Rainbow Electronics MAX5945 - Manual (Page 4)

MAX5945
Quad Network Power Controller
for Power-Over-LAN
4 _______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS (continued)
(AGND = +32V to +60V, V EE = 0V, V DD to DGND = +3.3V, all voltages are referenced to V EE , unless otherwise noted. Typical
values are at AGND = +48V, DGND = +48V, V DD = (DGND + 3.3V), T A = +25°C. Currents are positive when entering the pin and
negative otherwise.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
AC Load Disconnect
Threshold (Note 4)
I ACTH
Current into DET_, ACD_EN_ bit = high,
OSC_IN = 2.2V
300 325 350 µA
Oscillator Buffer Gain A OSC
V DET_ / V OSC_IN , ACD_EN_ bit = high,
C DET = 400nF
2.92 2.98 3.04 V/V
OSC_IN Fail Threshold
(Note 5)
V OS C _F AI L
Port will not power on if V OSC_IN < V OSC_FAIL and
ACD_EN_ bit = high
1.8 1.9 2.1 V
OSC_IN Input Resistance Z OSC
OSC_IN input impedance when all the ACD_EN_
are active
100 k Ω
OSC_IN Input Capacitance C OSC_IN 5 pF
Load Disconnect Timer t
DISC
Time from V SENSE < V DCTH or current into DET_
< I ACTH to gate shutdown (Note 6)
300 400 ms
DETECTION
Detection Probe Voltage
(First Phase)
V DPH1 V AGND - V DET_ during the first detection phase 3.8 4 4.2 V
Detection Probe Voltage
(Second Phase)
V DPH2
V AGND - V DET_ during the second detection
phase
9.0 9.3 9.6 V
Current-Limit Protection I DLIM
V DET_ = V AGND , during detection, measure
current through DET_
1.5 1.75 2.0 mA
Short-Circuit Threshold V DCP
If V A GN D - V OU T < V D C P after the fi r st d etecti on
p hase a shor t ci r cui t to AG N D i s d etected
1.62 V
Open-Circuit Threshold I D_OPEN
First point measurement current threshold for
open condition
12.5 µA
Resistor Detection Window R DOK (Note 7) 18.6 26.5 k Ω
Detection rejects lower values 16
Resistor Rejection Window R DBAD
Detection rejects higher values 30
k Ω
CLASSIFICATION
Classification Probe Voltage V CL V AGND - V DET_ during classification 16 20 V
Current-Limit Protection I ClLIM
V DET_ = V AGND , during classification,
measure current through DET_
50 75 mA
Class 0, class 1 5.5 6.5 7.5
Class 1, class 2 13.5 14.5 15.5
Class 2, class 3 21.5 23 24.5
Class 3, class 4 31 33 35
Classification Current
Thresholds
I CL
Classification current
thresholds between
classes
>Class 4 45 48 51
mA
DIGITAL INPUTS/OUTPUTS (REFERRED to DGND)
Digital Input Low V
IL
0.9 V
Digital Input High V IH 2.4 V