Datasheet

LTC3539/LTC3539-2
3
35392fb
For more information www.linear.com/3539/3539-2
elecTrical characTerisTics
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 LTC3539E/LTC3539E-2 is guaranteed to meet performance
specifications from 0°C to 85°C. Specifications over –40°C to 85°C
operating temperature range are assured by design, characterization and
correlation with statistical process controls.
Note 3: Specification is guaranteed by design and not 100% tested in
production.
PARAMETER CONDITIONS MIN TYP MAX UNITS
Maximum Duty Cycle V
FB
= 1.15V
l
87 90 %
Minimum Duty Cycle V
FB
= 1.3V
l
0 %
Switching Frequency LTC3539
LTC3539-2
l
l
0.7
1.8
1
2
1.3
2.4
MHz
MHz
MODE Input High Voltage 0.88 V
MODE Input Low Voltage 0.3 V
MODE Input Current V
MODE
= 1.2V 0.3 1 µA
SHDN Input High Voltage 0.88 V
SHDN Input Low Voltage 0.3 V
SHDN Input Current V
SHDN
= 1.2V
V
SHDN
= 3.3V
0.3
1
1
2
µA
µA
The l denotes the specifications which apply over the specified
temperature range of –40°C to 85°C, otherwise specifications are at T
A
= 25°C. V
IN
= 1.2V, V
OUT
= 3.3V, unless otherwise noted.
Note 4: Current measurements are made when the output is not switching.
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 result in device degradation or failure.
Note 6: Failure to solder the exposed backside of the package to the PC
board ground plane will result in a thermal resistance much higher than
64°C/W.
Typical perForMance characTerisTics
Efficiency vs Load Current and
V
IN
, V
OUT
= 1.8V
Efficiency vs Load Current and
V
IN
, V
OUT
= 3.3V
LOAD CURRENT (mA)
EFFICIENCY (%)
100
10
90
70
50
30
80
60
40
20
0
POWER LOSS (mW)
1000
100
10
1
0.1
0.01
3539 G01
V
IN
= 1V
V
IN
= 1.2V
V
IN
= 1.5V
POWER LOSS
EFFICIENCY
0.1 100 1000101
LOAD CURRENT (mA)
EFFICIENCY (%)
100
10
90
70
50
30
80
60
40
20
0
3539 G02
V
IN
= 1.2V
V
IN
= 1.8V
V
IN
= 3V
POWER LOSS
EFFICIENCY
0.1 100 1000101
0.1
1
10
100
1000
POWER LOSS (mW)
(T
A
= 25°C unless otherwise noted)