Datasheet
LT3959
2
3959fa
For more information www.linear.com/LT3959
pin conFiguraTion
absoluTe MaxiMuM raTings
V
IN
............................................................................40V
EN/UVLO (Note 2) .....................................................40V
DRIVE .......................................................................40V
PGOOD ...................................................................... 40V
SW ............................................................................40V
INTV
CC
........................................................................8V
SYNC ..........................................................................8V
(Note 1)
V
C
, SS .........................................................................3V
RT ............................................................................1.5V
GND, GNDK to SGND .............................................±0.3V
FBX ................................................................. –3V to 3V
Operating Junction Temperature Range (Note 3)
LT3959E/LT3959I .............................. –40°C to 125°C
Storage Temperature Range .................. –65°C to 125°C
12 13 14
TOP VIEW
UHEMA PACKAGE
36-LEAD (5mm × 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
NC
SGND
NC
SW
SW
NC
DRIVE
V
IN
EN/UVLO
SGND
NC
SW
SW
INTV
CC
PGOOD
SYNC
RT
SS
FBX
V
C
GNDK
GND
GND
GND
GND
GND
20
9
10
37
SGND
38
SW
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
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
TOP VIEW
FE PACKAGE
38-LEAD PLASTIC TSSOP
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
20
NC
NC
NC
V
C
FBX
SS
RT
SYNC
PGOOD
SGND
NC
SW
NC
NC
SW
NC
GNDK
GND
GND
NC
NC
NC
NC
EN/UVLO
V
IN
DRIVE
INTV
CC
NC
SGND
NC
SW
NC
NC
SW
NC
GND
GND
GND
39
SGND
40
SW
T
JMAX
=125°C, θ
JA
= 42°C/W, θ
JC
= 3°C/W
EXPOSED PAD (PIN 39) IS SGND, MUST BE SOLDERED TO SGND PLANE
EXPOSED PAD (PIN 40) IS SW, MUST BE SOLDERED TO SW PLANE