LTC4257 Datasheet, PDF (2/20 Pages) Linear Technology – IEEE 802.3af PD Power over Ethernet Interface Controller

LTC4257
ABSOLUTE AXI U RATI GS
(Notes 1, 2)
V_IN Voltage ............................................. 0.3V to – 100V
V_OUT, 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_CLASS Current .................................................. 100mA
UW U
PACKAGE/ORDER I FOR ATIO
Operating Ambient Temperature Range
LTC4257C ............................................... 0°C to 70°C
LTC4257I ............................................. –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
TOP VIEW
NC 1
R_CLASS 2
NC 3
V_IN 4
8 GND
7 NC
6 PWRGD
5 V_OUT
S8 PACKAGE
8-LEAD PLASTIC SO
T_JMAX = 150°C, θ_JA = 150°C/W
TOP VIEW
NC 1
R_CLASS 2
NC 3
V_IN 4
8 GND
7 NC
6 PWRGD
5 V_OUT
DD PACKAGE
8-LEAD (3mm × 3mm) PLASTIC DFN
T_JMAX = 125°C, θ_JA = 43°C/W
EXPOSED PAD TO BE SOLDERED TO
ELECTRICALLY ISOLATED PCB HEATSINK
ORDER PART NUMBER
S8 PART MARKING ORDER PART NUMBER DD PART MARKING*
LTC4257CS8
LTC4257IS8
4257
4257I
LTC4257CDD
LTC4257IDD
LACT
Order Options Tape and Reel: Add #TR Lead Free: Add #PBF
Lead Free Tape and Reel: Add #TRPBF Lead Free Part Marking: http://www.linear.com/leadfree/
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grades are identified by a label on the shipping container.
ELECTRICAL CHARACTERISTICS _{The ● denotes the specifications which apply over the full operating}
temperature range, otherwise specifications are at T_A = 25°C. (Note 3)
SYMBOL
V_IN
I_{IN_ON}
I_{IN_CLASS}
∆I_CLASS
PARAMETER
CONDITIONS
Supply Voltage
Maximum Operating Voltage
Signature Range
Classification Range
UVLO Turn-On Voltage
UVLO Turn-Off Voltage
Voltage with Respect to GND Pin (Notes 4, 5, 6)
IC Supply Current when ON
V_IN = – 48V, Pins 5, 6 Floating
IC Supply Current During Classification V_IN = – 17.5V, Pin 2 Floating, V_OUT Tied to GND
(Note 7)
Current Accuracy During Classification 10mA < I_CLASS < 40mA, – 12.5V ≤ V_IN ≤ – 21V,
(Notes 8, 9)
MIN TYP MAX UNITS
●
– 57
V
● – 1.5
– 9.5
V
● – 12.5
– 21
V
● – 37.7 –39.2 – 40.2
V
● – 29.3 –30.5 – 31.5
V
●
3
mA
● 0.35 0.50 0.65
mA
●
±3.5
%
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