LTC3523-2_15 Datasheet, PDF (3/16 Pages) Linear Technology – Synchronous 600mA Step-Up and 400mA Step-Down DC/DC Converters

LTC3523/LTC3523-2
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T_A = 25°C. V_IN1 = V_IN2 = V_BAT = 2.4V, V_OUT = 3.3V, unless otherwise specified.
PARAMETER
CONDITIONS
MIN TYP MAX UNITS
MODE Leakage Current
Soft-Start Time
V_MODE = 5.5V
0.01
1
μA
500
μs
Step-Up Converter
Input Voltage Range
l 1.8
5.25
V
Output Voltage Adjust Range
(Note 6)
l 1.8
5.25
V
Feedback Voltage FB1
l 1.16 1.20 1.23
V
Feedback Input Current FB1
N-Channel Switch Leakage
P-Channel Switch Leakage
N-Channel Switch On Resistance
P-Channel Switch On Resistance
Peak Inductor Current
V_FB1 = 1.25V
V_SW = 5.5V
V_SW = 5.5V, V_OUT = 0V
V_OUT = 3.3V
V_OUT = 5V
V_OUT = 3.3V, I_SW = 100mA
V_OUT = 5V, I_SW = 100mA
(Note 7)
0
50
nA
0.20
2
μA
0.20
2
μA
0.36
Ω
0.22
Ω
0.33
Ω
0.31
Ω
l 600 1000
mA
Current Limit Delay to Output
(Note 6)
40
ns
Maximum Duty Cycle
Minimum Duty Cycle
Step-Down Converter
V_FB = 1V
V_FB = 1.5V
l 80
87
%
l
0
%
Input Voltage Range
l 1.8
5.5
V
Output Voltage Range
(Note 6)
l 0.615
5.5
V
Feedback Voltage FB2
l 585
600
615
mV
Feedback Input Current FB2
Reference Voltage Line Regulation
Output Voltage Line Regulation
Output Voltage Load Regulation
Maximum Duty Cycle
V_FB2 = 0.625V
I_OUT = 100mA (Notes 5, 6)
I_OUT = 100mA, 1.6V < V_IN < 5.5V (Note 6)
I_OUT = 0mA to 600mA (Note 6)
0
50
nA
0.04
%/V
0.04
%/V
1.0
%
100
%
Peak Inductor Current
(Note 7)
l 400
650
mA
N-Channel Switch On Resistance
P-Channel Switch On Resistance
SW Leakage
V_IN2 = 2.4V
V_IN2 = 2.4V
V_SHDN2 = 0V, V_SW2 = 0V or 5V, V_IN2 = 5.5V
0.33
Ω
0.58
Ω
0.20
2
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 LTC3523/LTC3523-2 are 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 control.
Note 3: The LTC3523/LTC3523-2 include an overtemperature
shutdown that is intended to protect the device during momentary
overload conditions. Junction temperature will exceed 125°C when the
overtemperature shutdown is active. Continuous operation above the
specified maximum operating junction temperature may impair device
reliability.
Note 4: Current is measured into the V_OUT pin since the supply is
bootstrapped to the output for the step-up. The current will reflect to the
input supply by: (V_OUT/V_IN) • Efficiency. The outputs are not switching in
sleep.
Note 5: The LTC3523/LTC3523-2 are tested in a propriety test mode that
connects FB2 to the output of the error amplifier.
Note 6: Specification is guaranteed by design and not 100% tested in
production.
Note 7: Current measurements are performed when the LTC3523/
LTC3523-2 are not switching. The current limit values in operation will be
somewhat higher due to the propagation delay of the comparator.
3523fb
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