Datasheet

LTC4267-1
3
42671fa
For more information www.linear.com/4267-1
elecTrical characTerisTics
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. (Note 3)
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
PORTN
Supply Voltage
Maximum Operating Voltage
Signature Range
Classification Range
UVLO Turn-On Voltage
UVLO Turn-Off Voltage
Voltage with Respect to V
PORTP
Pin
(Notes 4, 5, 6)
l
l
l
l
l
–1.5
–12.5
–34.8
–29.3
–36.0
–30.5
–57
–9.5
–21
–37.2
–31.5
V
V
V
V
V
V
TURNON
P
VCC
Turn-On Voltage Voltage with Respect to PGND
l
7.8 8.7 9.2 V
V
TURNOFF
P
VCC
Turn-Off Voltage Voltage with Respect to PGND
l
4.6 5.7 6.8 V
V
HYST
P
VCC
Hysteresis V
TURNON
– V
TURNOFF
l
1.5 3.0 V
V
CLAMP1mA
P
VCC
Shunt Regulator Voltage I
PVCC
= 1mA, V
ITH
/RUN = 0V,
Voltage with Respect to PGND
l
8.3 9.4 10.3 V
V
MARGIN
V
CLAMP1mA
– V
TURNON
Margin
l
0.05 0.6 V
I
VPORTN_ON
V
PORTP
Supply Current when ON V
PORTN
= –48V, P
OUT
, PWRGD, SIGDISA Floating
l
3 mA
I
PVCC_ON
PVCC Supply Current
Normal Operation
Start-Up
(Note 7)
V
ITH
/RUN – PGND = 1.3V
P
VCC
– PGND = V
TURNON
– 100mV
l
l
240
40
350
90
µA
µA
I
VPORTN_CLASS
V
PORTN
Supply Current During
Classification
V
PORTN
= –17.5V, P
OUT
Tied to V
PORTP
, R
CLASS
,
SIGDISA Floating (Note 8)
l
0.35 0.5 0.65 mA
ΔI
CLASS
Current Accuracy During Classification 10mA < I
CLASS
< 40mA, –12.5V ≤ V
PORTN
≤ –21V
(Note 9)
l
±3.5 %
R
SIGNATURE
Signature Resistance –1.5V ≤ V
PORTN
≤ – 9.5V, P
OUT
Tied to V
PORTP
,
IEEE 802.3af 2-Point Measurement (Notes 4, 5)
l
23.25 26.00 kΩ
R
INVALID
Invalid Signature Resistance –1.5V ≤ V
PORTN
≤ –9.5V, SIGDISA and P
OUT
Tied to
V
PORTP
, IEEE 802.3af 2-Point Measurement
(Notes 4, 5)
l
9 11.8 kΩ
V
IH
Signature Disable
High Level Input Voltage
With Respect to V
PORTN
High Level Invalidates Signature (Note 10)
l
3 57 V
V
IL
Signature Disable
Low Level Input Voltage
With Respect to V
PORTN
Low Level Enables Signature
l
0.45 V
R
INPUT
Signature Disable, Input Resistance With Respect to V
PORTN
l
100 kΩ
V
PG_OUT
Power Good Output Low Voltage I = 1mA V
PORTN
= –48V,
PWRGD Referenced to V
PORTN
l
0.5 V
V
PG _FALL
V
PG_RISE
Power Good Trip Point V
PORTN
= –48V, Voltage between V
PORTN
and P
OUT
P
OUT
Falling
P
OUT
Rising
l
l
1.3
2.7
1.5
3.0
1.7
3.3
V
V
I
PG_LEAK
Power Good Leakage Current V
PORTN
= 0V, PWRGD FET Off, V
PWRGD
= 57V
l
1 µA
R
ON
On-Resistance I = 300mA, V
PORTN
= –48V, Measured from
V
PORTN
to P
OUT
l
1.0 1.6
2
Ω
Ω
V
ITHSHDN
Shutdown Threshold (at I
TH
/RUN) P
VCC
– PGND = V
TURNON
+ 100mV
l
0.15 0.28 0.45 V
I
THSTART
Start-Up Current Source at I
TH
/RUN V
ITH
/RUN – PGND = 0V, P
VCC
– PGND = 8V 0.2 0.3 0.4 µA
V
FB
Regulated Feedback Voltage Referenced to PGND, P
VCC
– PGND = 8V (Note 11)
l
0.780 0.800 0.812 V
I
FB
V
FB
Input Current P
VCC
– PGND = 8V (Note 11) 10 50 nA
g
m
Error Amplifier Transconductance I
TH
/RUN Pin Load = ±5µA (Note 11) 200 333 500 µA/V
ΔV
O(LINE)
Output Voltage Line Regulation V
TURNOFF
< P
VCC
< V
CLAMP
(Note 11) 0.05 mV/V
ΔV
O(LOAD)
Output Voltage Load Regulation I
TH
/RUN Sinking 5µA, P
VCC
– PGND = 8V (Note 11)
I
TH
/RUN Sourcing 5µA, P
VCC
– PGND = 8V (Note 11)
3
3
mV/µA
mV/µA
I
POUT_LEAK
P
OUT
Leakage V
PORTN
= 0V, Power MOSFET Off,
P
OUT
= 57V (Note 12)
l
150 µA