MAX5940A/MAX5940B
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........................................................................-0.3V to +80V
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 µA
Effective Differential Input
Resistance (Note 3) dR VIN = 1.4V up to 10.1V with 1V step,
OUT = PGOOD = GND 550 kΩ
CLASSIFICATION MODE
Classification Current Turn-Off
Threshold (Note 4) VTH
CLSS VIN rising 20.8 21.8 22.5 V
Class 0, RCL = 10kΩ02
Class 1, RCL = 732Ω9.17 11.83
Class 2, RCL = 392Ω17.29 19.71
Class 3, RCL = 255Ω26.45 29.55
Classification Current (Notes 5, 6) ICLASS
VIN = 12.6V to
20V, RDISC =
25.5kΩ
Class 4, RCL = 178Ω36.6 41.4
mA
POWER MODE
Operating Supply Voltage VIN VIN = (GND - VEE)67V
Operating Supply Current IIN Measure at GND, not including RDISC 0.4 1 mA
MAX5940A 34.3 35.4 36.6
Default Power Turn-On Voltage VUVLO
ON VIN increasing MAX5940B, UVLO = VEE 37.4 38.6 39.9 V
Default Power Turn-Off Voltage VUVLO
OFF VIN decreasing, UVLO = VEE for
MAX5940B 30 V
MAX5940A 4.2
Default Power Turn-On/Off
Hysteresis
VHYST,
UVLO MAX5940B, UVLO = VEE 7.4 V
External UVLO Programming
Range VIN,EX Set UVLO externally (MAX5940B 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 µA