LINER LTC3130 25v, 600ma buck-boost dc/dc converter with 1.6î¼a quiescent current Datasheet

LTC3130/LTC3130-1
25V, 600mA Buck-Boost
DC/DC Converter with
1.6µA Quiescent Current
DESCRIPTION
FEATURES
Regulates VOUT Above, Below or Equal to VIN
Wide VIN Range: 2.4V to 25V,
<1V to 25V (Using EXTVCC Input)
nn V
OUT Range: 1V to 25V
nn Adjustable Output Voltage (LTC®3130)
nn Four Selectable Fixed Output Voltages (LTC3130-1)
nn 1.2µA No-Load Input Current in Burst Mode®
Operation (VIN = 12V, VOUT = 5V)
nn 600mA Output Current in Buck Mode
nn Pin-Selectable 850mA/450mA Current Limit (LTC3130)
nn Up to 95% Efficiency
nn Pin-Selectable Burst Mode Operation
nn 1.2MHz Ultralow Noise PWM Frequency
nn Accurate RUN Pin Threshold
nn Power Good Indicator
nn Programmable Maximum Power Point Control
nn I = 500nA in Shutdown
Q
nn Thermally-Enhanced 20-Lead 3mm × 4mm QFN and
16-Lead MSOP Packages
nn
nn
APPLICATIONS
The LTC3130/LTC3130-1 are high efficiency, low noise,
600mA buck-boost converters with wide VIN and VOUT
ranges. For high efficiency operation at light loads,
Burst Mode operation can be selected, reducing the quiescent current to just 1.6µA. Converter start-up is achieved
from sources as low as 7.5µW.
The LTC3130/LTC3130-1 employ an ultralow noise, 1.2MHz
PWM architecture that minimizes solution footprint by
allowing the use of tiny, low profile inductors and ceramic
capacitors. Built-in loop compensation and soft-start
reduces external parts count and simplifies the design.
Features include an accurate RUN comparator threshold to
allow predictable regulator turn-on and a maximum power
point control (MPPC) capability that ensures maximum
power extraction from non-ideal sources such as photovoltaic panels. The LTC3130-1 includes an internal voltage
divider to provide four selectable fixed output voltages.
Additional features include a power good output, an external
VCC input and thermal shutdown.
The LTC3130 and LTC3130-1 are available in thermallyenhanced 20-lead 3mm × 4mm QFN and 16-lead MSOP
packages.
Long-Life, Battery-Operated Instruments
Portable Military Radios
nn Low Power Sensors
nn Solar Panel Post-Regulator/Charger
nn
nn
L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks
and PowerPath is a trademark of Linear Technology Corporation. All other trademarks are the
property of their respective owners.
TYPICAL APPLICATION
22nF
22nF
6.8µH
90
10µF
BST1
PVIN
VIN
RUN
VCC
SW1
SW2
LTC3130-1
BST2
VOUT
VOUT
12V
10µF 600mA
EXTVCC
MPPC
MODE
PGOOD
EFFICIENCY (%)
80
VIN
4 Li-Ion
+
Efficiency vs Load
100
70
60
50
40
30
20
VS1
VS2
10
VCC
GND
PGND
4.7µF
0
0.01
3130 TA01a
VIN = 14.4V, VOUT = 12V
0.1
1
10
LOAD (mA)
100
800
3130 TA01b
3130f
For more information www.linear.com/LTC3130
1
LTC3130/LTC3130-1
ABSOLUTE MAXIMUM RATINGS
(Notes 1, 8)
PVIN , VIN, VOUT Voltage..............................–0.3 to 27.5V
EXTVCC Voltage..........................................–0.3 to 27.5V
BST1, BST2 Voltage................ (SW – 0.3V) to (SW + 6V)
RUN, PGOOD Voltage..................................–0.3 to 27.5V
MODE, MPPC.................................................. –0.3 to 6V
VS1, VS2 Voltage (LTC3130-1)........................ –0.3 to 6V
ILIM, FB Voltage (LTC3130)............................ –0.3 to 6V
PGOOD Sink Current...............................................12mA
Operating Junction Temperature
Range (Notes 2, 5, 6).......................... –40°C to 125°C
Storage Temperature Range................... –65°C to 150°C
Lead Temperature (Soldering, 10sec)
MSE................................................................... 300°C
PIN CONFIGURATION
NC
PGND
PGND
SW1
TOP VIEW
20 19 18 17
BST1 1
16 BST2
PVIN 2
15 SW2
VIN 3
14 VOUT
21
GND
RUN 4
TOP VIEW
GND
BST1
SW1
PVIN
VIN
RUN
VCC
MPPC
13 PGOOD
12 EXTVCC
VCC 5
17
GND
16
15
14
13
12
11
10
9
SW2
BST2
VOUT
PGOOD
EXTVCC
MODE
VS1/ILIM
VS2/FB
MSE PACKAGE
16-LEAD PLASTIC MSOP
VS1/ILIM
9 10
VS2/FB
8
GND
11 MODE
7
GND
MPPC 6
1
2
3
4
5
6
7
8
TJMAX = 125°C, θJA = 40°C/W, θJC = 10°C/W (NOTE 6)
EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB
UDC PACKAGE
20-LEAD (3mm × 4mm) PLASTIC QFN
TJMAX = 125°C, θJA = 52°C/W, θJC = 6.8°C/W (NOTE 6)
EXPOSED PAD (PIN 21) IS GND, MUST BE SOLDERED TO PCB
ORDER INFORMATION
http://www.linear.com/product/LTC3130#orderinfo
LEAD FREE FINISH
TAPE AND REEL
PACKAGE DESCRIPTION
TEMPERATURE RANGE
LTC3130EUDC#PBF
LTC3130EUDC#TRPBF
PART MARKING*
LGTS
20-Lead (3mm × 4mm) Plastic QFN
–40°C to 125°C
LTC3130EUDC-1#PBF
LTC3130EUDC-1#TRPBF
LGTT
20-Lead (3mm × 4mm) Plastic QFN
–40°C to 125°C
LTC3130IUDC#PBF
LTC3130IUDC#TRPBF
LGTS
20-Lead (3mm × 4mm) Plastic QFN
–40°C to 125°C
LTC3130IUDC-1#PBF
LTC3130IUDC-1#TRPBF
LGTT
20-Lead (3mm × 4mm) Plastic QFN
–40°C to 125°C
LTC3130EMSE#PBF
LTC3130EMSE#TRPBF
3130
16-Lead Plastic MSOP
–40°C to 125°C
LTC3130EMSE-1#PBF
LTC3130EMSE-1#TRPBF
31301
16-Lead Plastic MSOP
–40°C to 125°C
LTC3130IMSE#PBF
LTC3130IMSE#TRPBF
3130
16-Lead Plastic MSOP
–40°C to 125°C
LTC3130IMSE-1#PBF
LTC3130IMSE-1#TRPBF
31301
16-Lead Plastic MSOP
–40°C to 125°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/. Some packages are available in 500 unit reels through
designated sales channels with #TRMPBF suffix.
2
3130f
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at TA = 25°C (Note 2). PVIN = VIN = 12V, VOUT = 5V unless otherwise noted.
PARAMETER
VIN Start-Up Voltage
Input Voltage Range
Output Voltage Adjust Range (LTC3130)
Feedback Voltage (LTC3130)
CONDITIONS
EXTVCC = 0V
EXTVCC > 3.15V, RUN > 1.1V
EXTVCC > 3.15V, RUN > 1.1V
MIN
l
l
l
l
For External FB Resistor Applications
From –40°C to +85°C (Note 3)
Feedback Input Current (LTC3130)
FB = 1.1V
VS1 = VS2 = 0V
Fixed VOUT Voltages (LTC3130-1)
VS1 = VCC, VS2 = 0V
VS1 = 0V, VS2 = VCC
VS1 = VS2 = VCC
VIN Quiescent Current – Shutdown
RUN < 0.2V
0.85V < RUN < 0.9V, EXTVCC = 0V
VIN Quiescent Current – UVLO
VIN Quiescent Current – Burst Mode Operation FB > 1.02V (LTC3130), VOUT > VREG (LTC3130-1),
(Sleeping)
MODE = 0V, RUN = VIN, MPPC > 1.05V
SW1 = SW2 = 0V, VIN = VOUT = 25V
NMOS Switch Leakage on VIN and VOUT
NMOS Switch On-Resistance
VCC = 4V
Inductor Average Current Limit
LTC3130-1 (Note 4), LTC3130: ILIM = VCC (Note 4)
LTC3130: ILIM = 0V (Note 4)
Inductor Peak Current Limit
LTC3130-1 (Note 4), LTC3130: ILIM = VCC (Note 4)
LTC3130: ILIM = 0V (Note 4)
Maximum Boost Duty Cycle
LTC3130-1: VOUT < VREG (Note 7),
LTC3130: FB < 0.975V (Note 7)
(Percentage of Period SW2 is Low)
Minimum Duty Cycle
LTC3130-1: VOUT > VREG (Note 7),
LTC3130: FB > 1.02V (Note 7)
Switching Frequency
SW1 and SW2 Minimum Low Time
(Note 3)
MPPC Reference Voltage
MPPC Input Current
MPPC = 5V
RUN Logic Threshold to Enable Reference
RUN Threshold to Enable Switching (Rising)
VIN > 2.4V or EXTVCC > 3.15V
RUN Threshold Hysteresis
RUN Input Current
RUN = 25V
RUN = 1V
ILIM Input Logic High
(LTC3130)
ILIM Input Logic Low
(LTC3130)
ILIM Input Current
(LTC3130) ILIM = 5V
VS1, VS2 Input Logic High
(LTC3130-1)
VS1, VS2 Input Logic Low
(LTC3130-1)
VS1, VS2 Input Current
(LTC3130-1) VS1, VS2 = 5V
MODE Input Logic High
MODE Input Logic Low
MODE Input Current
MODE = 5V (If RUN is Low or VCC is in UVLO)
MODE = 5V (If Switching is Enabled)
l
l
l
l
l
l
l
l
l
l
0.6
1.0
0.975
0.980
1.75
3.20
4.85
11.64
660
250
0.9
0.6
91
TYP
2.30
0.6
1.000
1.000
0.1
1.80
3.3
5.0
12.0
500
1.4
1.6
5
0.35
850
450
1.3
0.85
94
l
l
1.00
l
0.95
l
l
0.2
1.01
90
l
1.1
l
1.20
70
1.00
1
0.6
1.05
100
1
0.1
1200
650
1.7
1.15
97
0
%
1.40
1.05
20
0.85
1.09
110
30
5
1
0.35
20
1
1.7
0.35
20
4
1.1
1.1
l
UNITS
V
V
V
V
V
V
nA
V
V
V
V
nA
µA
µA
nA
Ω
mA
mA
A
A
%
0.35
20
l
l
100
1
l
l
MAX
2.40
1.0
25
25
1.020
1.020
10
1.85
3.39
5.125
12.30
850
2.4
2.7
MHz
ns
V
nA
V
V
mV
nA
nA
V
V
nA
V
V
nA
V
V
nA
µA
3130f
For more information www.linear.com/LTC3130
3
LTC3130/LTC3130-1
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at TA = 25°C (Note 2). PVIN = VIN = 12V, VOUT = 5V unless otherwise noted.
PARAMETER
Soft-Start Time
VCC Voltage
VCC Voltage -– Shutdown
VCC Dropout Voltage (VIN – VCC)
VCC Current Limit
VCC UVLO Threshold (Rising)
VCC UVLO Hysteresis
EXTVCC Enable Threshold
EXTVCC Enable Hysteresis
EXTVCC Input Operating Range
EXTVCC Quiescent Current – Burst Mode
Operation (Sleeping)
EXTVCC Quiescent Current – Shutdown
EXTVCC Current Limit
VIN Sleep Current When Powered by EXTVCC
VOUT UV Threshold
VOUT UV Hysteresis
VOUT Quiescent Current – Shutdown
CONDITIONS
For Average Inductor Current to Reach Limit
(EXTVCC or VIN) > 4.7V, RUN > 0.85V
RUN ≤ 0.2V
VIN = 3.0V, Switching
VCC = 0V
l
2.20
100
2.85
l
3.15
l
EXTVCC > 3.15V, FB >1.02V (LTC3130), MPPC > 1.05V
VOUT > VREG (LTC3130-1), MODE = 0V, RUN > 1.10V
EXTVCC = 5V, RUN < 0.2V
VCC = 0V, EXTVCC = 15V
FB > 1.02V (LTC3130), VOUT > VREG (LTC3130-1),
EXTVCC > 3.15V, MODE = 0V,
RUN >1.10V, VIN = 12V, MPPC > 1.05V
Rising
VOUT Quiescent Current – Burst Mode
Operation (Sleeping)
MODE = 0V, FB > 1.02V, MPPC > 1.05V
PGOOD Threshold, Rising
PGOOD Hysteresis
PGOOD Voltage Low
PGOOD Leakage
Referenced to Programmed VOUT Voltage
Referenced to Programmed VOUT Voltage
ISINK = 1mA
PGOOD = 25V
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 LTC3130/LTC3130-1 is tested under pulsed load conditions
such that TJ ≈ TA. The LTC3130E/LTC3130E-1 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 LTC3130I/LTC3130I-1 is guaranteed over the –40°C to 125°C
operating junction temperature range. The junction temperature (TJ) is
calculated from the ambient temperature (TA) and power dissipation (PD)
according to the formula:
TJ = TA + (PD • θJA°C/W),
where θJA is the package thermal impedance. Note that the maximum
ambient temperature consistent with these specifications is determined by
specific operating conditions in conjunction with board layout, the rated
thermal package thermal resistance and other environmental factors.
