Datasheet

LTC4278
3
4278fc
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C.
PARAMETER CONDITIONS MIN TYP MAX UNITS
Interface Controller (Note 4)
Operating Input Voltage
Signature Range
Classification Range
ON Voltage
OFF Voltage
Overvoltage Lockout
At V
PORTP
(Note 5)
l
l
l
l
1.5
12.5
30.0
71
60
9.8
21
37.2
V
V
V
V
V
V
ON/OFF Hysteresis Window
l
4.1 V
Signature/Class Hysteresis Window
l
1.4 V
Reset Threshold State Machine Reset for 2-Event Classification
l
2.57 5.40 V
Supply Current
Supply Current at 57V Measured at V
PORTP
Pin
l
1.35 mA
Class 0 Current V
PORTP
= 17.5V, No R
CLASS
Resistor
l
0.40 mA
Signature
Signature Resistance 1.5V ≤ V
PORTP
≤ 9.8V (Note 6)
l
23.25 26 kΩ
Invalid Signature Resistance, SHDN Invoked 1.5V ≤ V
PORTP
≤ 9.8V, V
SHDN
= 3V (Note 6)
l
11 kΩ
Invalid Signature Resistance During Mark
Event
(Notes 6, 7)
l
11 kΩ
Classification
Class Accuracy 10mA < I
CLASS
< 40mA, 12.5V < V
PORTP
< 21V
(Notes 8, 9)
l
±3.5 %
Classification Stability Time V
PORTP
Pin Step to 17.5V, R
CLASS
= 30.9, I
CLASS
Within 3.5%
of Ideal Value (Notes 8, 9)
l
1 ms
Normal Operation
Inrush Current V
PORTP
= 54V, V
NEG
= 3V
l
60 100 180 mA
Power FET On-Resistance Tested at 600mA into V
NEG
, V
PORTP
= 54V
l
0.7 1.0 Ω
Power FET Leakage Current at V
NEG
V
PORTP
= SHDN = V
NEG
= 57V
l
1 µA
Digital Interface
SHDN Input High Level Voltage
l
3 V
SHDN Input Low Level Voltage
l
0.45 V
SHDN Input Resistance V
PORTP
= 9.8V, SHDN = 9.65V
l
100 kΩ
PWRGD, T2P Output Low Voltage Tested at 1mA, V
PORTP
= 54V. For T2P, Must Complete
2-Event Classification to See Active Low
l
0.15 V
PWRGD, T2P Leakage Current Pin Voltage Pulled 57V, V
PORTP
= V
PORTN
= 0V
l
1 µA
PWRGD Output Low Voltage Tested at 0.5mA, V
PORTP
= 52V, V
NEG
= 48V, Output Voltage
Is With Respect to V
NEG
l
0.4 V
PWRGD Clamp Voltage Tested at 2mA, V
NEG
= 0V, Voltage With Respect to V
NEG
l
12 16.5 V
PWRGD Leakage Current V
PWRGD
= 11V, V
NEG
= 0V, Voltage With Respect to V
NEG
l
1 µA