LTC3520 Datasheet, PDF (4/24 Pages) Linear Technology – Synchronous 1A Buck-Boost and 600mA Buck Converters

LTC3520
ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating temp-
erature range, otherwise specifications 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.
PARAMETER
Propagation Delay
⎯S⎯D⎯3 Input High Voltage
⎯S⎯D⎯3 Input Low Voltage
⎯S⎯D⎯3 Input Current
CONDITIONS
A_OUT Falling
MIN TYP MAX UNITS
11
µs
1.4
V
0.4
V
0.01
1
µA
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 LTC3520 is guaranteed to meet performance specifications
from 0°C to 85°C. Specifications over the –40°C to 85°C operating
temperature range are assured by design, characterization and correlation
with statistical process controls.
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 amplifier.
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 specified maximum operating junction
temperature may impair device reliability.
TYPICAL PERFORMANCE CHARACTERISTICS (T_A = 25°C, unless otherwise specified)
Buck-Boost Efficiency
Lithium-Ion to 3.3V
100
300
V_IN = 4.2V
90
80
V_IN = 2.7V
PWM MODE
250
70
Burst Mode
OPERATION
200
60
50
150
40
30
20
10
0
1
Burst Mode
OPERATION
100
POWER LOSS
50
L = COILCRAFT
MSS6132-4.7µH
0
10
100
1000
LOAD CURRENT (mA)
3520 G01
Buck Efficiency
Lithium-Ion to 2.7V
100
90 Burst Mode OPERATION
80
70
60
PWM MODE
50
40
30
Burst Mode
20
10 ^{L = SUMIDA}
CDRH3D16NP-4R7N
0
1
10
OPERATION
POWER LOSS
100
LOAD CURRENT (mA)
800
700
600
500
400
300
200
100
0
1000
3520 G02
3520f
4