The LTC3118 is offered in thermally enhanced 24-lead
4mm × 5mm QFN and 28-lead TSSOP packages.
L,
LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks
and PowerPath and ThinSOT are trademarks of Linear Technology Corporation. All other trademarks
are the property of their respective owners. Protected by U.S. Patents, including 7709976.
Integrated High Efficiency Dual Input PowerPath™
Plus Buck-Boost DC/DC Converter
Ideal Diode or Priority V
IN
Select Modes
V
IN1
and V
IN2
Range: 2.2V to 18V
V
OUT
Range: 2V to 18V
Either V
IN
Can Be Above, Below or Equal to V
OUT
Generates 5V at 2A for V
IN
> 6V
1.2MHz Low Noise Fixed Frequency Operation
Current Mode Control
All Internal N-Channel MOSFETs
Pin-Selectable PWM or Burst Mode
®
Operation
Accurate, Independent RUN Pin Thresholds
Up to 94% Efficiency
V
IN
and V
OUT
Power Good Indicators
I
Q
of 50µA in Sleep, 2µA in Shutdown
4mm × 5mm 24-Lead QFN or 28-Lead TSSOP Packages
applicaTions
n
n
n
n
n
Systems with Multiple Input Sources
Back Up Power Systems
Wall Adapter or Li-Ion(s) Input to 5V
OUT
Battery or Super Capacitor Input for Reserve Power
Replace Diode-OR Designs with Higher Efficiency,
Flexibility and Performance
Typical applicaTion
3.3µH
0.1µF
V
IN1
22µF 47nF
V
IN1
BST1
CM1
10nF
10nF
V
IN2
22µF
47nF
CP1
CN1
CN2
CP2
V
IN2
CM2
PGND V
CC
GND
4.7µF
LTC3118
VC
V1GD
V2GD
PGD
MODE
SEL
RUN1
RUN2
3118 TA01a
0.1µF
SW1
SW2 BST2 V
OUT
400k
FB
22pF
100k
40.2k
1.8nF
SW1
10V/DIV
SEL
5V/DIV
V
OUT
5V
100µF
5V
OUT
AC-COUPLED
500mV/DIV
Input Switchover Response
V
IN1
= 5V, V
IN2
= 12V, V
OUT
= 5V AT 1A
INDICATORS
CONTROL
SIGNALS
SELECT V
IN2
SELECT V
IN1
3118 TA01b
100µs/DIV
3118fa
For more information
www.linear.com/LTC3118
1
LTC3118
absoluTe MaxiMuM raTings
(Note 1)
V
IN1
, V
IN2
Voltage....................................... –0.3V to 20V
V
OUT
Voltage .............................................. –0.3V to 20V
SW1 DC Voltage (Note 4)...............–0.3V to (V
IN1
+ 0.3V)
or (V
IN2
+ 0.3V)
SW2 DC Voltage (Note 4).............–0.3V to (V
OUT
+ 0.3V)
BST1 Voltage ..................... (SW1 – 0.3V) to (SW1 + 6V)
BST2 Voltage ....................(SW2 – 0.3V) to (SW2 + 6V)
RUN1, RUN2 Voltage.................................. –0.3V to 20V
PGD, V1GD, V2GD
Voltage ......................... –0.3V to 20V
CM1, CM2 Voltage ....................................... –0.3 to 20V
CP1 Voltage ........................ (V
IN1
– 0.3V) to (V
IN1
+ 6V)
CP2 Voltage ........................ (V
IN2
– 0.3V) to (V
IN2
+ 6V)
V
CC
, CN1, CN2 Voltage ................................... –0.3 to 6V
MODE, SEL, FB, VC Voltage ........................... –0.3 to 6V
Operating Junction Temperature Range (Notes 2, 3)
LTC3118E/LTC3118I ........................... –40°C to 125°C
LTC3118H .......................................... –40°C to 150°C
LTC3118MP........................................ –55°C to 150°C
Storage Temperature Range .................. –65°C to 150°C
Lead Temperature (Soldering, 10 sec) TSSOP ...... 300°C
pin conFiguraTion
TOP VIEW
TOP VIEW
CM1
CM2
CN1
CN2
CP1
24 23 22 21 20
SEL 1
V
IN1
2
RUN1 3
RUN2 4
V
CC
5
MODE 6
GND 7
8
VC
9 10 11 12
FB
V1GD
V2GD
PGD
25
PGND
19 CP2
18 V
IN2
17 SW1
16 BST1
15 BST2
14 SW2
13 V
OUT
CM1
CN1
CP1
SEL
V
IN1
RUN1
RUN2
V
CC
MODE
1
2
3
4
5
6
7
8
9
29
PGND
28 CM2
27 CN2
26 PGND
25 CP2
24 V
IN2
23 SW1
22 BST1
21 BST2
20 SW2
19 V
OUT
18 PGND
17 PGND
16
PGD
15
V2GD
GND 10
GND 11
VC 12
FB 13
V1GD
14
UFD PACKAGE
24-LEAD (4mm
×
5mm) PLASTIC QFN
T
JMAX
= 150°C,
θ
JC
= 3.4°C/W,
θ
JA
= 43°C/W
EXPOSED PAD (PIN 25) IS PGND, MUST BE SOLDERED TO PCB
FE PACKAGE
28-LEAD PLASTIC TSSOP
T
JMAX
= 150°C,
θ
JC
= 5°C/W,
θ
JA
= 30°C/W
EXPOSED PAD (PIN 29) IS PGND, MUST BE SOLDERED TO PCB
