Datasheet
LTC3520
2
3520fa
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC3520EUF#PBF LTC3520EUF#TRPBF 3520
24-Lead (4mm × 4mm) Plastic QFN
–40°C to 85°C
LTC3520IUF#PBF LTC3520IUF#TRPBF 3520
24-Lead (4mm × 4mm) 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.
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
ELECTRICAL CHARACTERISTICS
ABSOLUTE MAXIMUM RATINGS
PV
IN1
, PV
IN2
, PV
IN3
, SV
IN
Voltage ................ –0.3V to 6V
SW1A, SW1B, SW2 Voltage
DC ............................................................ –0.3V to 6V
Pulsed <100ns ............................................ –1V to 7V
Voltage, All Other Pins ................................. –0.3V to 6V
Operating Junction Temperature Range
(Note 2) .................................................. –40°C to 125°C
Maximum Junction Temperature (Note 5) ............ 125°C
Storage Temperature Range ..................–65°C to 150°C
(Note 1)
PARAMETER CONDITIONS MIN TYP MAX UNITS
Input Voltage
l
2.2 5.5 V
Quiescent Current in Shutdown V
SD1
= V
SD2
= V
SD3
= 0V
LTC3520E
LTC3520I
l
l
0.01
0.5
1
4
μA
μA
Undervoltage Lockout SV
IN
Rising 2 2.2 V
Burst Mode Quiescent Current, Both Converters V
FB1
= V
FB2
= 0.88V, V
SD3
= 0V 55 μA
Oscillator Frequency R
T
= 54.9k
l
0.8 1 1.2 MHz
Buck Converter
PMOS Switch Resistance 0.32
Ω
NMOS Switch Resistance 0.18
Ω
NMOS Switch Leakage V
SW2
= 5V, S
VIN
= P
VIN1
= P
VIN2
= P
VIN3
= 5V 0.1 5 μA
PMOS Switch Leakage V
SW2
= 0V, S
VIN
= P
VIN1
= P
VIN2
= P
VIN3
= 5V 0.1 10 μA
24 23 22 21 20 19
7 8 9
TOP VIEW
UF PACKAGE
24-LEAD (4mm s 4mm) PLASTIC QFN
10
25
11 12
6
5
4
3
2
1
13
14
15
16
17
18
SV
IN
A
OUT
A
IN
R
T
PWM1
SD1
PV
IN3
PV
IN1
SW1A
PGND1
SW1B
V
OUT1
SD2
SD3
PV
IN2
SW2
PGND2
PWM2
FB1
SS1
SGND
V
C1
FB2
SS2
T
JMAX
= 125°C, θ
JA
= 37°C/W
EXPOSED PAD (PIN 25) IS GND, MUST BE SOLDERED TO PCB
The l denotes the specifi cations which apply over the full operating
junction temperature range, otherwise specifi cations are at T
A
= 25°C, S
VIN
= P
VIN1
= P
VIN2
= P
VIN3
= 3.6V, V
OUT1
= 3.3V, R
T
= 54.9k,
unless otherwise noted.
ORDER INFORMATION