4
MIN
TYP
12
4
3.25
50
17
2.3
120
3.0
260
1.6
l
0.35
100
34
2.40
135
3.15
25
2.5
UNITS
ms
V
V
mV
mA
V
mV
V
mV
V
µA
400
32
600
750
68
nA
mA
nA
0.7
55
(VOUT–1)
0.95
V
mV
µA
27
(VOUT–1)
–7.0
MAX
27
–5.0
2.5
165
1
(VOUT)
17
(VOUT)
17
–3.0
250
50
µA
%
%
mV
nA
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 165°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 much higher thermal resistance.
Note 7: Switching time measurements are made in an open-loop test
configuration. Timing in the application may vary somewhat from these values due
to differences in the switch pin voltage during non-overlap durations when switch
pin voltage is influenced by the magnitude and duration of the inductor current.
Note 8: Voltage transients on the switch pin(s) beyond the DC limits
specified in the Absolute Maximum Ratings are non-disruptive to normal
operation when using good layout practices as described elsewhere in the
data sheet and application notes and as seen on the product demo board.
3130f
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
TYPICAL PERFORMANCE CHARACTERISTICS
70
Efficiency, VOUT = 3.3V,
PWM ModeOUT
80
60
50
40
30
70
50
40
30
60
50
40
30
20
10
10
10
1
10
100
LOAD CURRENT (mA)
1k
0.1
3130 G01
Efficiency, VOUT = 12V,
PWM ModeOUT
100
VIN = 2.5V
VIN = 3.6V
VIN = 5V
VIN = 12V
VIN = 24V
80
70
40
30
50
40
10
0
0.01
1k
VIN = 2.5V
VIN = 3.6V
VIN = 5V
VIN = 12V
VIN = 24V
30
20
1
10
100
LOAD CURRENT (mA)
0.1
3130 G04
1k
1
10
100
LOAD CURRENT (mA)
10
1
0.1
1k
0.001
0.01
Power Loss, VOUT = 3.3V, Burst
Mode
OUT Operation (LTC3130-1)
100
40
VIN = 2.5V
VIN = 3.6V
VIN = 5V
VIN = 12V
VIN = 24V
30
20
10
0
0.01
0.1
1
10
100
LOAD CURRENT (mA)
10
1
0.1
3130 G07
0.001
0.01
1k
Efficiency, VOUT = 5V, Burst Mode
Operation
(LTC3130-1)
OUT
80
VIN = 2.5V
VIN = 3.6V
VIN = 5V
VIN = 12V
VIN = 24V
0.01
1k
1
10
100
LOAD CURRENT (mA)
90
EFFICIENCY (%)
POWER LOSS (mW)
50
0.1
3130 G06
100
60
VIN = 2.5V
VIN = 3.6V
VIN = 5V
VIN = 12V
VIN = 24V
0.01
90
80
1k
Power Loss, VOUT = 1.8V, Burst
Mode
OUT Operation (LTC3130-1)
3130 G05
Efficiency, VOUT = 3.3V, Burst
Mode
OUT Operation (LTC3130-1)
70
1
10
100
LOAD CURRENT (mA)
100
60
10
100
1k
70
20
0.1
Efficiency, VOUT = 1.8V, Burst
Mode
OUT Operation (LTC3130-1)
80
50
0.1
3130 G03
90
60
0
0.01
0
0.01
1k
POWER LOSS (mW)
90
1
10
100
LOAD CURRENT (mA)
3130 G02
EFFICIENCY (%)
100
EFFICIENCY (%)
70
20
0.1
VIN = 2.5V
VIN = 3.6V
VIN = 5V
VIN = 12V
VIN = 24V
80
60
0
0.01
Efficiency, VOUT = 5V,
vs Load,
VOUT = 5V, PWM Mode
PWM
Mode
90
20
0
0.01
EFFICIENCY (%)
100
VIN = 2.5V
VIN = 3.6V
VIN = 5V
VIN = 12V
VIN = 24V
90
EFFICIENCY (%)
80
EFFICIENCY (%)
100
VIN = 2.5V
VIN = 3.6V
VIN = 5V
VIN = 12V
VIN = 24V
90
EFFICIENCY (%)
100
Efficiency, VOUT = 1.8V,
vs Load,
VOUT = 1.8V, PWM Mode
PWM
Mode
TA = 25°C, unless otherwise noted.
0.1
1
10
100
LOAD CURRENT (mA)
70
60
50
40
VIN = 2.5V
VIN = 3.6V
VIN = 5V
VIN = 12V
VIN = 24V
30
20
10
1k
3130 G08
0
0.01
0.1
1
10
100
LOAD CURRENT (mA)
1k
3130 G09
3130f
For more information www.linear.com/LTC3130
5
LTC3130/LTC3130-1
TYPICAL PERFORMANCE CHARACTERISTICS
1k
Power Loss, VOUT = 5V, Burst
Mode
(LTC3130-1)
VOUT =Operation
5V, Burst Mode
100
TA = 25°C, unless otherwise noted.
Efficiency, VOUT = 12V, Burst
Mode
OUT Operation (LTC3130-1)
1k
Power Loss, VOUT = 12V, Burst
Mode
OUT Operation (LTC3130-1)
90
80
1
0.1
VIN = 2.5V
VIN = 3.6V
VIN = 5V
VIN = 12V
VIN = 24V
0.01
0.001
0.01
0.1
1
10
100
LOAD CURRENT (mA)
70
60
50
40
VIN = 2.5V
VIN = 3.6V
VIN = 5V
VIN = 12V
VIN = 24V
30
20
10
0
0.01
1k
0.1
1
10
100
LOAD CURRENT (mA)
Efficiency, VOUT = 8V,
PWM
OUT Mode (LTC3130)
80
70
50
40
30
1k
50
40
20
10
1
10
100
LOAD CURRENT (mA)
0
0.01
1k
VIN = 2.5V
VIN = 3.6V
VIN = 5V
VIN = 12V
VIN = 24V
30
1k
Power Loss , VOUT = 8V, Burst
Mode
(LTC3130)
VOUT =Operation
8V, Burst Mode
0.1
1
10
100
LOAD CURRENT (mA)
10
1
VIN = 2.5V
VIN = 3.6V
VIN = 5V
VIN = 12V
VIN = 24V
0.1
0.01
0.01
1k
0.1
1
10
100
LOAD CURRENT (mA)
Efficiency, VOUT = 15V
V(LTC3130)
OUT = 15V
1k
1k
3130 G15
3130 G14
Power Loss, VOUT = 15V, Burst
Mode
OUT Operation (LTC3130)
100
90
Efficiency, VOUT = 24V
(LTC3130)
OUT
90
80
80
60
50
40
30
EFFICIENCY (%)
100
70
POWER LOSS (mW)
EFFICIENCY (%)
1
10
100
LOAD CURRENT (mA)
100
3130 G13
10
1
20
VIN = 3.6V
VIN = 5V
VIN = 12V
VIN = 24V
10
0
0.01
6
0.1
3130 G12
Efficiency, VOUT = 8V, Burst Mode
Operation
VOUT = 8V, (LTC3130)
Burst Mode
60
10
100
0.01
0.01
1k
70
20
0.1
VIN = 2.5V
VIN = 3.6V
VIN = 5V
VIN = 12V
VIN = 24V
0.1
80
60
0
0.01
1
90
EFFICIENCY (%)
EFFICIENCY (%)
100
VIN = 2.5V
VIN = 3.6V
VIN = 5V
VIN = 12V
VIN = 24V
90
10
3130 G11
3130 G10
100
POWER LOSS (mW)
EFFICIENCY (%)
10
100
POWER LOSS (mW)
POWER LOSS (mW)
100
0.1
1
10
100
LOAD CURRENT (mA)
Burst Mode OPERATION:
VIN = 3.6V
VIN = 5V
VIN = 12V
VIN = 24V
PWM:
1k
3130 G16
0.1
0.01
0.1
1
10
100
LOAD CURRENT (mA)
60
50
40
30
20
10
1k
3130 G17
VIN = 3.6V
VIN = 5V
VIN = 12V
VIN = 24V
70
0
0.01
0.1
1
10
100
LOAD CURRENT (mA)
Burst Mode OPERATION:
VIN = 5V
VIN = 12V
VIN = 24V
PWM:
1k
3130 G18
VIN = 5V
VIN = 12V
VIN = 24V
3130f
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
TYPICAL PERFORMANCE CHARACTERISTICS
Power Loss, VOUT = 24V, Burst Mode
Operation (LTC3130)
1k
TA = 25°C, unless otherwise noted.
VIN Shutdown Current vs
VIN (RUN = 0V, EXTVCC = 0V)
Maximum Output Current
vs VIN and VOUT
VOUT = 24V, Burst Mode
IN
700
OUT
0.90
600
0.80
10
400
300
VOUT = 1.8V
VOUT = 3.3V
VOUT = 5V
VOUT = 12V
VOUT = 25V
200
1
0.1
0.01
VIN = 5V
VIN = 12V
VIN = 24V
0.1
100
1
10
100
LOAD CURRENT (mA)
0
1k
0
5
10
15
VIN (V)
VIN UVLO Current
vs VIN (0.85V ≤ RUN ≤ 1.01V,
EXTVCC = 0V)
CC
0.30
0.10
0
25
1.00
0.80
0.40
10
15
20
25
3130 G21
No-Load Input Current in Burst
Mode Operation vs VIN and VOUT
(LTC3130-1,
MODE = 0V)
and V
(LTC3130-1, MODE = 0V)
15
OUT
5.0
VOUT = 1.8V
VOUT = 3.3V
VOUT = 5V
VOUT =1 2V
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
5
0.20
5
3130 G20
10
0.60
0
VIN (V)
IIN (μA)
20
IIN (μA)
0.5
0
5
10
15
VIN (V)
20
0
25
IN
10
15
VIN (V)
20
25
3130 G25
0
5
3130 G23
10
15
VIN (V)
20
25
3130 G24
Average Inductor Current Limit
vs
MPPC Voltage
vs MPPC Voltage
0.80
0.70
0.09
0.06
VOUT = 1.8V
VOUT = 3.3V
VOUT = 5V
VOUT = 12V
VOUT = 25V
0.03
5
5
0
25
OUT
10
0
20
0.12
IOUT (A)
15
IN
0.15
VOUT = 1.8V
VOUT = 3.3V
VOUT = 5V
VOUT = 12V
VOUT = 25V
20
10
15
VIN (V)
Burst Mode Operation, Load
Current Threshold vs VIN and
VOUT (MODE = 0V)
OUT
25
5
3130 G22
No-Load Input Current in Fixed
Frequency vs VIN and VOUT
(MODE = VCC)
30
0
INDUCTOR CURRENT LIMIT (A)
VIN CURRENT (μA)
0.40
IOUT = 2μA (FB DIVIDER)
VOUT = 1.8V
VOUT = 3.3V
VOUT = 5V
VOUT = 12V
VOUT = 25V
25
1.20
IIN (mA)
0.50
OUT
30
1.40
0
0.60
No-Load Input Current in Burst
Mode Operation vs VIN and VOUT
(LTC3130, MODE = 0V)
1.60
0
0.70
0.20
20
3130 G19
1.80
VIN CURRENT (μA)
500
IOUT (mA)
POWER LOSS (mW)
100
CC
1.00
0
0
5
10
15
VIN (V)
20
0.60
0.50
0.40
0.30
0.20
0.10
25
3130 G26
0
0.95
0.98
1.01
1.04
MPPC (V)
1.07
1.10
3130 G27
3130f
For more information www.linear.com/LTC3130
7
LTC3130/LTC3130-1
TYPICAL PERFORMANCE CHARACTERISTICS
Average Current Limit vs
Temperature (Normalized to 25°C)
FB Voltage vs Temperature
LTC3130 (Normalized to 25°C)
LTC3130–1 (Normalized to 25 C)
0.00
0.00
–1.00
–0.10
–0.10
–2.00
–0.20
–3.00
–4.00
–5.00
–6.00
–7.00
–8.00
CHANGE IN OUTPUT VOLTAGE (%)
0
CHANGE IN FB VOLTAGE (%)
CHANGE IN AVERAGE CURRENT LIMIT (%)
Output Voltage vs Temperature
LTC3130–1 (Normalized to 25°C)
LTC3130 (Normalized to 25 C)
(Normalized to 25 C)
–0.30
–0.40
–0.50
–0.60
–0.70
–0.80
–0.90
–9.00
–10.00
–50 –25
0
–1.00
–50 –25
25 50 75 100 125 150
TEMPERATURE (° C)
0
–4.00
–5.00
–6.00
–7.00
–8.00
–9.00
–10.00
–50 –25
0
–0.90
–1.00
–50 –25
0
25 50 75 100 125 150
TEMPERATURE (° C)
3130 G30
Accurate RUN Threshold vs
Temperature (Normalized to 25°C)
99
98
97
2.4
Switch
Temperature
DS(ON)vsvsTemperature
Switch R
Rdson
2.8
3.2
VCC (V)
3.6
4.0
–0.20
–0.30
–0.40
–0.50
–0.60
–0.70
–0.80
–0.90
–1.00
–50 –25
3130 G32
0.50
SW2
(5V/DIV)
0.42
0.45
RDSON (Ω)
25 50 75 100 125 150
TEMPERATURE (° C)
Fixed Frequency PWM
Waveforms (Buck Region)
CC
0.45
0
3130 G33
Switch
vsVVCC
DS(ON)vs
Switch R
Rdson
0.55
RDSON (Ω)
–0.80
0.00
3130 G31
0.35
–0.70
–0.10
25 50 75 100 125 150
TEMPERATURE (° C)
0.40
–0.60
CHANGE IN RUN THRESHOLD (%)
–3.00
–0.50
CC
100
NORMALIZED OSCILLATOR FREQUENCY (%)
–2.00
–0.40
Oscillator Frequency vs VCC
(Normalized
to VCC = 4V)
Oscillator Frequency
vs V
(Normalized to 25 C)
–1.00
–0.30
3130 G29
Oscillator Frequency vs
Temperature (Normalized to 25°C)
0
–0.20
25 50 75 100 125 150
TEMPERATURE (° C)
3130 G28
CHANGE IN OSCILLATOR FREQUENCY (%)
TA = 25°C, unless otherwise noted.
