Datasheet

LTC3522
3
3522fa
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 LTC3522 is guaranteed to meet performance specifi cations
from 0°C to 85°C. Specifi cations 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 LTC3522 is not
switching. The current limit values in operation will be somewhat higher
due to the propagation delay of the comparators.
PARAMETER CONDITIONS MIN TYP MAX UNITS
Maximum Duty Cycle V
FB2
= 0.54V
●
100 %
Minimum Duty Cycle V
FB2
= 0.66V
●
0%
PGOOD Threshold V
FB2
Falling –11.3 –7.7 –4.1 %
Power Good Hysteresis 2.5 %
Buck-Boost Converter
Output Voltage
●
2.2 5.25 V
PMOS Switch Resistance 0.29
Ω
NMOS Switch Resistance 0.22
Ω
NMOS Switch Leakage V
SW1A
= V
SW1B
= 5V, PV
IN1
= PV
IN2
= 5V 0.1 5 µA
PMOS Switch Leakage V
SW1A
= V
SW1B
= 0V, PV
IN1
= PV
IN2
= 5V 0.1 10 µA
Feedback Voltage (Note 4)
●
0.97 1 1.03 V
Feedback Input Current 150 nA
Average Current Limit (Note 3) 0.65 0.85 A
Burst Mode Current Limit 230 340 mA
Reverse Current Limit (Note 3) 250 mA
Maximum Duty Cycle V
FB1
= 0.9V
●
70 80 %
Minimum Duty Cycle V
FB1
= 1.1V
●
0%
PGOOD Threshold V
FB1
Falling –12 –10 –8 %
Power Good Hysteresis 2.5 %
ELECTRICAL CHARACTERISTICS
The ● denotes the specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at T
A
= 25°C. PV
IN1
= PV
IN2
= 3.6V, V
OUT1
= 3.3V unless otherwise noted.
Note 4: The LTC3522 is tested in a proprietary non-switching test mode
that connects each FB pin to the output of the respective 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.