orDer inForMaTion
LEAD FREE FINISH
LTC3118EUFD#PBF
LTC3118IUFD#PBF
LTC3118HUFD#PBF
LTC3118MPUFD#PBF
LTC3118EFE#PBF
LTC3118IFE#PBF
LTC3118HFE#PBF
LTC3118MPFE#PBF
TAPE AND REEL
LTC3118EUFD#TRPBF
LTC3118IUFD#TRPBF
LTC3118HUFD#TRPBF
LTC3118MPUFD#TRPBF
LTC3118EFE#TRPBF
LTC3118IFE#TRPBF
LTC3118HFE#TRPBF
LTC3118MPFE#TRPBF
PART MARKING*
3118
3118
3118
3118
3118FE
3118FE
3118FE
3118FE
PACKAGE DESCRIPTION
24-Lead (4mm
×
5mm) Plastic QFN
24-Lead (4mm
×
5mm) Plastic QFN
24-Lead (4mm
×
5mm) Plastic QFN
24-Lead (4mm
×
5mm) Plastic QFN
28-Lead Plastic TSSOP
28-Lead Plastic TSSOP
28-Lead Plastic TSSOP
28-Lead Plastic TSSOP
TEMPERATURE RANGE
–40°C to 125°C
–40°C to 125°C
–40°C to 150°C
–55°C to 150°C
–40°C to 125°C
–40°C to 125°C
–40°C to 150°C
–55°C to 150°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
For more information on lead free part marking, go to:
http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to:
http://www.linear.com/tapeandreel/
3118fa
2
For more information
www.linear.com/LTC3118
LTC3118
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
Input Operating Voltage Range
Output Operating Voltage
Undervoltage Lockout Threshold on V
CC
Minimum V
IN
Start-Up Voltage
Input Quiescent Current in Shutdown
Input Quiescent Current in Burst Mode Operation
Input Quiescent Current in PWM Mode Operation
Output Quiescent Current in Burst Mode Operation
Oscillator Frequency
Oscillator Frequency Variation
Feedback Voltage
Feedback Voltage Line Regulation
Error Amplifier Transconductance
Feedback Pin Input Current
VC Source Current
VC Sink Current
RUN Pin Threshold: Accurate
RUN Pin Hysteresis: Accurate
RUN Pin Logic Threshold for V
CC
Enable/Shutdown
RUN Pin Leakage Current
V
CC
Output Voltage
V
CC
Load Regulation
V
CC
Line Regulation
V
CC
Current Limit
Average Inductor Current Limit (Note 5)
Overload Current Limit (Note 5)
Reverse Inductor Current Limit (Note 5)
Maximum Duty Cycle
Minimum Duty Cycle
SW1 and SW2 Forced Low Time
N-Channel Switch Resistance
Current from V
IN1
or V
IN2
PWM Mode
Percentage of Period SW2 Is Low in Boost Mode
Percentage of Period SW1 Is High in Boost Mode
Percentage of Period SW1 Is High in Buck Mode
BST1 or BST2 Capacitor Charge Time
Switch A1 (From V
IN1
to SW1)
Switch A2 (From V
IN2
to SW1)
Switch B (From SW1 to PGND)
Switch C (From SW2 to PGND)
Switch D (From PV
OUT
to SW2)
N-Channel Switch Leakage
Soft-Start Time
MODE and SEL Threshold Voltage
MODE and SEL Leakage
Pin = 5V
l
l
l
l
l
elecTrical characTerisTics
CONDITIONS
V
IN1
or V
IN2
, V
CC
≥ 2.5V
V
CC
Rising, V
IN
= 2.5V
V
CC
Powered from V
IN1
or V
IN2
(I
VCC
= 10mA)
RUN1 and RUN2 < 0.2V
Active V
IN1
or V
IN2
, FB = 1.2V
Inactive V
IN1
or V
IN2
, FB = 1.2V
Active V
IN1
or V
IN2
, FB = 0.8V
l
l
l
l
MIN
2.2
2
2.2
2.2
TYP
MAX
18
18
UNITS
V
V
V
V
µA
µA
µA
mA
µA
2.35
2.5
2
50
5
12
1
2.5
2.65
1000
0.98
1200
0.1
1.0
0.2
80
0
–14
14
1400
1.02
kHz
%/ V
V
%
µS
Active V
IN
= 3V to 18V
l
Active V
IN
= 3V to 18V
VC Current = ±4µA
FB = 1V
VC = 0.5V, FB = 0.8V
VC = 0.5V, FB = 1.2V
RUN1 or RUN2 Rising
Accurate RUN (Rising – Falling)
l
l
50
nA
µA
µA
1.17
0.2
3.5
1.22
170
0.65
3.8
–1
0.5
60
1.27
1.15
0.2
4.1
V
mV
V
µA
V
%
%
mA
RUN1 or RUN2 = 4V
I
VCC
= 1mA
I
VCC
= 1mA to 10mA
I
VCC
= 1mA, V
IN
= 5V to 18V
V
IN
> 6V
l
l
3.0
3.6
6
–200
5.2
A
A
mA
%
%
90
83
95
88
0
100
80
120
80
80
80
0.1
1
10
1.2
0.5
%
ns
mΩ
mΩ
mΩ
mΩ
mΩ
µA
ms
V
µA
3118fa
V
IN2
, V
IN2
or V
OUT
= 18V
0.3
0.75
0
For more information
www.linear.com/LTC3118
3
LTC3118
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
5
4.2
90
TYP
5.4
4.6
94
–2
300
1
MAX
5.8
5
98
UNITS
V
V
%
%
mV
µA
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 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.