SW1
(10V/DIV)
0.39
INDUCTOR
CURRENT
(0.5A/DIV)
0.36
0.30
0.20
–50 –25
0
25 50 75 100 125 150
TEMPERATURE (° C)
3131 G34
8
200nsec/DIV
0.33
0.25
0.30
2.5
3
3.5
VCC (V)
3130 G36
4
3134 G35
3130f
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
TYPICAL PERFORMANCE CHARACTERISTICS
Fixed Frequency PWM
Waveforms (Buck-Boost Region)
Fixed Frequency PWM
Waveforms (Boost Region)
SW2
(5V/DIV)
SW2
(10V/DIV)
SW1
(5V/DIV)
SW1
(5V/DIV)
INDUCTOR
CURRENT
(0.5A/DIV)
INDUCTOR
CURRENT
(0.5A/DIV)
200nsec/DIV
TA = 25°C, unless otherwise noted.
Fixed Frequency Output
Voltage Ripple
VOUT
(50mV/DIV)
INDUCTOR
CURRENT
(0.2A/DIV)
0
3130 G37
3130 G38
200nsec/DIV
PWM to Burst Mode Operation
Transition
Burst Mode Operation Waveforms
VIN
(10V/DIV)
VCC
(2V/DIV)
MODE PIN
(2V/DIV)
VOUT
(2V/DIV)
INDUCTOR
CURRENT
(0.2A/DIV)
INDUCTOR
CURRENT
(0.2A/DIV)
INDUCTOR
CURRENT
(0.2A/DIV)
20μsec/DIV
3130 G40
1msec/DIV
3130 G41
2msec/DIV
Start-Up Sequence When Raising
RUN Pin (VIN = 12V)
RUN
(5V/DIV)
VCC Response to a Step on
EXTVCC (VIN = 3V)
VCC Response to a Step on
EXTVCC (VIN > 4V)
VCC
(2V/DIV)
VCC
(2V/DIV)
VCC
(2V/DIV)
VOUT
(2V/DIV)
0
0
INDUCTOR
CURRENT
(0.2A/DIV)
EXTVCC
(5V/DIV)
0
EXTVCC
2msec/DIV
3138 G43
3130 G42
COUT = 22µF
12VIN, 5VOUT,
ILOAD = 20mA, COUT = 22µF
5VOUT
ILOAD =10mA
COUT = 22µF
3130 G39
Start-Up Sequence When
Applying VIN (RUN Tied to VIN)
VOUT
(100mV/
DIV)
VOUT
(50mV/DIV)
500nsec/DIV
12VIN, 5VOUT,
ILOAD = 0.5A, COUT = 22µF
(5V/DIV)
0
1msec/DIV
3130 G44
1msec/DIV
3130 G45
3130f
For more information www.linear.com/LTC3130
9
LTC3130/LTC3130-1
TYPICAL PERFORMANCE CHARACTERISTICS
Step Load Transient Response in
Fixed Frequency
TA = 25°C, unless otherwise noted.
VOUT
(2V/DIV)
PGOOD
(2V/DIV)
VOUT
(100mV/DIV)
VOUT
(100mV/DIV)
INDUCTOR
CURRENT
(0.2A/DIV)
INDUCTOR
CURRENT
(0.5A/DIV)
3130 G46
500μsec/DIV
12VIN, 5VOUT,
50mA to 500mA LOAD STEP
COUT = 22µF, L = 10μH
PGOOD Response to a Drop in
VOUT Due to a Step Overload
Step Load Transient Response in
Burst Mode Operation
INDUCTOR
CURRENT
(0.5A/DIV)
500μsec/DIV
3130 G47
1msec/DIV
12VIN, 5VOUT,
10mA to 250mA LOAD STEP
COUT = 22µF, L = 10μH
MPPC Response to an Overload
(VMPPC Set to 5V at VIN)
3130 G48
VIN Line Step Response in
Fixed Frequency
VOUT
(5V/DIV)
VIN
(5V/DIV)
VOUT
(1V/DIV)
VIN
(10V/DIV)
INDUCTOR
CURRENT
(0.2A/DIV)
INDUCTOR
CURRENT
(0.2A/DIV)
3130 G49
2msec/DIV
VOC = 9V
VOUT = 12V
RIN = 20Ω
CIN = 33μF
VOUT
(2V/DIV)
VOUT
(1V/DIV)
VIN
(10V/DIV)
INDUCTOR
CURRENT
(0.2A/DIV)
50μsec/DIV
3130 G51
5VOUT,
5V TO 25V VIN STEP,
COUT = 22µF, L = 10μH,
LIGHT LOAD
10
3130 G50
Output Voltage Short-Circuit
Waveforms
VIN Line Step Response in
Burst Mode Operation
INDUCTOR
CURRENT
(0.2A/DIV)
50μsec/DIV
5VOUT,
5V TO 25V VIN STEP,
COUT = 22µF, L = 10μH,
LIGHT LOAD
10μsec/DIV
3130 G52
3130f
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
PIN FUNCTIONS
(QFN/MSOP)
BST1 (Pin 1/Pin 2): Boot-Strapped Floating Supply for
High Side NMOS Gate Drive. Connect to SW1 through a
22nF capacitor, as close to the part as possible.
PVIN (Pin 2/Pin 4): Power Input for the Buck-Boost
Converter. A 4.7μF or larger bypass capacitor should be
connected between this pin and the ground plane. The
capacitor should be located as close to the IC as possible.
When powered through long leads or from a high ESR
source, a larger bulk input capacitor (typically 47μF or
larger) may be required.
VIN (Pin 3/Pin 5): Input Voltage for the VCC Regulator.
Connect a minimum of 1µF ceramic decoupling capacitor
from this pin to the ground plane.
RUN (Pin 4/Pin 6): Input to the Run Comparator. Raising this pin above 1.05V enables the converter. Pull this
pin above 0.6V (typical) to put the converter in “standby
mode”, where the internal reference will be enabled, but
the part will not be switching. Connecting this pin to a
resistor divider from VIN to ground allows programming
an accurate VIN start threshold. To enable the converter
all the time, tie RUN to VIN. See the Operation section of
this data sheet for more guidance.
VCC (Pin 5/Pin 7): Output Voltage of the Internal 4V
Voltage Regulator. This is the supply pin for the internal
circuitry. Bypass this output with a minimum of 4.7µF
ceramic capacitor. This internal regulator is powered by
VIN or EXTVCC. Note that VCC should not be back-driven.
VCC can be used to power external circuitry as long as
the peak load current doesn’t exceed 2mA. Note that this
added load will increase the minimum required operating
VIN voltage by up to 60mV.
NC (Pin 17, QFN Only): Unused. This pin should be
grounded.
MPPC (Pin 6/Pin 8): Maximum Power Point Control
Programming Input. Connect this pin to a resistor divider
from VIN to ground to enable MPPC functionality. If the
divider voltage drops below 1.0V (typical), the inductor
current will be reduced to servo VIN to the programmed
minimum voltage, as set by the divider. Note that this pin
is very noise sensitive, therefore minimize trace length and
stray capacitance. Refer to the Applications Information
section of this data sheet for more detail on programming
the MPPC. If this function is not needed, tie the pin to VCC.
GND (Pins 7-8, Exposed Pad Pin 21/Pin 1, Exposed Pad
Pin 17): Ground. Provide a short direct PCB path between
GND and the ground plane that the exposed pad is soldered
to. The exposed pad must be soldered to the PCB ground
plane. It serves as a power ground connection, and as a
means of conducting heat away from the die.
FB (Pin 9/Pin 9 (LTC3130)): Feedback input to the error
amplifier. Connect to a resistor divider from VOUT to ground.
The output voltage can be adjusted from 1.0V to 25V by:
 R1
VOUT = 1.00V •  1+ 
 R2 
(Re fer to Figure 2)
Note that this pin is very noise sensitive, therefore minimize
trace length and stray capacitance. Please refer to the
Applications Information section of this data sheet for more
detail on setting the FB voltage divider, and the optional
use of an optional feed-forward capacitor.
VS2 (Pin 9/Pin 9 (LTC3130-1)): Output Voltage Select Pin.
Connect this pin to ground or VCC to program the output
voltage (see Table 1). This pin can also be dynamically driven
by any logic signal that satisfies the specified thresholds.
ILIM (Pin 10/Pin 10 (LTC3130)): Programming pin to
select between 250mA or 660mA average minimum inductor current limit. Please see the Maximum Output Current
curve in the Typical Performance Characteristics section.
ILIM = Low (ground): Sets the average inductor current
limit to 250mA (minimum) for low current applications
ILIM = High (tie to VCC): Sets the average inductor
current limit to 660mA (minimum)
This pin can also be dynamically driven by any logic signal
that satisfies the specified thresholds.
3130f
For more information www.linear.com/LTC3130
11
LTC3130/LTC3130-1
PIN FUNCTIONS
(QFN/MSOP)
VS1 (Pin 10/Pin 10 (LTC3130-1)): Output Voltage Select
Pin. Connect this pin to ground or VCC to program the
output voltage (see Table 1). This pin can also be dynamically driven by any logic signal that satisfies the specified
thresholds.
Table 1. VOUT Program Settings for the LTC3130-1
VS2
VS1
VOUT
0
0
1.8V
0
VCC
3.3V
VCC
0
5.0V
VCC
VCC
12V
MODE (Pin 11/Pin 11): Mode Select Pin.
MODE = Low (ground): Enables automatic Burst Mode
operation
MODE = High (tie to VCC): Fixed frequency PWM
operation
This pin can also be dynamically driven by any logic signal
that satisfies the specified thresholds. There is an internal
3MΩ pull-down resistor connected to MODE once switching is enabled, to prevent it from floating.
EXTVCC (Pin 12/Pin 12): Second Input to the Internal
VCC Regulator. This pin can be tied to VOUT or another
voltage between 3V and 25V. If this input is used, it will
power the IC, reducing the quiescent current draw on
VIN in buck applications and allowing the converter to
operate from a VIN voltage down to 1V or less. A 4.7µF
decoupling capacitor is recommended on this pin unless
it is tied directly to the VOUT decoupling capacitor. If not
used, this pin should be grounded.
12
PGOOD (Pin 13/Pin 13): Open-drain output that pulls to
ground when FB (LTC3130) or VOUT (LTC3130-1) drops
too far below its regulated voltage. Connect a pull-up
resistor from this pin to a positive supply. Note that if a
supply voltage is present on VIN or EXTVCC, this pin will
be forced low in shutdown or UVLO.
VOUT (Pin 14/Pin 14): Output Voltage of the Converter.
Connect a minimum value of 4.7µF ceramic capacitor
from this pin to the ground plane. See the Applications
Information section of this data sheet for guidance.
