Datasheet
LT3640
2
3640f
absoluTe MaxiMuM raTings
V
IN
, EN/UVLO Voltage (Note 7) .................................55V
WDE Voltage .............................................................30V
BST Above SW, SW1 Voltage ....................... –0.3V to 6V
SW1 Above SW Voltage ............................... –0.3V to 6V
V
IN2
, SYNC, EN2, PGOOD, WDI,
WDO, RST1, RST2, Voltages ....................... –0.3V to 6V
SS1, SS2, FB1, FB2, RT, CWDT,
CPOR Voltages………... ........................... –0.3V to 2.5V
(Note 1)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
TOP VIEW
FE PACKAGE
28-LEAD PLASTIC TSSOP
28
27
26
25
24
23
22
21
20
19
18
17
16
15
FB2
PGOOD
EN/UVLO
SYNC
SS1
FB1
RT
RST2
RST1
WDO
CWDT
CPOR
WDE
WDI
SS2
EN2
GND
SW2
V
IN2
GND
V
IN
BST
SW
SW1
DA
NC
GND
GND
29
GND
θ
JA
= 30°C/W, θ
JC
= 8°C/W
EXPOSED PAD (PIN 29) IS GND, MUST BE SOLDERED TO PCB
9 10
TOP VIEW
UFD PACKAGE
28-LEAD (4mm s 5mm) PLASTIC QFN
11 12 13
28 27 26 25 24
14
23
6
5
4
3
2
1
SYNC
SS1
FB1
RT
RST2
RST1
WDO
CWDT
SW2
V
IN2
GND
V
IN
BST
SW
SW1
DA
EN/UVLO
PGOOD
FB2
SS2
EN2
GND
CPOR
WDE
WDI
GND
GND
NC
7
17
18
19
20
21
22
16
8
15
29
GND
θ
JA
= 34°C/W, θ
JC
= 2.7°C/W
EXPOSED PAD (PIN 29) IS GND, MUST BE SOLDERED TO PCB
pin conFiguraTion
orDer inForMaTion
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LT3640EFE#PBF LT3640EFE#TRPBF LT3640FE 28-Lead Plastic TSSOP –40°C to 125°C
LT3640IFE#PBF LT3640IFE#TRPBF LT3640FE 28-Lead Plastic TSSOP –40°C to 125°C
LT3640EUFD#PBF LT3640EUFD#TRPBF 3640 28-Lead (4mm × 5mm) Plastic QFN –40°C to 125°C
LT3640IUFD#PBF LT3640IUFD#TRPBF 3640 28-Lead (4mm × 5mm) Plastic QFN –40°C to 125°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Consult LTC Marketing for information on non-standard lead based finish parts.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/
SW2 Voltage ................................ –0.3V to (V
IN2
+ 0.3V)
Operating Junction Temperature Range (Note 2)
LT3640E ................................................. –40°C to 125°C
LT3640I .................................................. –40°C to 125°C
Storage Temperature Range ................... –65°C to 150°C
Lead Temperature, FE Only (Soldering, 10 sec) .... 300°C