LTC3444_15 Datasheet, PDF (3/20 Pages) Linear Technology – Micropower Synchronous Buck-Boost DC/DC Converter for WCDMA Applications

LTC3444
ELECTRICAL CHARACTERISTICS
The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are T_A = 25°C.
V_IN = V_OUT = 3.6V unless otherwise noted.
PARAMETER
CONDITIONS
SHDN Threshold (On)
IC is Enabled
SHDN Threshold (Off)
IC is Disabled
SHDN Input Current
V_C Output Current
V_SHDN = 3.6V
V_C = GND
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 LTC3444E 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 correlation
with statistical process controls.
MIN TYP MAX
● 1.4
●
0.4
0.01 1
0.5 2
UNITS
V
V
μA
μA
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 is active.
Continuous operation above the specified maximum operating junction
temperature may result in device degradation or failure.
TYPICAL PERFOR A CE CHARACTERISTICS _{(TA = 25°C unless otherwise specified)}
Efficiency vs V_IN
Li-Ion to 1V Efficiency
Li-Ion to 3.3V Efficiency
85
90
0.18
V_OUT = 1.0V
80
0.16
80
I_OUT = 100mA
V_IN = 3.1V
70
0.14
75
70
I_OUT = 50mA
60
I_OUT = 65mA
50
0.12
V_IN = 4.4V
0.10
40
0.08
30
V_IN = 3.6V
0.06
65
20
10
60
0
3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5
1
V_IN (V)
3444 G03
Li-Ion to 4.2V Efficiency
V_IN = 4.4V
PLOSS
V_IN = 3.1V
10
100
OUTPUT CURRENT (mA)
0.04
0.02
0
1000
3444 G06
Error Amp Source Current
100
90
80
70
60
50
40
30
20
10
0
1
0.25
0.20
V_IN = 3.1V
V_IN = 3.6V
0.15
V_IN = 4.4V
0.10
V_IN = 3.6V
PLOSS
0.05
V_IN = 3.1V
10
100
OUTPUT CURRENT (mA)
Operating Frequency
0
1000
3444 G05
100
0.50
19
V_IN = 3.6V
1.8
90
0.45
80
V_IN = 3.1V
17
0.40
1.7
70
0.35
60
0.30
50
V_IN = 4.4V
0.25
40
0.20
30
0.15
20
V_IN = 4.4V PLOSS 0.10
10
V_IN = 3.1V
0
1
10
100
OUTPUT CURRENT (mA)
0.05
0
1000
3444 G04
15
13
11
9
7
V_C = 1V
FB = 0V
5
–55 –25
5 35 65
TEMPERATURE (°C)
95 125
3444 G07
1.6
1.5
1.4
1.3
1.2
–55 –25 0
35 65
TEMPERATURE (°C)
95 125
3444 G08
3444fb
3