MAX5971BETI+ Maxim Integrated Products, MAX5971BETI+ Datasheet - Page 34

• Manufacturer Part Number: MAX5971BETI+
• Description: Hot Swap & Power Distribution IEEE 802.3af/at PSE Controller
• Manufacturer: Maxim Integrated Products

Specifications of MAX5971BETI+

• Lead Free Status / Rohs Status: Details

Single-Port, 40W, IEEE 802.3af/at,
PSE Controller with I
Table 24. Timer Values for Timing Register
Table 25. Miscellaneous Configurations 1 Register
The miscellaneous configuration 1 register (R17h, Table
25) is used for several functions that do not cleanly fit
within one of the other configuration categories. On a
power-up or after a reset condition, this register is set to
a default value of 0xC0h. Therefore, by default, INT_EN
(R17h[7]) and RSTR_EN (R17h[6]) are set to 1, enabling
both INT functionality and the autorestart protection timer.
Setting CL_DISC (R17h[2] to 1 enables current-limit
programming regardless of the classification result
through the ICUT[2:0] register (R2Ah). Setting OUT_ISO
(R17h[1]) to 1, forces DET to a high-impedance state.
Setting HP_TIME high enables the higher current limits
needed for type 2 PDs even during startup (during the
time after port power-up but before t
Register R18h is at this time reserved. Writing to this
register has no effect (the address autoincrement still
updates) and any attempt to read this register returns
all zeros.
34
RSTR_EN
SYMBOL
Reserved
Reserved
Reserved
OUT_ISO
CL_DISC
HP_TIME
INT_EN
(ADDRESS = 16h)
_____________________________________________________________________________________
Miscellaneous Configuration 1 Register (R17h)
ADDRESS = 17h
Pushbutton Registers (R18h to R1Ah)
BIT [1:0]
00
01
10
11
BIT NO.
7
6
5
4
3
2
1
0
TYPE
R/W
R/W
R/W
R/W
R/W
—
—
—
16 x t
32 x t
64 x t
t
0 x t
Reserved Register (R18h)
RESTART
FAULT
A logic-high enables INT functionality
A logic-high enables the autorestart protection timer (set by the RSRT[1:0] bits)
Reserved
Reserved
Reserved
A logic-high enables
the ICUT[2:0] register
A logic-high forces DET to a high-impedance state. Does not interfere with other circuit operation.
A logic-high enables the higher current limit for Type 2 PDs during startup.
FAULT
FAULT
FAULT
START
has expired).
¼ x t
½ x t
2 x t
t
DISC
(350ms, typ)
DISC
DISC
DISC
2
current-limit programming regardless of the classification result through
t
DISC
nominal
C
nominal
nominal
nominal
The power enable pushbutton register (R19h, Table
26) is used to manually power the port on or off. On a
power-up or after a reset condition, this register is set to
a default value of 0x00h. Setting PWR_ON (R19h[0]) to
1 turns on power to the port. PWR_ON commands are
ignored when the port is already powered and during
shutdown. During detection or classification, if a 1 is
written to PWR_ON, the MAX5971B gracefully terminates
the detection/classification routine and turns on power
to the port. The MAX5971B also ignores PWR_ON com-
mands when operating in auto mode. Setting PWR_OFF
(R19h[4]) to 1 turns off power to the port. PWR_OFF
commands are ignored when the port is already off and
during shutdown. After the appropriate command is
executed (port power on or off), the PWR_ON/PWR_OFF
bit resets back to 0.
The global pushbutton register (R1Ah, Table 27) is used
to manually clear interrupts and to initiate global and
port resets. On a power-up or after a reset condition, this
register is set to a default value of 0x00h. Writing a 1 to
DESCRIPTION
½ x t
2 x t
4 x t
Power Enable Pushbutton Register (R19h)
t
START
(60ms, typ)
START
START
START
t
START
Global Pushbutton Register (R1Ah)
nominal
nominal
nominal
nominal
½ x t
2 x t
4 x t
t
FAULT
(60ms, typ)
FAULT
FAULT
FAULT
t
FAULT
nominal
nominal
nominal
nominal