LTC3528/LTC3528B
3
3528fd
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 LTC3528/LTC3528B are tested under pulsed load conditions
such that T
J
≈ T
A
. The LTC3528E/LTC3528BE are guaranteed to meet
specifications from 0°C to 85°C junction temperature. Specifications
over –40°C to 125°C operating junction temperature range are assured
by design, characterization and correlation with statistical process
controls. Note that the maximum ambient temperature consistent with
these specifications is determined by specific operating conditions in
conjunction with board layout, the rated package thermal impedance
and other environmental factors. The junction temperature (T
J
, in °C) is
calculated from the ambient temperature (T
A
, in °C) and power dissipation
(P
D
, in Watts) according to the formula:
T
J
= T
A
+ (P
D
• θ
JA
)
where θ
JA
= 76°C/W is the package thermal impedance.
PARAMETER CONDITIONS MIN TYP MAX UNITS
SHDN Input High Voltage 0.88 V
SHDN Input Low Voltage 0.25 V
SHDN Input Current V
SHDN
= 1.2V 0.3 1 µA
PGOOD Threshold Percentage Referenced to Feedback Voltage Falling –7 –10 –13 %
PGOOD Low Voltage I
PGOOD
= 1mA
V
OUT
= 1.6V, I
PGOOD
= 1mA
0.05
0.05
0.1
0.2
V
V
PGOOD Leakage Current V
PGOOD
= 5.5V 0.01 1 µA
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the specified operating
temperature range, otherwise specifications are at T
A
= 25°C (Note 2). V
IN
= 1.2V, V
OUT
= 3.3V, unless otherwise noted.
Note 3: Specification is guaranteed by design and not 100% tested in
production.
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
76°C/W.
Note 7: The IC is tested in a feedback loop to make the measurement.
TYPICAL PERFORMANCE CHARACTERISTICS
Efficiency vs Load Current and V
IN
for V
OUT
= 1.8V (LTC3528)
Efficiency vs Load Current and V
IN
for V
OUT
= 3V (LTC3528)
(T
A
= 25°C unless otherwise noted)
LOAD CURRENT (mA)
0.01
EFFICIENCY (%)
POWER LOSS (mW)
60
80
100
100
3528 G01
40
20
50
70
90
30
10
0
10
100
1000
1
0.1
0.01
0.1
1
10
1000
V
IN
= 1V
V
IN
= 1.2V
V
IN
= 1.5V
EFFICIENCY
POWER
LOSS
LOAD CURRENT (mA)
0.01
EFFICIENCY (%)
POWER LOSS (mW)
60
80
100
100
3528 G26
40
20
50
70
90
30
10
0
10
100
1000
1
0.1
0.01
0.1
1
10
1000
V
IN
= 1V
V
IN
= 1.5V
V
IN
= 2.4V
EFFICIENCY
POWER
LOSS
