Linear Technology LTC4257CS8-1, Power-Over-Ethernet Interface Controller, Vsig = 48V, Vout = 3.3V DC671A DC671A Data Sheet
Product codes
DC671A
LTC4257-1
2
42571fb
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
V
IN
Supply Voltage
Voltage with Respect to GND Pin (Notes 4, 5, 6)
Maximum Operating Voltage
●
– 57
V
Signature Range
●
– 1.5
– 9.5
V
Classification Range
●
– 12.5
– 21
V
UVLO Turn-On Voltage
●
– 34.8
–36.0
– 37.2
V
UVLO Turn-Off Voltage
●
– 29.3
–30.5
– 31.5
V
I
IN_ON
IC Supply Current when ON
V
IN
= – 48V, Pins 5, 6, 7 Floating
●
3
mA
I
IN_CLASS
IC Supply Current During Classification V
IN
= – 17.5V, Pins 2, 7 Floating, V
OUT
Tied to GND
●
0.35
0.50
0.65
mA
(Note 7)
∆I
CLASS
Current Accuracy During Classification 10mA < I
CLASS
< 40mA, – 12.5V
≤ V
IN
≤ –21V,
●
±3.5
%
(Notes 8, 9)
R
SIGNATURE
Signature Resistance
–1.5V
≤ V
IN
≤ –9.5V, V
OUT
Tied to GND,
●
23.25
26.00
k
Ω
IEEE 802.3af 2-Point Measurement (Notes 4, 5)
R
INVALID
Invalid Signature Resistance
– 1.5V
≤ V
IN
≤ –9.5V, SIGDISA and V
OUT
●
9
11.8
k
Ω
Tied to GND, IEEE 802.3af 2-Point Measurement
(Notes 4, 5)
(Notes 4, 5)
(Notes 1, 2)
V
IN
Voltage ............................................. 0.3V to – 100V
V
OUT
, SIGDISA,
PWRGD Voltage ...................... V
IN
+ 100V to V
IN
– 0.3V
R
CLASS
Voltage ............................ V
IN
+ 7V to V
IN
– 0.3V
PWRGD Current .................................................. 10mA
R
R
CLASS
Current .................................................. 100mA
The
●
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25
°C. (Note 3)
ABSOLUTE AXI U RATI GS
W
W
W
U
ELECTRICAL CHARACTERISTICS
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grades are identified by a label on the shipping container.
PACKAGE/ORDER I FOR ATIO
U
U
W
Operating Ambient Temperature Range
LTC4257C-1 ............................................ 0
°C to 70°C
LTC4257I-1 ......................................... –40
°C to 85°C
Storage Temperature Range
S8 Package ....................................... – 65
°C to 150°C
DD Package ...................................... – 65
°C to 125°C
Lead Temperature (Soldering, 10 sec).................. 300
°C
ORDER PART NUMBER
1
2
3
4
8
7
6
5
TOP VIEW
GND
SIGDISA
PWRGD
V
OUT
NC
R
CLASS
NC
V
IN
S8 PACKAGE
8-LEAD PLASTIC SO
T
JMAX
= 150
°C, θ
JA
= 150
°C/W
TOP VIEW
DD PACKAGE
8-LEAD (3mm
× 3mm) PLASTIC DFN
5
6
7
8
4
3
2
1
NC
R
CLASS
NC
V
IN
GND
SIGDISA
PWRGD
V
OUT
T
JMAX
= 125
°C, θ
JA
= 43
°C/W
EXPOSED PAD TO BE SOLDERED TO ELECTRICALLY ISOLATED PCB HEATSINK
S8 PART MARKING
42571
4257I1
4257I1
LTC4257CS8-1
LTC4257IS8-1
LTC4257IS8-1
ORDER PART NUMBER
DD PART MARKING*
LBFZ
LTC4257CDD-1
LTC4257IDD-1
LTC4257IDD-1
Order Options Tape and Reel: Add #TR Lead Free: Add #PBF
Lead Free Tape and Reel: Add #TRPBF Lead Free Part Marking:
Lead Free Tape and Reel: Add #TRPBF Lead Free Part Marking: