MAX5982CETE+ Maxim Integrated Products, MAX5982CETE+ Datasheet - Page 13

• Manufacturer Part Number: MAX5982CETE+
• Description: Power Switch ICs - POE / LAN PDIC, up to 70W
• Manufacturer: Maxim Integrated Products

Specifications of MAX5982CETE+

• Lead Free Status / Rohs Status: Details

Alternatively, the 2EC output also serves as a wall adapt-
er detection output when the MAX5982A/MAX5982B/
MAX5982C are powered by an external wall power
adapter. See the Wall Power Adapter Detection and
Operation section for more information.
The MAX5982A/MAX5982B/MAX5982C enter power
mode when V
out threshold (V
MAX5982A/MAX5982B/MAX5982C turn on the internal
n-channel isolation MOSFET to connect V
inrush current limit internally set to 53mA when V
V
tion MOSFET is fully turned on when the voltage at RTN
is near V
inrush limit. Once the isolation MOSFET is fully turned
on, the MAX5982A/MAX5982B/MAX5982C change the
current limit to 1900mA (typ). The open-drain power-
good output (PG) remains low for a minimum of t
until the power MOSFET fully turns on to keep the down-
stream DC-DC converter disabled during inrush.
The MAX5982A/MAX5982B/MAX5982C operate up to a
60V supply voltage with a turn-on UVLO threshold (V
at 35.4V and a turn-off UVLO threshold (V
When the input voltage is above V
MAX5982B/MAX5982C enter power mode and the inter-
nal MOSFET is turned on. When the input voltage goes
below V
The MAX5982A/MAX5982B feature a sleep mode, which
pulls PG low while keeping the internal n-channel isola-
tion MOSFET turned on. The PG output is used to dis-
able downstream DC-DC converters reducing the power
consumption of the overall PD system in sleep mode. In
sleep mode, the LED driver output (LED) sources peri-
odic current pulses. The LED current (I
external resistor (R
section for more information. To enable sleep mode,
apply a falling edge to SL (MAX5982B) or hold SL low for
a minimum of 6 seconds after a falling edge.
An ultra-low-power sleep mode allows the MAX5982A/
MAX5982B to further reduce power consumption while
maintaining the power signature of the standard. The
ultra-low-power sleep enable input ULP is internally
held high with a 50kΩ pullup resistor to the internal 5V
bias of the MAX5982A/MAX5982B. To enable ultra-low-
power sleep sleep mode, set ULP to logic-low and apply
a falling edge to SL (MAX5982B) or hold SL low for a
Controllers with
IEEE 802.3af/at-Compliant, Powered Device Interface
SS
> 7V and 135mA when V
OFF
SS
for more than t
and the inrush current is reduced below the
IN
ON
______________________________________________________________________________________
Sleep Modes (MAX5982A/MAX5982B)
rises above the undervoltage-lock-
SL
). When V
); see the Applications Information
OFF_DLY
Sleep and Ultra-Low-Power
Undervoltage Lockout
Power Mode (Wake Mode)
RTN
IN
rises above V
, the MOSFET turns off.
- V
ON
SS
Integrated 70W High-Power MOSFET
, the MAX5982A/
LED
< 7V. The isola-
SS
) is set by an
OFF
to RTN with
) at 31V.
ON
DELAY
RTN
, the
ON
-
)
minimum of 6s (MAX5982A). Apply a falling edge on the
wake-mode enable input (WK) to disable sleep or ultra-
low-power sleep mode and resume normal operation.
The MAX5982A/MAX5982B drive an LED connected
from the output LED to V
power sleep mode, the LED is driven by current pulses
with the amplitude set by the resistor connected from SL
to V
mable from 10mA to 20mA using R
following formula:
An open-drain output (PG) is used to allow disabling
downstream DC-DC converter until the n-channel isola-
tion MOSFET is fully turned on. PG is pulled low to V
for a period of t
MOSFET is fully turned on. The PG is also pulled low
during sleep mode and coming out of thermal shutdown.
The MAX5982A/MAX5982B/MAX5982C include thermal
protection from excessive heating. If the junction tempera-
ture exceeds the thermal-shutdown threshold of +150NC,
the MAX5982A/MAX5982B/MAX5982C turn off the internal
power MOSFET, LED driver, and 2EC current sink. When
the junction temperature falls below +120NC, the devices
enter inrush mode and then return to power mode. Inrush
mode ensures the downstream DC-DC converter is turned
off as the internal power MOSFET is turned on.
For applications where an auxiliary power source such
as a wall power adapter is used to power the PD,
the MAX5982A/MAX5982B/MAX5982C feature wall
power adapter detection. The MAX5982A/MAX5982B/
MAX5982C give highest priority to the WAD and smooth-
ly switch the power supply to WAD when it is detected.
Once the input voltage (V
event threshold, the MAX5982A/MAX5982B/MAX5982C
enable wall adapter detection. The wall power adapt-
er is connected from WAD to RTN. The MAX5982A/
MAX5982B/MAX5982C detect the wall power adapter
when the voltage from WAD to RTN is greater than 9V.
When a wall power adapter is detected, the internal
n-channel isolation MOSFET turns off, 2EC current sink
turns on, and classification current is disabled if V
the classification range.
Wall Power Adapter Detection and Operation
SS
. The LED driver current amplitude is program-
I
LED Driver ( MAX5982A/MAX5982B )
LED
DELAY
=
Thermal-Shutdown Protection
R
SL
645.75
SS
+
and until the internal isolation
1200
. During sleep mode/ultra-low-
DD
- V
(in amperes)
Power-Good Output
SS
) exceeds the mark
SL
according to the
IN
is in
13
SS