BST2 (Pin 16/Pin 15): Boot-Strapped Floating Supply for
High Side NMOS Gate Drive. Connect to SW2 through a
22nF capacitor, as close to the part as possible.
SW2 (Pin 15/Pin 16): Switch Pin. Connect to the other
side of the inductor. Keep PCB trace lengths as short and
wide as possible to reduce EMI and parasitic resistance.
PGND (Pins 18-19)/(Pin 1): Power Ground. Provide a short
direct PCB path between PGND and the ground plane.
SW1 (Pin 20/Pin 3): Switch Pin. Connect to one side of
the inductor. Keep PCB trace lengths as short and wide as
possible to reduce EMI and parasitic resistance.
3130f
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
LTC3130 BLOCK DIAGRAM
PVIN
EXTVCC
VIN
BST
SW1
SW2
BST2
VREF
VCC_GD
LDO
VCC
1.05V
1.0V
VREF_GD
B
DRIVER
VSENSE
C
DRIVER
START
+
–
VSENSE
+
–
1.2A
ON
+
–
IPK
UV
LOGIC
FB
0.7V
VSENSE
ENABLE
VSENSE
50mA
MPPC
MODE
DRIVER
D
+
–
1.0V
RESET
IZERO
THERMAL
SHUTDOWN
+
–
SOFT-START
3M
VCC_GD
+
–
100mV
–
+
+
–
0.6V
A
VC
+
–
RUN
DRIVER
VOUT
ISENSE
4V
VREF
VOUT
VCC
VCC
+
–
VIN
1.0V
OSC
–
+
600mA
SLEEP
GND
200mA
PGND
CLAMP
–7.5%
–
+
PGOOD
ILIM
3130 BD
VCC
3130f
For more information www.linear.com/LTC3130
13
LTC3130/LTC3130-1
LTC3130-1 BLOCK DIAGRAM
PVIN
EXTVCC
VIN
BST
SW1
SW2
BST2
VCC
1.0V
VCC_GD
LDO
VCC
1.05V
DRIVER
B
VSENSE
C
VS2
DRIVER
VOUT
SELECT
INPUTS
START
+
–
VSENSE
+
–
1.2A
ON
+
–
IPK
UV
LOGIC
0.7V
VSENSE
ENABLE
VSENSE
50mA
MPPC
MODE
VS1
DRIVER
+
–
1.0V
RESET
IZERO
THERMAL
SHUTDOWN
100mV
–
+
+
–
PWM
SOFT-START
3M
VCC_GD
+
–
+
–
0.6V
D
VC
+
–
RUN
A
ISENSE
1.0V
VREF_GD
VOUT
VCC
DRIVER
4V
VREF
VOUT
+
–
VIN
FB
1.0V
OSC
600mA
SLEEP
GND
–
+
CLAMP
–7.5%
–
+
PGOOD
PGND
31301 BD
14
3130f
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
OPERATION
INTRODUCTION
The LTC3130/LTC3130-1 are 1.6µA quiescent current,
monolithic, current mode, buck-boost DC/DC converters
that can operate over a wide input voltage range of 0.6V
(2.4V to start) to 25V and provide up to 600mA to the
load. The LTC3130 has a FB pin for programming VOUT
anywhere from 1V to 25V, while the LTC3130-1 features
four fixed, user-selectable output voltages which can be
selected using the two digital programming pins. Internal,
low RDS(ON) N-channel power switches reduce solution
complexity and maximize efficiency. A proprietary switch
control algorithm allows the buck-boost converter to
maintain output voltage regulation with input voltages that
are above, below or equal to the output voltage. Transitions between the step-up or step-down operating modes
are seamless and free of transients and sub-harmonic
switching, making this product ideal for noise sensitive
applications. The LTC3130/LTC3130-1 operate at a fixed
nominal switching frequency of 1.2MHz, which provides
an ideal trade-off between small solution size and high
efficiency. Current mode control provides inherent input
line voltage rejection, simplified compensation and rapid
response to load transients.
Burst Mode capability is included in the LTC3130/
LTC3130‑1 and is user-selected via the MODE pin. In
Burst Mode operation, exceptional light-load efficiency is
achieved by operating the converter only when necessary
to maintain voltage regulation. The Burst Mode quiescent
current is a miserly 1.6µA. When Burst Mode operation
is selected, the converter automatically switches to fixed
frequency PWM mode at higher loads. (Please refer to the
Typical Performance Characteristic curves for the mode
transition point at different input and output voltages.)
If the application requires extremely low noise under all
load conditions, continuous PWM operation can also be
selected via the MODE pin by pulling it high.
A MPPC (maximum power point control) function is also
provided that prevents the converter from pulling enough
current to drop VIN below a user-programmed threshold
under load. This servos the input voltage of the converter
to a programmable point for maximum power extraction
when operating from various non-ideal power sources
such as photovoltaic cells.
The LTC3130/LTC3130-1 also feature an accurate RUN
comparator threshold with hysteresis, allowing the
buck/boost DC/DC converter to turn on and off at userprogrammed VIN voltage thresholds. With a wide voltage
range, 1.6µA Burst Mode current and programmable
RUN and MPPC pins, these highly integrated monolithic
converters are well suited for many diverse applications.
PWM MODE OPERATION
If the MODE pin is high (or if the load current on the converter is high enough to command PWM mode operation
with MODE low), the LTC3130/LTC3130-1 operate in a
fixed 1.2MHz PWM mode using an internally compensated
average current mode control loop. PWM mode minimizes
output voltage ripple and yields a low noise switching
frequency spectrum. A proprietary switching algorithm
provides seamless transitions between operating modes
and eliminates discontinuities in the average inductor
current, inductor ripple current and loop transfer function
throughout all modes of operation. These advantages
result in increased efficiency, improved loop stability and
lower output voltage ripple in comparison to the traditional
buck-boost converter.
Figure 1 shows the topology of the power stage which is
comprised of four N-channel DMOS switches and their
associated gate drivers. In PWM mode operation both
switch pins transition on every cycle independent of the
input and output voltages. In response to the internal
control loop command, an internal pulse width modulator
generates the appropriate switch duty cycle to maintain
regulation of the output voltage.
CBST1
BST1
CBST2
L
PVIN
SW1
SW2 VOUT
BST2
VCC
VCC
A
D
VCC
VCC
B
PGND
C
PGND
Figure 1. Power Stage Schematic
LTC3130
3130 F01
3130f
For more information www.linear.com/LTC3130
15
LTC3130/LTC3130-1
OPERATION
When stepping down from a high input voltage to a lower
output voltage, the converter operates in buck mode and
switch D remains on for the entire switching cycle except
for the minimum switch low duration (typically 70ns). During the switch low duration, switch C is turned on which
forces SW2 low and charges the flying capacitor, CBST2.
This ensures that the switch D gate driver power supply
rail on BST2 is maintained. The duty cycle of switches A
and B are adjusted to maintain output voltage regulation
in buck mode.
If the input voltage is lower than the output voltage, the
converter operates in boost mode. Switch A remains on
for the entire switching cycle except for the minimum
switch low duration (typically 70ns). During the switch
low duration, switch B is turned on which forces SW1
low and charges the flying capacitor, CBST1. This ensures
that the switch A gate driver power supply rail on BST1 is
maintained. The duty cycle of switches C and D are adjusted
to maintain output voltage regulation in boost mode.
Oscillator
The LTC3130/LTC3130-1 operate from an internal oscillator with a nominal fixed frequency of 1.2MHz. This allows
the DC/DC converter efficiency to be maximized while still
using small external components.
Current Mode Control
The LTC3130/LTC3130-1 utilizes average current mode
control for the pulse width modulator. Current mode
control, both average and the better known peak method,
enjoy some benefits compared to other control methods
including: simplified loop compensation, rapid response
to load transients and inherent line voltage rejection.
Referring to the Block Diagrams, a high gain, internally
compensated transconductance voltage error amplifier
monitors VOUT through a voltage divider connected to the
FB pin (LTC3130) or via the internal VOUT voltage divider
(LTC3130-1). The error amplifier output is used by the
current mode control loop to command the appropriate
inductor current level. The inverting input of the internally
compensated average current amplifier is connected to
the inductor current sense circuit. The average current
amplifier’s output is compared to the oscillator ramps,
16
and the comparator outputs are used to control the duty
cycle of the switch pins on a cycle-by-cycle basis.
The voltage error amplifier makes adjustments to the current command as necessary to maintain VOUT in regulation.
The voltage error amplifier therefore controls the outer
voltage regulation loop. The average current amplifier
makes adjustments to the inductor current as directed
by the voltage error amplifier, and is commonly referred
to as the inner current loop amplifier.
The average current mode control technique is similar to
peak current mode control except that the average current
amplifier, by virtue of its configuration as an integrator,
controls average current instead of the peak current. This
difference eliminates the peak to average current error
inherent to peak current mode control, while maintaining
most of the advantages inherent to peak current mode
control.
The compensation components required to ensure proper
operation have been carefully selected and are integrated
within the LTC3130/LTC3130-1.
Inductor Current Sense and Maximum Average
Output Current
As part of the current control loop required for current
mode control, the LTC3130/LTC3130-1 include a pair
of current sensing circuits that measure the buck-boost
converter inductor current.
The voltage error amplifier output (VC) is internally clamped
to an accurate threshold. Since the average inductor current
is proportional to VC, the clamp level sets the maximum
average inductor current that can be programmed by the
inner current loop. Taking into account the current sense
amplifier’s gain, the maximum average inductor current is approximately 850mA typical (660mA minimum,
assuming the ILIM pin is pulled high for the LTC3130).
In buck mode, the output current is approximately equal
to 90% of the inductor current IL (due to the forced low
time of the B and C switches, where no current is delivered
to the output):
IOUT(BUCK) ≈ 0.9 • IL
3130f
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LTC3130/LTC3130-1
OPERATION
In boost mode, the output current is related to average
inductor current and duty cycle by:
IOUT(BOOST)
 V 
≈ IL •  IN  • η
 VOUT 
Since the output current in boost mode is reduced by the
step-up ratio of VIN/VOUT, the output current rating in buck
mode is always greater than in boost mode. Also, because
boost mode operation requires a higher inductor current
for a given output current compared to buck mode, the
efficiency (η) in boost mode will generally be lower due
to higher IL2 • RDS(ON) losses in the power switches. This
will further reduce the output current capability in boost
mode. In either operating mode, however, the inductor
peak-to-peak ripple current does not play a major role
in determining the output current capability, unlike peak
current mode control.
The LTC3130/LTC3130-1 measure and control average
inductor current, and therefore, the inductor ripple current magnitude has little effect on the maximum current
capability (in contrast to an equivalent peak current mode
converter). Under most conditions in buck mode, the
LTC3130/LTC3130-1 are capable of providing a minimum
of 600mA to the load. Refer to the Typical Performance
Characteristics section for more details. In boost mode,
as described previously, the output current capability is
related to the boost ratio. For example, for a 5V VIN to 15V
output application, the LTC3130/LTC3130-1 can provide
up to 150mA typical to the load. Refer to the Typical
Performance Characteristics section for more detail on
output current capability.
Programming VOUT (LTC3130)
The output voltage of the LTC3130 is programmed using
an external resistor divider from VOUT to ground with the
divider tap connected to the FB pin, as shown in Figure 2,
according to the equation:
 R1
VOUT = 1.00V •  1+ 
 R2 
(Re fer to Figure 2)
The output voltage can be set anywhere from 1.0V to 25V.
An optional feed-forward capacitor can be added in parallel
with R1 (as shown in Figure 2) to reduce Burst Mode ripple
and improve transient response of the voltage loop. The
typical feed-forward capacitor value can be calculated by:
CFF (pF ) =
40
R1 (Meg)
In some applications, where the voltage-loop bandwidth
is high, it may prove beneficial to add a resistor in series
with the feed-forward capacitor to limit the high frequency gain. The value isn’t critical, and resistor values of
VOUT
COUT
LTC3130
R1
CFF OPTIONAL
FEED-FORWARD
RFF
FB
R2
GND
3130 F02
Figure 2. VOUT Feedback Divider (Showing Optional
Feed-Forward Capacitor)
approximately R1/20 are generally recommended.
VOUT Programming Pins (LTC3130-1)
The LTC3130-1 has a precision internal voltage divider
on VOUT, eliminating the need for high value external
feedback resistors. This not only eliminates two external
components, it minimizes no-load quiescent current
by using very high resistance values that would not be
practical when used externally due to the effects of noise
and board leakages that would cause VOUT regulation errors. The tap point on this divider is digitally selected by
using the VS1 and VS2 pins to program one of four fixed
output voltages.
The VS1 and VS2 pins can be grounded or connected
to VCC to select the desired output voltage, according to
Table 1. They can also be driven dynamically from external
logic signals, as long as the pin’s specified logic levels are
satisfied and the absolute maximum ratings for the pins
are not exceeded.
