Datasheet

LTC3532
3
3532fc
The ● denotes the specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at T
A
= 25°C. V
IN
= V
OUT
= 3.6V, R
T
= 64.9k, unless otherwise specifi ed.
ELECTRICAL CHARACTERISTICS
PARAMETER CONDITIONS MIN TYP MAX UNITS
PMOS Switch Leakage Switches A and D 0.1 10 μA
NMOS Switch On Resistance Switches B and C 0.36 Ω
PMOS Switch On Resistance Switches A and D 0.42 Ω
Input Current Limit 0.8 1.1 1.45 A
Maximum Duty Cycle Boost (% Switch C On)
Buck (% Switch A On)
●
●
70
100
88 %
%
Minimum Duty Cycle
●
0%
Frequency Accuracy
●
575 740 885 kHz
Burst Threshold (Falling) 0.88 V
Burst Threshold (Rising) 1.12 V
Burst Current Ratio Ratio of I
OUT
to I
BURST
8000
Error Amp AVOL 90 dB
Error Amp Source Current V
C
= 1.4V 15 μA
Error Amp Sink Current V
C
= 2V 310 μA
SHDN/SS Threshold When IC is Enabled
When EA is at Maximum Boost Duty Cycle
●
0.4 1
2.2
1.5 V
V
SHDN/SS Input Current V
SHDN
= 5.5V 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 LTC3532E 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 correlations
with statistical process controls.
Note 3: Current measurements are performed when the outputs are not
switching.
Note 4: 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 result in device degradation or failure.
Effi ciency and Power Loss
vs Load Autoburst Mode
Effi ciency and Power Loss
vs Load
Fixed Frequency and Burst Mode
Quiescent Current vs V
IN
TYPICAL PERFOR A CE CHARACTERISTICS
UW
T
A
= 25°C, unless otherwise specifi ed.
LOAD CURRENT (mA)
60
EFFICIENCY (%)
POWER LOSS (mW)
80
100
50
70
90
0.1 10 100 1000
3532 G01
40
1
10
1000
0.1
100
0.01
1
POWER LOSS
V
OUT
= 3.3V
EFFICIENCY
3V
3.6V
4.2V
LOAD CURRENT (mA)
60
EFFICIENCY (%)
POWER LOSS (mW)
80
100
50
70
90
0.1 10 100 1000
3532 G02
40
1
1000
100
10
1
0.1
BURST EFFICIENCY
FIXED FREQUENCY
EFFICIENCY
FIXED FREQUENCY
POWER LOSS
BURST
POWER LOSS
V
IN
(V)
2.5
0
V
IN
QUIESCENT CURRENT (mA)
0.5
1.0
1.5
2.0
2.5
3.0
3.5 4.5 5.5
3532 G03
V
IN
QUIESCENT CURRENT BURST MODE (μA)
75
80
70
65
55
50
45
60
40
BURST MODE
2000kHz
1000kHz
500kHz
1500kHz
NOT SWITCHING