET_BYP inhibits port power-on if the
discovery detection was bypassed in AUTO mode.
Table 25. Watchdog Timer Register
Table 26. Switch Mode Register
32
EN_WHDOG
WD_INT_EN
SYMBOL
HWMODE4
HWMODE3
HWMODE2
HWMODE1
WDTIME
SYMBOL
Reserved
Reserved
______________________________________________________________________________________
ADDRESS = 1Fh
ADDRESS = 1Eh
PU
IAC_TH = 213.68µA + 28.33µA x N
, according to the following formula:
BIT
7
6
5
4
3
2
1
0
BIT
7
6
5
4
3
2
1
0
I
PU
= 50µA - 6.25 x N
R/W
R/W
R/W
R/W
R/W
R/W
R/W
—
—
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
A logic high enables the watchdog function
Enables interrupt on SMODE_ bits
Port 4 switches to AUTO if logic high and to SHUTDOWN if logic low when watchdog timer expires
Port 3 switches to AUTO if logic high and to SHUTDOWN if logic low when watchdog timer expires
Port 2 switches to AUTO if logic high and to SHUTDOWN if logic low when watchdog timer expires
Port 1 switches to AUTO if logic high and to SHUTDOWN if logic low when watchdog timer expires
WDTIME[7]
WDTIME[6]
WDTIME[5]
WDTIME[4]
WDTIME[3]
WDTIME[2]
WDTIME[1]
WDTIME[0]
When set high, it allows the part to turn on power to a
non-IEEE 802.3af load without doing detection. If
OSCF_RS is set high, the OSC_FAIL bit is ignored.
A reset sets R23h = 04h, which sets I
I
Characteristics.
Use R27h (Table 28) to program the current-limit
threshold, V
detection time, t
Use IMAX[3:0] to program the current-limit trip voltage
according to the following formula:
where N is the decimal value of IMAX[3:0]. The
V
value (I
A reset sets R27h = 47h, which sets V
(typical) as shown in the Electrical Characteristics. The
default threshold is set to meet the IEEE 802.3af stan-
dard when using an R
AC_TH
FAULT_LIM
DESCRIPTION
DESCRIPTION
FAULT
= 325µA as shown in the Electrical
V
SU_LIM
SU_LIM
limit scales proportionally to the V
= 88% of V
DISC
, and the nominal load disconnect
= 135mV + 19.25mV x N
nominal.
SENSE
SU_LIM
= 0.5Ω ±1%, 100ppm.
).
SU_LIM
PU
= 50µA and
= 212mV
SU_LIM