3130f
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17
LTC3130/LTC3130-1
OPERATION
Note that driving VS1 or VS2 to a logic high that is below
the VCC voltage can result in an increase of up to 1µA of
current draw from VCC per VS pin. This does not occur in
shutdown or if VCC is below its UVLO threshold, in which
case these inputs are disabled and will not cause any extra
current draw.
Table 1. VOUT Program Settings for the LTC3130-1
VS2
VS1
VOUT
0
0
1.8V
0
VCC
3.3V
VCC
0
5.0V
VCC
VCC
12V
Programming the ILIM Threshold (LTC3130 only)
The LTC3130 has two average current limit settings,
which are set by the ILIM pin. If ILIM is pulled high (tied
to VCC), the average inductor current limit will be set to
660mA (minimum). If the ILIM pin is pulled low (tied to
ground), the average inductor current limit will be reduced
to 250mA (minimum). This setting can be used in low
power applications to reduce the maximum current draw
from sources that may suffer excessive voltage drop at
the full 600mA current limit setting, or to simply reduce
the maximum output current.
VOUT Undervoltage and Foldback Current Limit
The LTC3130/LTC3130-1 include a foldback current limit
feature to reduce power dissipation into a shorted output.
When VOUT is less than 0.7V (typical), the average current
limit is reduced to about half of its normal value. In the
case of the LTC3130 with the ILIM pin set low, the average
inductor current limit has already been cut in half and will
not be further reduced during undervoltage.
Overload Peak Current Limit
The LTC3130/LTC3130-1 also have peak overload current
(IPEAK) and zero current (IZERO) comparators. The IPEAK
current comparator turns off switch A for the remainder
of the switching cycle if the inductor current exceeds the
maximum threshold of 1.3A (typical). An inductor current
18
level of this magnitude may occur during a fault, such as
an output short circuit, or possibly for a few cycles during large load or input voltage transients. Note that it may
also occur if there is excessive inductor ripple current (or
inductor saturation) due to an improperly sized inductor.
Note that if a peak current limit is reached while VOUT is
also less than 0.7V typical (which would be indicative of
a shorted output), a soft-start cycle will be triggered.
IZERO Comparator
The LTC3130/LTC3130-1 feature near discontinuous
inductor current operation at light output loads by virtue
of the IZERO comparator circuit. By limiting the reverse
current magnitude in PWM mode, a balance between low
noise operation and improved efficiency at light loads is
achieved. The IZERO threshold is set near the zero current
level in PWM mode, and as a result the reverse current
magnitude will be a function of inductance value and output voltage due to the comparator’s propagation delay. In
general, higher output voltages and lower inductor values
will result in increased peak reverse current.
In automatic Burst Mode operation (MODE pin low), the
IZERO threshold is increased so that reverse inductor current does not normally occur. This maximizes efficiency
at light loads.
Note that reverse current is also inhibited during softstart (regardless of the MODE pin setting) to prevent VOUT
discharge when starting up into pre-biased outputs.
Burst Mode OPERATION
When the MODE pin is held low, the LTC3130/LTC3130-1
are configured for automatic Burst Mode operation. As a
result, the buck-boost DC/DC converter will operate with
normal continuous PWM switching above a predetermined
minimum output load and will automatically transition to
power saving Burst Mode operation below this output
load level. Refer to the Typical Performance Characteristics section of this data sheet to determine the Burst
Mode transition threshold for various combinations of
VIN and VOUT.
3130f
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LTC3130/LTC3130-1
OPERATION
If MODE is low, at light output loads, the LTC3130/
LTC3130‑1 go into a standby or sleep state when the
output voltage achieves its nominal regulation level. The
sleep state halts PWM switching and powers down all
non-essential functions of the IC, significantly reducing
the quiescent current of the converter to just 1.6µA typical.
This greatly improves overall power conversion efficiency
when the output load is light. Since the converter is not
operating in sleep, the output voltage will slowly decay at a
rate determined by the output load current and the output
capacitor value. When the output voltage has decayed by a
small amount, the LTC3130/LTC3130-1 wake and resume
normal PWM switching operation until the voltage on VOUT
is restored to the previous level. If the load is very light,
the converter may only need to switch for a few cycles to
restore VOUT and may sleep for extended periods of time,
significantly improving efficiency. If the load is suddenly
increased above the burst transition threshold, the part
will automatically resume continuous PWM operation until
the load is once again reduced.
Note that Burst Mode operation is inhibited until soft-start
is done, the MPPC pin is greater than 1.05V and VOUT has
reached 95% of regulation.
Soft-Start
The LTC3130/LTC3130-1 soft-start circuit minimizes input
current transients and output voltage overshoot on initial
power up. The required timing components for soft-start
are internal to the IC and produce a nominal average current limit soft-start duration of approximately 12ms. The
internal soft-start circuit slowly ramps the error amplifier
output. In doing so, the maximum average inductor current
is also slowly increased, starting from zero. Soft-start is
reset if the RUN pin drops below the accurate run threshold,
VCC drops below its UVLO threshold, a thermal shutdown
occurs, or a peak current limit occurs while VOUT is less
than 0.7V typical.
Note that because the average current limit is being softstarted, the VOUT rise time will be load dependent, and is
typically less that 12ms.
VCC Regulator and EXTVCC Input
An internal low dropout regulator (LDO) generates a nominal 4V VCC rail from VIN, or from EXTVCC if a valid EXTVCC
voltage is present. The VCC rail powers the internal control
circuitry and the gate drivers of the LTC3130/LTC3130-1.
The VCC regulator is enabled even in shutdown, but will
regulate to a lower voltage. The VCC regulator includes
current-limit protection to safeguard against accidental
short-circuiting of the VCC rail. VCC should be decoupled
with a 4.7µF ceramic capacitor located close to the IC.
During start-up, the IC will choose the higher of VIN or
EXTVCC to generate VCC. Once VCC is above its rising UVLO
threshold, EXTVCC will continue to be used if it is above
3.0V typical, otherwise VIN will be used. This allows startup from low VIN sources (in applications where a valid
EXTVCC voltage is present), while minimizing LDO power
dissipation after start-up in applications where VIN may
be much higher than VCC.
Use of the EXTVCC input allows the converter to operate
from VIN voltages less than 1V, as long as EXTVCC is held
in its operating range of 3.0V minimum and 25V maximum.
If EXTVCC is tied to VOUT in buck applications, it will also
reduce the input current drawn from VIN, thereby increasing
converter efficiency, especially at light loads.
If an independent source, such as a battery or another
supply rail, is used to power EXTVCC, then the IC can start
up and operate at any input voltage, from 25V down to
(theoretically) 0V (assuming the RUN pin is held above
1.05V). In practice, the minimum VIN voltage capability
will be application specific, determined by the required
output voltage and output current of the converter. Due
to the rapid drop in efficiency at very low input voltages,
the practical VIN limit is usually around 0.6V, assuming a
low resistance source, and that the step-up ratio to VOUT
doesn’t become duty cycle limited. Refer to the Typical
Performance Characteristic curves for the output voltage
and current capability versus VIN.
If not used, EXTVCC should be grounded.
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19
LTC3130/LTC3130-1
OPERATION
Undervoltage Lockout (UVLO)
The VCC UVLO has a falling voltage threshold of 2.175V
(typical). If the VCC voltage falls below this threshold, IC
operation is disabled until VCC rises above 2.30V (typical).
Therefore, if a valid voltage source is not present on
EXTVCC, the minimum VIN for the part to start up is 2.30V
(typical).
Note that until VCC is above the UVLO threshold, the part
will remain in a low quiescent current state (1.4µA typical).
This facilitates start-up from very weak sources.
RUN Pin Comparator
When RUN is driven above its logic threshold (0.6V typical), the internal voltage reference and the PGOOD circuit
are enabled (assuming VCC is above 2.30V typical). If the
voltage on RUN is increased further so that it exceeds
the RUN comparator’s accurate rising threshold (1.05V
typical), all functions of the buck-boost converter will be
enabled and a start-up sequence will ensue. The RUN pin
comparator has 100mV of hysteresis, so operation will
be inhibited if the pin drops below 0.95V.
Therefore, with the addition of an optional resistor divider
as shown in Figure 3, the RUN pin can be used to establish user-programmable turn-on and turn-off (UVLO)
thresholds. This feature can be utilized to minimize battery
drain below a programmed input voltage, or to operate the
converter in a hiccup mode from very low current sources.
LTC3130
VIN
1.05V
R3
–
+
ACCURATE THRESHOLD
ENABLE SWITCHING
RUN
R4
0.6V
+
–
ENABLE VREF
AND PGOOD
LOGIC THRESHOLD
3130 F03
Figure 3. Accurate RUN Pin Comparator
20
If RUN is brought below the accurate comparator falling
threshold, the buck-boost converter will inhibit switching,
but the VCC regulator and control circuitry will remain
powered. In this state, the typical VIN quiescent current is
only 1.4µA, in order to completely shut down the IC and
reduce the VIN current to 500nA (typical), it is necessary
to ensure that RUN is brought below its minimum low
logic threshold of 0.2V.
RUN can be tied directly to VIN to continuously enable the
IC when the input supply is present. Also note that RUN
can be driven above VIN or VOUT as long as it stays within
the absolute maximum rating of 25V.
The converter is enabled when the voltage on RUN exceeds
1.05V (nominal). Therefore, the turn-on voltage threshold
on VIN is given by:
 R3 
VIN(TURNON) = 1.05V •  1+ 
 R4 
Once the converter is enabled, the RUN comparator
includes a built-in hysteresis of 100mV, so that the turnoff threshold will be :
 R3 
VIN(TURNOFF) = 0.95V •  1+ 
 R4 
The RUN comparator is designed to be relatively noise
insensitive, but there may be cases due to PCB layout,
very large value resistors for R3 and R4, or proximity
to noisy components where noise pickup is unavoidable
and may cause the turn-on or turn-off of the IC to be
intermittent. In these cases, a small filter capacitor can
be added across R4.
PGOOD Comparator
The LTC3130/LTC3130-1 provide an open-drain PGOOD
output that pulls low if FB (LTC3130) or VOUT (LTC3130‑1)
falls more than 7.5% (typical) below its programmed
value. When VOUT rises to within 5% (typical) of its
programmed value, the internal PGOOD pull-down will
turn off and PGOOD will go high if an external pull-up
resistor has been provided. An internal filter prevents
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LTC3130/LTC3130-1
OPERATION
nuisance trips of PGOOD due to short transients on VOUT.
PGOOD can be pulled up to any voltage, as long as the
absolute maximum rating of 25V is not exceeded, and
as long as the absolute maximum sink current rating of
12mA is not exceeded when PGOOD is low.
The MPPC divider resistor values can be in the MΩ range
so as to minimize the input current in very low power applications. However, stray capacitance and noise pickup
on the MPPC pin must also be minimized. If the MPPC
function is not required, the MPPC pin should be tied to VCC.
Note that PGOOD will be driven low if VCC is below its UVLO
threshold or if the part is in shutdown (RUN below its logic
threshold). PGOOD is not affected by the accurate RUN
threshold. Therefore, if PGOOD is pulled up to VIN or VCC,
this will add to the VIN quiescent current in shutdown and
UVLO, when PGOOD is low. For the lowest possible VIN
current in shutdown or UVLO, PGOOD should be pulled
up to VOUT or some other source.
Beware of adding a noise filter capacitor to the MPPC pin,
as the added filter pole may cause the MPPC control loop
to be unstable.
Maximum Power Point Control (MPPC)
The MPPC input of the LTC3130/LTC3130-1 can be used
with an optional external voltage divider to dynamically
adjust the commanded inductor current in order to maintain a minimum input voltage when using high resistance
sources, such as photovoltaic panels, so as to maximize
input power transfer and prevent VIN from dropping too
low under load.
Referring to Figure 4, the MPPC pin is internally connected
to the noninverting input of a gm amplifier, whose inverting input is connected to the 1.0V reference. If the voltage
at MPPC, using the external voltage divider, falls below
the reference voltage, the output of the amplifier pulls
the internal VC node low. This reduces the commanded
average inductor current so as to reduce the input current
and regulate VIN to the programmed minimum voltage,
as given by:
Note that because Burst Mode operation will be inhibited
if the MPPC loop takes control, the converter will be operating in fixed frequency mode, and will therefore require
a minimum of about 6mA of continuous input current to
operate. For operation from weaker sources, such as small
indoor solar panels, refer to the Applications Information
section to see how the RUN pin may be programmed to
control the converter in a hysteretic manner while providing an effective MPPC function by maintaining VIN at the
desired voltage. This technique can be used with sources
as weak as 3µA (enough to power the IC in UVLO and the
external RUN divider).
