Datasheet

LT3957
2
3957f
PIN CONFIGURATION
ABSOLUTE MAXIMUM RATINGS
V
IN
, EN/UVLO (Note 5), SW ......................................40V
INTV
CC
......................................................V
IN
+ 0.3V, 8V
SYNC ..........................................................................8V
VC, SS .........................................................................3V
RT
...............................................................................................
1.5V
SENSE1, SGND ..................Internally Connected to GND
SENSE2 ..................................................................±0.3V
FBX ................................................................. –6V to 6V
Operating Junction Temperature Range
(Note 2) .................................................. –40°C to 125°C
Maximum Junction Temperature .......................... 125°C
Storage Temperature Range .................. –65°C to 125°C
(Note 1)
12 13 14
TOP VIEW
SGND
37
SW
38
UHE PACKAGE
36-LEAD (5mm s 6mm) PLASTIC QFN
15 16 17
36 35 34 33 32 31 30
21
23
24
25
27
28
8
6
4
3
2
1NC
NC
SENSE2
SGND
SENSE1
SW
SW
NC
INTV
CC
V
IN
EN/UVLO
SGND
SGND
SW
SW
NC NC SYNC RT SS FBX VC
GND GND GND GND GND GND
20
9
10
T
JMAX
= 125°C, θ
JA
= 42°C/W, θ
JC
= 3°C/W
EXPOSED PAD (PIN 37) IS SGND, MUST BE SOLDERED TO SGND PLANE
EXPOSED PAD (PIN 38) IS SW, MUST BE SOLDERED TO SW PLANE
ORDER INFORMATION
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LT3957EUHE#PBF LT3957EUHE#TRPBF 3957
36-Lead (5mm × 6mm) Plastic QFN
–40°C to 125°C
LT3957IUHE#PBF LT3957IUHE#TRPBF 3957
36-Lead (5mm × 6mm) Plastic QFN
–40°C to 125°C
Consult LTC Marketing for parts specifi ed with wider operating temperature ranges. *The temperature grade is identifi ed by a label on the shipping container.
For more information on lead free part marking, go to:
http://www.linear.com/leadfree/
For more information on tape and reel specifi cations, go to:
http://www.linear.com/tapeandreel/