LTC3118_15 Datasheet, PDF (4/38 Pages) Linear Technology – 18V, 2A Buck-Boost DC/DC Converter with Low-Loss Dual Input PowerPath

LTC3118
Electrical Characteristics The l denotes the specifications which apply over the full operating junction
temperature range, otherwise specifications are at T_J ≈ T_A = 25°C (Note 2). Unless otherwise noted, V_IN1 or V_IN2 = 5V, V_OUT = 5V.
PARAMETER
V_IN1 Becomes Active Input in Ideal Diode Mode
PGD Threshold
PGD Hysteresis
V1GD, V2GD, PGD Low Voltage
V1GD, V2GD, PGD Leakage
CONDITIONS
V_IN2 = SEL = 5V
Rising
Falling
Percent of FB Voltage Rising
Percent of FB Voltage Falling
I_SINK = 5mA
Pin = 18V
MIN TYP MAX UNITS
5
5.4
5.8
V
4.2
4.6
5
V
90
94
98
%
–2
%
300
mV
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 LTC3118 is tested under pulsed load conditions such that T_J ≈
T_A. The LTC3112E is guaranteed to meet specifications from 0°C to 85°C
junction temperature. Specifications over the –40°C to 125°C operating
junction temperature range are assured by design, characterization and
correlation with statistical process controls. The LTC3118I is guaranteed
to meet specifications over the –40°C to 125°C operating junction
temperature, the LTC3118H is guaranteed to meet specifications over the
–40°C to 150°C operating junction temperature range and the LTC3118MP
is guaranteed and tested to meet specifications over the full –55°C to
150°C operating junction temperature range. High junction temperatures
degrade operating lifetimes; operating lifetime is derated for temperatures
greater than 125°C.
The maximum ambient temperature is determined by specific operating
conditions in conjunction with board layout, the rated package thermal
resistance and other environmental factors. The junction temperature
(T_J in °C) is calculated from the ambient temperature (T_A in °C) and power
dissipation (PD in Watts) according to the following formula:
T_J = T_A + (PD • θ_JA) where θ_JA is the thermal impedance of the package.
Note 3: This IC includes overtemperature protection that is intended
to protect the device during momentary overload conditions. Junction
temperature will exceed 150°C when overtemperature protection is active.
Continuous operation above the specified maximum operating junction
temperature may impair device reliability.
Note 4: Voltage transients on the switch pins beyond the DC limit specified
in the Absolute Maximum Ratings, are non disruptive to normal operation
when using good layout practices, as shown on the demo board or
described in the data sheet and application notes.
Note 5: Current measurements are performed when the LTC3118 is
not switching. The current limit values measured in operation will be
somewhat higher, while the reverse current thresholds may be lower due
to the propagation delay of the comparators and inductor value.
Typical Performance Characteristics T_A = 25°C, unless otherwise noted.
V_OUT = 12V, Efficiency and Power
Loss vs Load Current from V_IN1
100
5
90 ^BURST
80
4
70
PWM
60
5V_IN
3
50
12V_IN
18V_IN
40
2
30
20
1
10
LOSS
0
0
0.0001 0.001 0.01 0.1
1
10
LOAD CURRENT (A)
3118 G01
V_OUT = 12V, Efficiency and Power
Loss vs Load Current from V_IN2
100
5
90 ^BURST
80
4
70
60
3
50
40
5V_IN
30
12V_IN
18V_IN
20
10
PWM
2
1
LOSS
0
0
0.0001 0.001 0.01 0.1
1
10
LOAD CURRENT (A)
3118 G02
12V_OUT Efficiency vs V_IN1 or V_IN2
Voltage with 500mA and 1A Load
Current
100
95
90
85
80
V_IN1, LOAD = 500mA
75
V_IN2, LOAD = 500mA
V_IN1, LOAD = 1A
V_IN2, LOAD = 1A
70
2 4 6 8 10 12 14 16 18
INPUT VOLTAGE (V)
3118 G03
3118f
4
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