VIN
RS
CIN
R5
+
–
VSOURCE
MPPC
+
–
R6
VIN
LTC3130
1.0V
FB
+
–
VC
CURRENT
COMMAND
VOLTAGE
ERROR AMP
3130 F04
 R5 
VIN(MPPC) = 1.00V •  1+ 
 R6 
Figure 4. MPPC Amplifier with External Resistor Divider
Note that external compensation should not be required
for MPPC loop stability if the input filter capacitor, CIN,
is at least 22µF.
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21
LTC3130/LTC3130-1
APPLICATIONS INFORMATION
A standard application circuit for the LTC3130-1 is shown
on the front page of this data sheet. There are numerous
other application examples for both the LTC3130-1 and
LTC3130 shown in the Typical Applications section of
this data sheet.
The appropriate selection of external components is dependent upon the required performance of the IC in each
particular application given considerations and trade-offs
such as PCB area, input and output voltage range, output
voltage ripple, transient response, required efficiency,
thermal considerations and cost. This section of the data
sheet provides some basic guidelines and considerations
to aid in the selection of external components and the design of the applications circuit, as well as more application
circuit examples.
VCC Capacitor Selection
The VCC output of the LTC3130/LTC3130-1 is generated
from VIN or EXTVCC by a low dropout linear regulator. The
VCC regulator has been designed for stable operation with
a wide range of output capacitors. For most applications,
a low ESR capacitor of at least 4.7µF should be used. The
capacitor should be located as close to the VCC pin as possible and connected to the VCC pin and ground through the
shortest traces possible. VCC is the regulator output and
is also the internal supply pin for the IC control circuitry
as well as the gate drivers and boost rail charging diodes.
Inductor Selection
The choice of inductor used in LTC3130/LTC3130-1
application circuits influences the maximum deliverable
output current, the converter bandwidth, the magnitude
of the inductor current ripple and the overall converter
efficiency. The inductor must have a low DC series resistance or output current capability and efficiency will be
compromised. Larger inductor values reduce inductor
current ripple but do not increase output current capability
as is the case with peak current mode control. Larger value
inductors also tend to have a higher DC series resistance
22
for a given case size, which will have a negative impact on
efficiency. Larger values of inductance will also lower the
right half plane (RHP) zero frequency when operating in
boost mode, which can compromise loop stability. Nearly
all LTC3130/LTC3130-1 application circuits deliver the
best performance with an inductor value between 3.3µH
and 15µH, depending on VIN and VOUT. Buck mode only
applications can use the larger inductor values as they
are unaffected by the RHP zero, while mostly boost applications generally require inductance on the low end of
this range depending on how large the step-up ratio is.
Regardless of inductor value, the saturation current rating
should be selected such that it is greater than the worst-case
average inductor current plus half of the ripple current. The
peak-to-peak inductor current ripple for each operational
mode can be calculated from the following formula, where
f is the switching frequency (1.2MHz), L is the inductance
in µH and tLOW is the switch pin minimum low time in
µs. The switch pin minimum low time is typically 0.07µs.
∆IL(P-P)(BUCK) =
VOUT  VIN – VOUT   1

 – tLOW  Amps


L 
VIN
 f
∆IL(P-P)(BOOST) =
VIN  VOUT – VIN   1

 – tLOW  Amps


L  VOUT  f
It should be noted that the worst-case peak-to-peak inductor ripple current occurs when the duty cycle in buck
mode is minimum (highest VIN) and in boost mode when
the duty cycle is 50% (VOUT = 2 • VIN). As an example, if
VIN (minimum) = 2.5V and VIN (maximum) = 15V, VOUT
= 5V and L = 10µH, the peak-to-peak inductor ripples at
the voltage extremes (15V VIN for buck and 2.5V VIN for
boost) are:
Buck = 251mA peak-to-peak
Boost = 94mA peak-to-peak
One-half of this inductor ripple current must be added to
the highest expected average inductor current in order to
select the proper saturation current rating for the inductor.
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LTC3130/LTC3130-1
APPLICATIONS INFORMATION
To minimize core losses and to prevent high inductor current ripple from tripping the peak current limit before the
average current limit is reached, an inductor value with a
�IL of less than 500mA P-P should be chosen. For loads
that operate well below current limit, higher inductor ripple
can be tolerated to allow the use of a lower value inductor.
To avoid the possibility of inductor saturation during load
transients, an inductor with a saturation current rating
of at least 1200mA is recommended for all applications
(unless the ILIM pin of the LTC3130 is set low, in which
case a 650mA rated inductor may be used).
Note that in boost mode, especially at large step-up ratios, the output current capability is often limited by the
total resistive losses in the power stage. These losses
include switch resistances, inductor DC resistance and
PCB trace resistance. Avoid inductors with a high DC
resistance (DCR) as they can degrade the maximum output current capability from what is shown in the Typical
Performance Characteristics section and from the Typical
Application circuits.
As a guideline, the inductor DCR should be significantly
less than the typical power switch resistance of 350mΩ.
The only exceptions are applications that have a maximum output current much less than what the LTC3130/
LTC3130-1 are capable of delivering. Generally speaking,
inductors with a DCR in the range of 0.05Ω to 0.15Ω are
recommended. Lower values of DCR will improve the efficiency at the expense of size, while higher DCR values
will reduce efficiency (typically by a few percent) while
allowing the use of a physically smaller inductor.
Different inductor core materials and styles have an impact
on the size and price of an inductor at any given current
rating. Shielded construction is generally preferred as it
minimizes the chances of interference with other circuitry.
The choice of inductor style depends upon the price, sizing,
and EMI requirements of a particular application.
Table 2 provides a wide sampling of inductor families from
different manufacturers that are well suited to LTC3130/
LTC3130-1 applications. However, be sure to check the
current rating and DC resistance for the particular value
you need, as not all of the inductor values in a given family
will be suitable.
Table 2. Recommended Inductors
VENDOR
PART NUMBER FAMILY
Coilcraft
coilcraft.com
EPL3015, LPS3314, LPS4012, LPS4018,
XFL3012, XFL4020, MSS4020
Coiltronics
cooperindustries.com
SD3814, SD3118, SD52
Murata
murata.com
LQH43P, LQH44P
Sumida
sumida.com
CDRH2D18, CDRH3D14, CDRH3D16,
CDRH4D14
Taiyo-Yuden
t-yuden.com
NR3012T, NR3015T, NRS4012T, NR4018T
TDK
tdk.com
VLF252015MT, VLF302510MT,
VLF302512MT, VLS3015ET, VLCF4018T,
VLCF4020T, SPM4012T
Toko
tokoam.com
DB318C, DB320C, DEM2815C, DEM3512C,
DEM3518C
Wurth
we-online.com
WE-TPC 2818, WE-TPC 3816
Recommended maximum inductor values and minimum
output capacitor values, for different output voltage
ranges are given in Table 3 as a guideline. These values
were chosen to minimize inductor size while ensuring
loop stability over the entire load range of the converter.
Table 3. Recommended Inductor and
Output Capacitor Values
MINIMUM RECOMMENDED OUTPUT CAPACITANCE (μF)
VOUT
(V)
LMAX LTC3130-1/LTC3130
LTC3130
(μH) WITH FEED FORWARD PWM AND NO FEED-FORWARD
1 – 2.4
4.7
40
20
2.5 – 3.9
6.8
30
15
4 – 6.5
10
20
10
6.6 – 14
15
20
10
14 – 25
15
10
5
Note that many applications will be able to use a lower
inductor value, depending on the input voltage range and
resulting inductor current ripple. Lower inductor values
will also allow the use of a smaller output capacitor value
without compromising loop stability.
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23
LTC3130/LTC3130-1
APPLICATIONS INFORMATION
Output Capacitor Selection
A low effective series resistance (ESR) output capacitor
of 10µF minimum should be connected at the output of
the buck-boost converter in order to minimize output voltage ripple. Multilayer ceramic capacitors are an excellent
option as they have low ESR and are available in small
footprints. The capacitor value should be chosen large
enough to reduce the output voltage ripple to acceptable
levels. Neglecting the capacitor’s ESR and ESL (effect
series inductance), the peak-to-peak output voltage ripple
can be calculated by the following formula, where f is the
frequency in MHz (1.2MHz), COUT is the capacitance in µF,
tLOW is the switch pin minimum low time in µs (0.07µs)
and ILOAD is the output current in Amps:
∆VP-P(BUCK) =
ILOAD t LOW
∆VP-P(BOOST) =
COUT
Volts
ILOAD  VOUT – VIN + tLOW fVIN 
 Volts
fCOUT 
VOUT
Examining the previous equations reveal that the output
voltage ripple increases with load current and is generally higher in boost mode than in buck mode. Note that
these equations only take into account the voltage ripple
that occurs from the inductor current to the output being
discontinuous. They provide a good approximation of the
ripple at any significant load current but underestimate the
output voltage ripple at very light loads where the output
voltage ripple is dominated by the inductor current ripple.
In addition to the output voltage ripple generated across
the output capacitance, there is also output voltage ripple
produced across the internal resistance of the output
capacitor. The ESR-generated output voltage ripple is
proportional to the series resistance of the output capacitor
and is given by the following expressions where RESR is
24
the series resistance of the output capacitor and all other
terms as previously defined:
∆VP-P(BUCK) =
ILOADRESR
∆VP-P(BOOST) =
1– tLOW f
≅ ILOADRESR Volts
ILOADRESR VOUT
(
VIN 1– t LOW f
)
V 
≅ ILOADRESR  OUT  Volts
 VIN 
In most LTC3130/LTC3130-1 applications, an output
capacitor between 10µF and 47µF will work well. To minimize output ripple in Burst Mode operation, or transients
incurred by large step loads, values of 22µF or larger are
recommended.
Input Capacitor Selection
The PVIN pin carries the full inductor current, while the VIN
pin provides power to internal control circuits in the IC. To
minimize input voltage ripple and ensure proper operation of the IC, a low ESR bypass capacitor with a value of
at least 4.7µF should be located as close to the PVIN pin
as possible. The VIN pin should be bypassed with a 1μF
ceramic capacitor located close to the pin, and Kelvined
to “quiet side” of the primary VIN decoupling capacitor.
Do not tie the VIN pin directly to PVIN pin.
When powered through long leads or from a power source
with any significant resistance, an additional, larger value
bulk input capacitor may be required and is generally
recommended. In such applications, a 47µF to 100µF
low ESR electrolytic capacitor in parallel with the 4.7µF
ceramic capacitor generally yields a high performance,
low cost solution.
For applications using the MPPC feature, a minimum CIN
capacitor value of 22µF is recommended. Larger values
can be used without limitation.
3130f
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
APPLICATIONS INFORMATION
Recommended Input and Output Capacitor Types
The capacitors used to filter the input and output of the
LTC3130/LTC3130-1 must have low ESR and must be
rated to handle the AC currents generated by the switching
converter. This is important to maintain proper functioning
of the IC and to reduce output voltage ripple. There are
many capacitor types that are well suited to these applications including multilayer ceramic, low ESR tantalum,
OS-CON and POSCAP technologies. In addition, there
are certain types of electrolytic capacitors such as solid
aluminum organic polymer capacitors that are designed
for low ESR and high AC currents and these are also well
suited to some LTC3130/LTC3130-1 applications.
value capacitance or a higher voltage rated capacitor than
would ordinarily be required to actually realize the intended
capacitance at the operating voltage of the application. X5R
and X7R dielectric types are recommended as they exhibit
the best performance over the wide operating range and
temperature of the LTC3130/LTC3130-1. To verify that
the intended capacitance is achieved in the application
circuit, be sure to consult the capacitor vendor’s curve
of capacitance versus DC bias voltage.
Using the Programmable RUN Function to Operate
from Extremely Weak Input Sources
Beware of Capacitor DC Bias Effect
Another application of the programmable RUN pin is
that it can be used to operate the converter in a “hiccup”
mode from extremely weak sources. This allows operation
from sources that can only generate microamps of output
current, and would be far too weak to sustain normal
steady-state operation, even with the use of the MPPC
pin. Because the LTC3130/LTC3130-1 draw only 1.4µA
typical from VIN until they are enabled, the RUN pin can be
programmed to keep the ICs disabled until VIN reaches the
programmed voltage level. In this manner, the input source
can trickle-charge an input storage capacitor, even if it can
only supply microamps of current, until VIN reaches the
turn-on threshold set by the RUN pin divider. The converter
will then be enabled, using the stored charge in the input
capacitor to power the converter and bring up VOUT, until
VIN drops below the turn-off threshold, at which point the
converter will turn off and the process will repeat.
Ceramic capacitors are often utilized in switching converter applications due to their small size, low ESR and
low leakage currents. However, many ceramic capacitors
intended for power applications experience a significant
loss in capacitance from their rated value as the DC bias
voltage on the capacitor increases. It is not uncommon for
a small surface mount capacitor to lose more than 50%
of its rated capacitance when operated at even half of its
maximum rated voltage. This effect is generally reduced
as the case size is increased for the same nominal value
capacitor. As a result, it is often necessary to use a larger
This approach allows the converter to run from weak
sources as small, thin-film solar cells using indoor lighting. Although the converter will be operating in bursts, it
is enough to charge an output capacitor to power low duty
cycle loads, such as in wireless sensor applications, or
to trickle-charge a battery. In addition, note that the input
voltage will be cycling (with 10% ripple as set by the UVLO
hysteresis) about a fixed voltage, as determined by the
divider. This allows the high impedance source to operate about the programmed optimal voltage for maximum
power transfer.
