MAX5940A/MAX5940B/MAX5940C/MAX5940D
IEEE 802.3af PD Interface Controller
For Power-Over-Ethernet
2
_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VIN = (GND - VEE) = 48V, GATE = PGOOD = PGOOD = OUT = OPEN, UVLO = VEE, TA = -40
°C to +85°C, unless otherwise noted.
Typical values are at TA = +25
°C. All voltages are referenced to VEE, unless otherwise noted.) (Note 1)
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
(All voltages are referenced to VEE, unless otherwise noted.)
GND (MAX5940A/MAX5940B) ...............................-0.3V to +80V
GND (MAX5940C/MAX5940D)...............................-0.3V to +90V
OUT, PGOOD ...........................................-0.3V to (GND + 0.3V)
RCLASS, GATE ......................................................-0.3V to +12V
UVLO ........................................................................-0.3V to +8V
PGOOD to OUT.........................................-0.3V to (GND + 0.3V)
Maximum Input/Output Current (continuous)
OUT to VEE ...................................................................500mA
GND, RCLASS to VEE .....................................................70mA
UVLO, PGOOD, PGOOD to VEE .....................................20mA
GATE to VEE....................................................................80mA
Continuous Power Dissipation (TA = +70°C)
8-Pin SO (derate 5.9mW/°C above +70°C)..................470mW
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Junction Temperature ......................................................+150°C
Lead Temperature (soldering, 10s) ................................+300°C
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
DETECTION MODE
Input Offset Current (Note 2)
IOFFSET
VIN = 1.4V to 10.1V
10
A
Effective Differential Input
Resistance (Note 3)
dR
VIN = 1.4V up to 10.1V with 1V step,
OUT = PGOOD = GND
550
k
Ω
CLASSIFICATION MODE
Classification Current Turn-Off
Threshold (Note 4)
VTH,CLSS
VIN rising
20.8
21.8
22.5
V
Class 0, RCL = 10k
Ω
02
Class 1, RCL = 732
Ω
9.17
11.83
Class 2, RCL = 392
Ω
17.29
19.71
Class 3, RCL = 255
Ω
26.45
29.55
Classification Current (Notes 5, 6)
ICLASS
VIN = 12.6V to
20V, RDISC =
25.5k
Ω
Class 4, RCL = 178
Ω
36.6
41.4
mA
POWER MODE
Operating Supply Voltage
VIN
VIN = (GND - VEE)67
V
Operating Supply Current
IIN
Measure at GND, not including RDISC
0.4
1
mA
MAX5940A/MAX5940C
34.3
35.4
36.6
Default Power Turn-On Voltage
VUVLO, ON
VIN increasing
MAX5940B/MAX5940D,
UVLO = VEE
37.4
38.6
39.9
V
Default Power Turn-Off Voltage
VUVLO, OFF
VIN decreasing, UVLO = VEE for
MAX5940B/MAX5940D
30
V
MAX5940A/MAX5940C
4.2
Default Power Turn-On/Off
Hysteresis
VHYST,
UVLO
MAX5940B/MAX5940D, UVLO = VEE
7.4
V
External UVLO Programming
Range
VIN,EX
Set UVLO externally (MAX5940B/
MAX5940D only) (Note 7)
12
67
V
UVLO External Reference Voltage
VREF, UVLO
2.400
2.460
2.522
V
UVLO External Reference Voltage
Hysteresis
HYST
Ratio to VREF,UVLO
19.2
20
20.9
%
UVLO Bias Current
IUVLO
UVLO = 2.460V
-1.5
+1.5
A