Datasheet
LT3477
2
3477fc
ABSOLUTE MAXIMUM RATINGS
SW Pin Voltage ........................................................ 42V
V
IN
, SHDN Pin Voltage ............................................. 25V
FBP, FBN Pin Voltage ................................................. 6V
V
REF
Pin Voltage......................................................... 6V
R
T
, V
C
, SS Pin Voltage ............................................... 6V
I
ADJ1
, I
ADJ2
Pin Voltage ............................................ 25V
I
SP1
, I
SP2
, I
SN1
, I
SN2
Pin Voltage ...............................42V
(Note 1)
Junction Temperature .......................................... 125°C
Operating Temperature Range (Note 2)
LT3477E ...............................................– 40°C to 85°C
LT3477I .............................................. –40°C to 125°C
Storage Temperature Range ...................– 65°C to 125°C
Lead Temperature (Soldering, 10 sec)
TSSOP .............................................................. 300°C
The ● indicates specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at T
A
= 25°C. V
IN
= 2.5V, V
SHDN
= 2.5V.
ELECTRICAL CHARACTERISTICS
PARAMETER CONDITIONS MIN TYP MAX UNITS
Minimum Input Voltage
l
2.3 2.5 V
Quiescent Current V
SHDN
= 0V
V
SHDN
= 2.5V, V
C
= 0.3V (Not Switching)
0.1
5.0
1.0
7.5
μA
mA
Reference Voltage E Grade
I Grade
l
l
1.216
1.210
1.235
1.235
1.250
1.260
V
V
Reference Voltage Line Regulation 2.5V < V
IN
< 25V, V
C
= 0.3V 0.01 0.03 %/V
FE PACKAGE
20-LEAD PLASTIC TSSOP
1
2
3
4
5
6
7
8
9
10
TOP VIEW
20
19
18
17
16
15
14
13
12
11
V
IN
R
T
SHDN
SS
V
C
FBN
FBP
V
REF
I
ADJ2
I
ADJ1
NC
NC
NC
SW
SW
GND
I
SN1
I
SP1
I
SN2
I
SP2
21
T
JMAX
= 125°C, θ
JA
= 40°C/W
EXPOSED PAD (PIN 21) IS PGND (MUST BE SOLDERED TO PCB)
20 19 18 17 16
6 7 8
TOP VIEW
21
UF PACKAGE
20-LEAD (4mm × 4mm) PLASTIC QFN
9 10
5
4
3
2
1
11
12
13
14
15
NC
NC
V
IN
R
T
SHDN
I
SP1
I
SN2
I
SP2
I
ADJ1
I
ADJ2
NC
SW
SW
GND
I
SN1
SS
V
C
FBN
FBP
V
REF
T
JMAX
= 125°C, θ
JA
= 37°C/W
EXPOSED PAD (PIN 21) IS PGND (MUST BE SOLDERED TO PCB)
LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE
LT3477EFE#PBF LT3477EFE#TRPBF 20-Lead Plastic TSSOP –40°C to 85°C
LT3477IFE#PBF LT3477IFE#TRPBF 20-Lead Plastic TSSOP –40°C to 125°C
LT3477EUF#PBF LT3477EUF#TRPBF 3477
20-Lead (4mm × 4mm) Plastic QFN
–40°C to 85°C
LT3477IUF#PBF LT3477IUF#TRPBF 3477
20-Lead (4mm × 4mm) Plastic QFN
–40°C to 125°C
Consult LTC Marketing for parts specifi ed with wider operating temperature ranges.
Consult LTC Marketing for information on non-standard lead based fi nish parts.
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/
PIN CONFIGURATION
ORDER INFORMATION