The choice of capacitor technology is primarily dictated
by a trade-off between size, leakage current and cost. In
backup power applications, the input or output capacitor
might be a super or ultra capacitor with a capacitance
value measuring in the Farad range. The selection criteria
in these applications are generally similar except that voltage ripple is generally not a concern.
Some capacitors exhibit a high DC leakage current which
may preclude their consideration for applications that
require a very low quiescent current in Burst Mode operation. Note that ultra capacitors may have a rather high
ESR, therefore a 4.7µF (minimum) ceramic capacitor is
recommended in parallel, close to the IC pins.
3130f
For more information www.linear.com/LTC3130
25
LTC3130/LTC3130-1
APPLICATIONS INFORMATION
In these “trickle-charge” applications, a larger input capacitor is generally required. If the load on VOUT is extremely
light, such that the available steady-state input power can
sustain VOUT, then the input capacitor simply has to have
enough charge to bring VOUT into regulation before VIN
discharges below the falling UVLO threshold (assuming
that the goal is to charge up VOUT in a single “burst” and
then maintain VOUT regulation). In this case, the minimum
value required for CIN can be determined by:
CIN(MIN) >
COUT • VOUT 2
( η( V – (0.9 • V )))
IN
2
IN
2
where VIN is the programmed rising UVLO threshold and
η is the average conversion efficiency, given VIN and VOUT.
It can be seen that a larger COUT capacitor will require a
larger CIN capacitor to charge it.
The time required for the CIN capacitor to charge up to the
VIN rising UVLO threshold (starting from zero volts) is:
tCHARGE ( sec ) =
CIN (µF ) • VIN(UVLO)
(ICHARGE (µA ) – 1.4µA –ILEAK (µA ))
where ILEAK is the leakage of the input capacitor in µA at
the programmed VIN UVLO voltage.
For applications where VOUT must remain in regulation
during a pulsed load for a given period of time, the input
capacitor value required will be dictated by the programmed
VIN and VOUT, and the duration and magnitude of the output
load current, as given by:
CIN(MIN) >
IOUT • VOUT • 2 • t
( η( V – (0.9 • V )))
IN
2
IN
2
where CIN is in micro Farads, IOUT is the average load
current in milliamps for duration t in milliseconds. VIN
is the programmed rising UVLO threshold and η is the
average conversion efficiency, given VIN and VOUT. This
calculation assumes that the VOUT capacitor has already
been charged, and that the load on VOUT before and after
the load pulse is low enough as to be sustained by the
available steady-state input power.
26
For example, if VOUT is 5V, with a pulsed load of 25mA
for a duration of 5ms, and VIN has been programmed for
a rising UVLO threshold of 12V, then the minimum CIN
capacitor required, assuming a conversion efficiency of
85%, would be 53.7µF, so a 68µF input capacitor would
be recommended.
When using high value RUN pin divider resistors (in the
MΩ range) to minimize current draw on VIN, a small noise
filter capacitor may be necessary across the lower divider
resistor to prevent noise from erroneously tripping the
RUN comparator. The capacitor value should be minimized
(10pF may do) so as not to introduce a time delay long
enough for the input voltage to drop significantly below
the desired VIN threshold. Note that larger VIN decoupling
capacitor values will minimize this effect by providing more
holdup time on VIN.
Use of the EXTVCC Input
As discussed in the Operation section of this data sheet,
the LTC3130/LTC3130-1 include an EXTVCC input that can
be used to provide VCC for the IC, allowing start-up and/
or operation in applications where VIN is below the VCC
UVLO threshold, all the way down to less than 1V.
Possible sources that could be used to power the EXTVCC
input would include VOUT (if VOUT is programmed for at
least 3.15V and if VIN is at least 2.4V to start), or an independent voltage rail that may be available in the system,
or even a battery.
The requirements for the EXTVCC voltage are that it is a
minimum of 3.0V typical, and an absolute maximum of
25V. It must also be able to supply a minimum of 6mA
of current. If the source of EXTVCC is not very close to
the IC, then a decoupling capacitor of 4.7µF minimum is
recommended at the EXTVCC pin.
In the case of using a battery to power EXTVCC, the battery
life for continuous steady-state operation in fixed frequency
mode can be estimated by:
Battery Life (Hours) = Battery Capacity (mA-Hr)/6mA
3130f
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
APPLICATIONS INFORMATION
For example, a 3.6V battery with a capacity of 2600mA‑Hr
(2.6A-Hr) could power the IC continuously in fixed
frequency mode for ~433 hours (only about 18 days).
However, if the IC is in Burst Mode operation at light load,
the battery life time will be extended, possibly by orders
of magnitude (depending on the load) since the current
demand when the IC is sleeping will be only 1.6µA typical.
In shutdown, the current draw will be only 0.5µA typical.
For applications where VOUT will be greater than the battery
voltage, and at least 3.6V, a battery and a dual Schottky
diode can be used to get the part started at low VIN. After
start-up, the IC will be powered from VOUT, so there will
be no steady-state current draw on the battery. In this
case, the battery life may approach its shelf life (even in
continuous fixed frequency operation). In shutdown, there
will be about 0.5uA of current draw from the battery. An
example of this configuration is shown in Figure 5.
+
V
–
PVIN
VIN
1V TO 25V
EXTVCC
VOUT
VIN LTC3130/
LTC3130-1
RUN
COUT
VOUT
4V TO 25V
BAT54C
EXTVCC
SGND
4.7µF
+
3.6V
3031 F05
Figure 5. Using a Battery Just for Start-Up from Low VIN
Note that during start-up, when VCC is still in UVLO, the IC
chooses the higher of VIN or EXTVCC to power VCC (even
if EXTVCC is below 3.0V). After start-up however, when
VCC has risen above its rising UVLO threshold, the IC
will choose to use the EXTVCC input to power VCC only if
EXTVCC is above 3.0V, typical. This is done to avoid using
EXTVCC at a very low voltage when a higher voltage may
be available at VIN.
Therefore, there could be a situation where the IC would
switch between using EXTVCC during start-up, and VIN as
the source for VCC after start-up. However, if VIN is below
the UVLO threshold, VCC will drop and revert to using
EXTVCC again. This cycling will only occur if VIN is below
the UVLO falling threshold and EXTVCC is greater than the
UVLO rising threshold of 2.4V, but less than 3.0V (and
the part is enabled, with the RUN pin above the accurate
rising threshold). Note that during this time, the IC will be
periodically trying to start switching, as it goes in and out
of UVLO. If EXTVCC is held above 3.0V, this will not occur.
In applications where the VIN and EXTVCC voltages are
such that this scenario could occur, the RUN pin can be
used to monitor the EXTVCC input and inhibit operation
whenever EXTVCC is below 3.15V. An example of this is
shown in Figure 6.
EXTVCC
+
V
–
2M
VEXT
LTC3130
1.05V
RUN
–
+
ENABLE
SWITCHING
1M
3130 F06
Figure 6. Using the RUN Pin to Set the Minimum Voltage
for EXTVCC to 3.15V
Programming the MPPC Voltage
As discussed in the previous section, the LTC3130/
LTC3130-1 include an MPPC function to optimize performance when operating from voltage sources with relatively
high source resistance. Using an external voltage divider
from VIN, the MPPC function takes control of the average
inductor current when necessary to maintain a minimum
input voltage, as programmed by the user. Referring to
Figure 3:
 R5 
VIN(MPPC) = 1.0V •  1+ 
 R6 
This is useful for such applications as photovoltaic powered converters, since the maximum power transfer point
occurs when the photovoltaic panel is operated at about
75% of its open-circuit voltage. For example, when operating from a photovoltaic panel with an open-circuit voltage
of 5V, the maximum power transfer point will be when
the panel is loaded such that its output voltage is about
3.75V. Referring to Figure 4, choosing values of 2MΩ for
R5 and 732k for R6 will program the MPPC function to
regulate the maximum input current so as to maintain VIN
at a minimum of 3.73V (typical). Note that if the panel can
provide more power than the application requires, the input
voltage will rise above the programmed MPPC point. This
is fine as long as the input voltage doesn’t exceed 25V.
3130f
For more information www.linear.com/LTC3130
27
LTC3130/LTC3130-1
APPLICATIONS INFORMATION
For weak input sources with very high resistance (hundreds
of Ohms or more), the LTC3130/LTC3130-1 may still draw
more current than the source can provide, causing VIN to
drop below the UVLO threshold. For these applications,
it is recommended that the programmable RUN feature
be used, as described in a previous section.
MPPC Compensation and Gain
When using MPPC, there are a number of variables that
affect the gain and phase of the input voltage control loop.
Primarily these are the input capacitance, the MPPC resistor
divider ratio and the VIN source resistance. To simplify the
design of the application circuit, the MPPC control loop
in the LTC3130/LTC3130-1 is designed with a relatively
low gain, such that external MPPC loop compensation is
generally not required when using a VIN capacitor of at
least 22µF.
The gain from the MPPC pin to the internal control voltage
is about ten, and the gain of the internal control voltage
to average inductor current is about one. Therefore, a
change of 60mV a the MPPC pin will result in a change of
average inductor current of about 600mA, which is close
to the full current capability of the IC. So the programmed
input voltage will be maintained within about 6% over the
full current range of the IC (which may be more than that
required by the load).
Sources of Small Photovoltaic Panels
A list of companies that manufacture small solar panels
(sometimes referred to as modules or solar cell arrays),
suitable for use with the LTC3130/LTC3130-1 is provided
in Table 4.
Table 4. Small Photovoltaic Panel Manufacturers
Sanyo
panasonic.net
PowerFilm
powerfilmsolar.com
Ixys
Corporation
ixys.com
G24
Innovations
gcell.com
28
Thermal Considerations
The power switches of the LTC3130/LTC3130-1 are designed to operate continuously with currents up to the
internal current limit thresholds. However, when operating
at high current levels, there may be significant heat generated within the IC. As a result, careful consideration must
be given to the thermal environment of the IC in order to
provide a means to remove heat from the IC and ensure
that the LTC3130/LTC3130-1 is able to provide its full-rated
output current. Specifically, the exposed die attach pad
of both the QFN and MSE packages must be soldered to
a copper layer on the PCB to maximize the conduction of
heat out of the IC package. This can be accomplished by
utilizing multiple vias from the die attach pad connection
underneath the IC package to other PCB layer(s) containing
a large copper plane. A typical board layout incorporating
these concepts in show in Figure 7.
As described elsewhere in this data sheet, the EXTVCC
pin may be used to reduce the VCC power dissipation
term significantly in high VIN applications, lowering die
temperature and improving efficiency.
If the IC die temperature exceeds approximately 165°C,
overtemperature shutdown will be invoked and all switching
will be inhibited. The part will remain disabled until the die
temperature cools by approximately 10°C. The soft-start
circuit is re-initialized in overtemperature shutdown to
provide a smooth recovery when the IC die temperature
cools enough to resume operation.
Applications with Low VIN and VOUT
Applications which must operate from input voltages of
less that 3V and have an output voltage of 1.8V or less,
while operating at heavy loads, will benefit significantly
from the addition of Schottky diode from SW2 to VOUT.
Diodes such as an MBR0530 or equivalent are recommended for these applications.
