LTC3520
4
3520fa
LOAD CURRENT (mA)
1
0
EFFICIENCY (%)
POWER LOSS (mW)
10
30
40
50
100
70
10
100
20
80
90
60
0
50
150
200
250
300
100
1000
3520 G01
V
IN
= 4.2V
V
IN
= 2.7V
PWM MODE
Burst Mode
OPERATION
Burst Mode
OPERATION
POWER LOSS
L = COILCRAFT
MSS6132-4.7μH
Buck-Boost Effi ciency
Lithium-Ion to 3.3V
Buck Effi ciency
Lithium-Ion to 2.7V
PARAMETER CONDITIONS MIN TYP MAX UNITS
Propagation Delay A
OUT
Falling 11 μs
SD3 Input High Voltage 1.4 V
SD3 Input Low Voltage 0.4 V
SD3 Input Current 0.01 1 μA
ELECTRICAL CHARACTERISTICS
The l denotes the specifi cations which apply over the full operating
junction temperature range, otherwise specifi cations are at T
A
= 25°C, V
IN
= 3.6V, V
OUT1
= 3.3V, V
OUT2
= 1.8V, R
T
= 54.9k, unless
otherwise noted.
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: The LTC3520E is guaranteed to meet performance specifi cations
from 0°C to 85°C. Specifi cations over the –40°C to 85°C operating
junction temperature range are assured by design, characterization and
correlation with statistical process controls. The LTC3520I is guaranteed
to meet performance specifi cations over the full –40°C to 125°C operating
junction temperature range.
Note 3: Current measurements are performed when the LTC3520 is not
switching. The current limit values in operation will be somewhat higher
due to the propagation delay of the comparators.
Note 4: The LTC3520 is tested in a proprietary non-switching test mode
that internally connects the FB2 pin to the output of the buck converter
error amplifi er.
Note 5: This IC includes overtemperature protection that is intended
to protect the device during momentary overload conditions. Junction
temperature will exceed 125°C when overtemperature protection is active.
Continuous operation above the specifi ed maximum operating junction
temperature may impair device reliability.
LOAD CURRENT (mA)
1
0
EFFICIENCY (%)
POWER LOSS (mW)
10
30
40
50
100
70
10
100
20
80
90
60
0
100
300
400
500
700
200
800
600
1000
3520 G02
PWM MODE
Burst Mode OPERATION
Burst Mode
OPERATION
POWER LOSS
L = SUMIDA
CDRH3D16NP-4R7N
TYPICAL PERFORMANCE CHARACTERISTICS
(T
A
= 25°C, unless otherwise specifi ed)
