Rainbow Electronics MAX5971А - Manual (Page 5)

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MAX5971A
Single-Port, 40W, IEEE 802.3af/802.3at PSE
Controller with Integrated MOSFET
Note 2: All devices are production tested at T A = +25NC. Limits at T A = -40NC and +85NC are guaranteed by design.
Note 3: If ILIM1 and ILIM2 are both unconnected, Class 5 detection is disabled. See the Class 5 PD Classification section and Table 3 for
details and settings.
Note 4: R DOK = (V OUT2 - V OUT1 )/(I DET2 - I DET1 ). V OUT1 , V OUT2 , I DET2 , and I DET1 represent the voltage at OUT and the current at
DET during phase 1 and 2 of the detection, respectively.
Note 5: If Class 5 is enabled, this is the classification current thresholds from Class 4 to Class 5.
ELECTRICAL CHARACTERISTICS (continued)
(V AGND - V EE = 32V to 60V, T A = -40NC to +85NC, all voltages are referenced to V EE , unless otherwise noted. Typical values are at
V AGND - V EE = +54V, T A = +25NC. Currents are positive when entering the pin and negative otherwise.) (Note 2)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
DIGITAL INPUTS/OUTPUTS (Voltages referenced to V EE )
Digital Input Low V IL 0.8 V
Digital Input High V IH 2.4 V
Internal Input Pullup Current I PU
Pullup current to internal digital supply to
set default values
3 5 7
F A
LED Output Low Voltage V LED_LOW I LED = 10mA, PWM disabled, port power-on 0.8 V
LED Output Leakage I LED_LEAK
PWM disabled, shutdown mode,
V
LED = 60V
10 F A
PWM Frequency 25 kHz
PWM Duty Cycle 6.25 %
TIMING
Startup Time t START
Time during which a current limit set to
420mA is allowed, starts when power is
turned on
50 60 70 ms
Fault Time t FAULT
Maximum allowed time for an overcurrent
condition set by I
CUT after startup
50 60 70 ms
Detection Reset Time t ME
Time allowed for the port voltage to reset
before detection starts
80 90 ms
Detection Time t DET
Maximum time allowed before detection is
completed
330 ms
Midspan Mode Detection Delay t DMID 2 2.2 2.4 s
Classification Time t CLASS Time allowed for classification 19 23 ms
Mark Event Time Time allowed for mark event 7 9 11 ms
V EEUVLO Turn-On Delay t DLY
Time V AGND must be above the V EEUVLO
thresholds before the device operates
5.2 ms
Restart Timer t RESTART
Time the device waits before turning on
after an overcurrent fault 16 x
t FAULT
ms