Datasheet

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 ● 3mA
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 kΩ
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 kΩ
Tied to GND, IEEE 802.3af 2-Point Measurement
(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
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
WWWU
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
UU
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
1NC
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
LTC4257CS8-1
LTC4257IS8-1
ORDER PART NUMBER DD PART MARKING*
LBFZLTC4257CDD-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: http://www.linear.com/leadfree/