3130f
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
APPLICATIONS INFORMATION
LTC3130
L1
CBST2
CBST1
RPGD
VIN
VOUT
GND
GND
CIN
PGOOD
ILIM
R2 R1
MODE
MPPC
RUN
COUT
CEXT
CVCC
LTC3130-1
L1
CBST2
CBST1
RPGD
VIN
VOUT
GND
GND
CIN
COUT
VS1
MODE
VS2
RUN
MPPC
PGOOD
CEXT
CVCC
8603 F07
Figure 7. Typical 2-Layer PC Board Layout (QFN Package Shown)
3130f
For more information www.linear.com/LTC3130
29
LTC3130/LTC3130-1
APPLICATIONS INFORMATION
22nF
VOC = 5V
VOP = 3.5V
VIN
BST1
PVIN
22nF
4.7µH
SW1
SW2
PV
PANEL
RUN
EXTVCC
LTC3130
1µF
VCC
2M
3.4M
PGOOD
MPPC
47µF
+
4.7µF
VIN
4.99M
BST2
VOUT
ILIM
+
100F
VOUT
4.4V
100k
100F
100k
FB
VCC
MODE
GND
PGND
4.7µF
1M
TECATE
TPL-100/22x45F
3130 F08
Figure 8. Outdoor Solar Panel Powered, 600mA Supercapacitor Charger Using MPPC
22nF
BST1
PVIN
VIN
22nF
10µH
SW1
SW2
VIN
3.6V
Li-SOCI2
+
RUN
10µF
VCC
1µF
LTC3130
BST2
VOUT
EXTVCC
PGOOD
MPPC
ILIM
1M
10µF
10pF
VOUT
24V
20mA
4.02M
200k
PGOOD
FB
VCC
MODE
GND
PGND
174k
4.7µF
3130 F09
Figure 9. Battery-Powered 24V Converter with 200mA ILIM to Limit Battery Droop
30
3130f
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
APPLICATIONS INFORMATION
22nF
BST1
PVIN
VIN
2.4V TO 25V
22nF
10µH
SW1
SW2
VIN
RUN
10µF
VCC
1µF
BST2
VOUT
10µF
EXTVCC
LTC3130
VOUT
15V
500mA
10pF (V > 15V)
IN
4.99M
249k
PGOOD
MPPC
ILIM
FB
VCC
MODE
GND
PGND
4.7µF
357k
3130 F10
Figure 10. Wide VIN Range 15V Converter with Burst Mode Operation
22nF
BST1
PVIN
VIN
0.95V TO 25V
(2.4V TO START)
22nF
6.8µH
SW1
SW2
22µF
VIN
RUN
10µF
VCC
LTC3130-1
EXTVCC
1M
MPPC
MODE
1µF
VOUT
5V
500mA
(VIN > 5V)
BST2
VOUT
PGOOD
PGOOD
VS1
VS2
VCC
GND
PGND
4.7µF
3130 F11
Figure 11. Low Noise, Wide VIN Range 5V Converter
3130f
For more information www.linear.com/LTC3130
31
LTC3130/LTC3130-1
APPLICATIONS INFORMATION
MBR0520
22nF
12V WALL ADAPTER INPUT
IOUT UP TO 600mA WHEN OPERATING FROM WALL ADAPTER
IOUT UP TO 500mA WHEN OPERATING FROM USB 3.0 INPUT
IOUT UP TO 300mA WHEN OPERATING FROM BATTERY
22nF
6.8µH
B130
USB 3.0 INPUT
BST1
PVIN
VIN
BSS314
RUN
GATE
VIN
10µF
LTC4412
Li-Ion
+
VCC
SW1
SW2
STAT
GND
1M
MPPC
PGOOD
PGOOD
VS1
1µF
CTL
VOUT
5V
22µF
EXTVCC
LTC3130-1
MODE
SENSE
BST2
VOUT
VCC
VS2
VCC
GND
PGND
4.7µF
3130 F12
Figure 12. Multiple VIN 5V Out Application, Using the LTC4412 PowerPath™ Controller
22nF
VMPPC = 8V
BST1
PVIN
VIN
VIN
+
10V
TO
14V
698k
10Ω
RUN
22nF
6.8µH
SW1
SW2
LTC3130-1
BST2
VOUT
10µF
VOUT
12V
100mA MIN
EXTVCC
MPPC
22µF
1µF
VCC
100k
MODE
PGOOD
VS1
VS2
VCC
GND
PGND
4.7µF
3130 F13
Figure 13. 12V Converter Uses MPPC Function to Maintain a Minimum VIN from a Current Limited Source
32
3130f
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
APPLICATIONS INFORMATION
22nF
DC SOURCE
<0.9V TO 25V
(2.4V + VD1
TO START)
D1*
BST1
PVIN
VIN
+
470µF
25V
×2
RUN
4.7µF
VCC
22nF
6.8µH
SW1
SW2
BST2
VOUT
47µF
VOUT
3.3V
EXTVCC
LTC3130-1
MPPC
MODE
PGOOD
VS1
VS2
VCC
GND
PGND
4.7µF
3130 F14
*D1 PREVENTS DISCHARGE OF INPUT CAPACITOR TO
THE SOURCE. MAY NOT BE REQUIRED IN ALL APPLICATIONS.
Figure 14. 3.3V Converter with "Last Gasp" Hold-Up, Runs Storage Capacitor Down to 0.9V
22nF
BAS70-05
UVLO THRESHOLDS
11.55V/0.95V
BST1
PVIN
VIN
22nF
6.8µH
SW1
SW2
BST2
VOUT
22µF
VOUT
5V
10M
INPUT SOURCES:
RF
AC
PIEZO
COIL-MAGNET
BAS70-06
47µF
16V
CER
×2
VCC
RUN
LTC3130-1
MODE
1M
1µF
EXTVCC
MPPC
PGOOD
VS1
VS2
GND
PGND
VCC
4.7µF
3130 F15
*D1 IS REQUIRED WHEN USING THE MSOP PACKAGE.
Figure 15. 5V Converter Operates in Hiccup-Fashion Off of Harvested Energy
Uses PGOOD to Provide Wide UVLO Hysteresis Range
Draws Only 2.5µA From VIN Prior to Start-Up
3130f
For more information www.linear.com/LTC3130
33
LTC3130/LTC3130-1
TYPICAL APPLICATIONS
22nF
VIN
4 Li-Ion
BST1
PVIN
VIN
UVLO = 11.41V
4.99M
SW1
10µF
VCC
SW2
BST2
VOUT
10µF
RUN
+
22nF
6.8µH
VOUT
12V
500mA
EXTVCC
LTC3130-1
MPPC
MODE
453k
PGOOD
VS1
VCC
GND
PGND
4.7µF
3130 F16
*D1 IS REQUIRED WHEN USING THE MSOP PACKAGE.
Figure 16. 12V Converter with Burst Mode Operation and VIN UVLO
10µH
SW
VIN
VOUT
LTC3525-3.3
SHDN
GND
2.2µF
VOUT1
3.3V
4.7µF
22nF
BST1
PVIN
VIN
VIN
RUN
10µF
ALKALINE
OR NiMH
0.85V to 1.5V
+
VCC
1µF
22nF
1.5µH
SW1
SW2
LTC3130
MPPC
BST2
VOUT
47µF
EXTVCC
100pF
402k
20k
PGOOD
ILIM
VOUT2
1.2V
FB
MODE
VCC
GND
PGND
4.7µF
2M
3130 F17
Figure 17. Single-Cell 1.2V, 200mA Buck Boost Converter,
Using the LTC3525-3.3 to Provide the EXTVCC Bias Supply
34
3130f
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
TYPICAL APPLICATIONS
1μF
22nF
BST1
PVIN
VIN
VIN
<0.9V TO 25V
(2.4V TO START)
VCC
1µF
SW2
BST2
VOUT
VOUT
1.80V
47µF
RUN
10µF
22nF
3.3µH
SW1
BAT54S
LTC3130-1
4.7µF
EXTVCC
MPPC
MODE
PGOOD
VS1
VS2
VCC
GND
PGND
4.7µF
3130 F18
Figure 18. Wide VIN Range, Low Noise 1.8V Converter Uses Charge Pump to Generate an EXTVCC Supply
22nF
BST1
PVIN
VIN
RUN
VIN
0.95V TO 25V
(2.4V TO START)
10µF
1µF
VCC
200mA 600mA
22nF
6.8µH
SW1
SW2
LTC3130
MPPC
BST2
VOUT
47µF
EXTVCC
15pF
2.61M
PGOOD
ILIM
VOUT
3.6V
100k
FB
MODE
VCC
GND
PGND
4.7µF
1M
3130 F19
Figure 19. Wide VIN Range 3.6V Converter with Two Programmed Current Limit Levels
3130f
For more information www.linear.com/LTC3130
35
LTC3130/LTC3130-1
PACKAGE DESCRIPTION
Please refer to http://www.linear.com/product/LTC3130#packaging for the most recent package drawings.
UDC Package
20-Lead Plastic QFN (3mm × 4mm)
(Reference LTC DWG # 05-08-1742 Rev Ø)
0.70 ±0.05
3.50 ±0.05
2.10 ±0.05
1.50 REF
2.65 ±0.05
1.65 ±0.05
PACKAGE OUTLINE
0.25 ±0.05
0.50 BSC
2.50 REF
3.10 ±0.05
4.50 ±0.05
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED
3.00 ±0.10
0.75 ±0.05
1.50 REF
19
R = 0.05 TYP
PIN 1 NOTCH
R = 0.20 OR 0.25
× 45° CHAMFER
20
0.40 ±0.10
1
PIN 1
TOP MARK
(NOTE 6)
4.00 ±0.10
2
2.65 ±0.10
2.50 REF
1.65 ±0.10
(UDC20) QFN 1106 REV Ø
0.200 REF
0.00 – 0.05
R = 0.115
TYP
0.25 ±0.05
0.50 BSC
BOTTOM VIEW—EXPOSED PAD
NOTE:
1. DRAWING IS NOT A JEDEC PACKAGE OUTLINE
2. DRAWING NOT TO SCALE
3. ALL DIMENSIONS ARE IN MILLIMETERS
4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE
MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE
5. EXPOSED PAD SHALL BE SOLDER PLATED
6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION
ON THE TOP AND BOTTOM OF PACKAGE
36
3130f
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
PACKAGE DESCRIPTION
Please refer to http://www.linear.com/product/LTC3130#packaging for the most recent package drawings.
MSE Package
16-Lead Plastic MSOP, Exposed Die Pad
(Reference LTC DWG # 05-08-1667 Rev F)
BOTTOM VIEW OF
EXPOSED PAD OPTION
2.845 ±0.102
(.112 ±.004)
5.10
(.201)
MIN
2.845 ±0.102
(.112 ±.004)
0.889 ±0.127
(.035 ±.005)
8
1
1.651 ±0.102
(.065 ±.004)
1.651 ±0.102 3.20 – 3.45
(.065 ±.004) (.126 – .136)
0.305 ±0.038
(.0120 ±.0015)
TYP
16
0.50
(.0197)
BSC
4.039 ±0.102
(.159 ±.004)
(NOTE 3)
RECOMMENDED SOLDER PAD LAYOUT
0.254
(.010)
0.35
REF
0.12 REF
DETAIL “B”
CORNER TAIL IS PART OF
DETAIL “B” THE LEADFRAME FEATURE.
FOR REFERENCE ONLY
9
NO MEASUREMENT PURPOSE
0.280 ±0.076
(.011 ±.003)
REF
16151413121110 9
DETAIL “A”
0° – 6° TYP
3.00 ±0.102
(.118 ±.004)
(NOTE 4)
4.90 ±0.152
(.193 ±.006)
GAUGE PLANE
0.53 ±0.152
(.021 ±.006)
DETAIL “A”
1.10
(.043)
MAX
0.18
(.007)
SEATING
PLANE
0.17 – 0.27
(.007 – .011)
TYP
1234567 8
0.50
(.0197)
BSC
NOTE:
1. DIMENSIONS IN MILLIMETER/(INCH)
2. DRAWING NOT TO SCALE
3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS.
MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS.
INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX
6. EXPOSED PAD DIMENSION DOES INCLUDE MOLD FLASH. MOLD FLASH ON E-PAD SHALL
NOT EXCEED 0.254mm (.010") PER SIDE.
0.86
(.034)
REF
0.1016 ±0.0508
(.004 ±.002)
MSOP (MSE16) 0213 REV F
3130f
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection
of its circuits
as described
herein will not infringe on existing patent rights.
For more
information
www.linear.com/LTC3130
37
LTC3130/LTC3130-1
TYPICAL APPLICATION
Wide VIN Range 5V Converter Uses Small Primary Battery to Guarantee Start-Up at VIN Less Than 1V
with Near Zero Steady-State Battery Current for Up to 10 Year Battery Life
22nF
BST1
PVIN
VIN
VIN
0.95V TO 25V
STOP RUN
1µF
VCC
22nF
6.8µH
SW1
SW2
BST2
VOUT
22µF
RUN
LTC3130-1
MPPC
PGOOD
VS1
VCC
BAT54C
EXTVCC
MODE
10µF
VOUT
5V
VS2
GND
PGND
+
4.7µF
VCC
3.6V
TADIRAN TL-4902
4.7µF
3130 TA02
RELATED PARTS
VIN
RANGE (V)
VOUT
RANGE (V)
IQ(μA)
PACKAGE
15V, 200mA, 1.2MHz, 95% Efficient Monolithic
Synchronous Buck/Boost
2.42V to 15V
1.4V to 15.75V
1.3µA
3mm × 3mm
QFN-16/MSOP-16E
LTC3115-1/LTC3115-2
40V, 2A, 2MHz, 95% Efficient Monolithic
Synchronous Buck/Boost
2.7V to 40V
2.7V to 40V
30µA
4mm × 5mm
DFN-16/TSSOP-20E
LTC3114-1
40V, 1A, 1.2MHz, 95% Efficient Monolithic
Synchronous Buck/Boost
2.2V to 40V
2.7V to 40V
30µA
3mm × 5mm
DFN-16/TSSOP-16E
LTC3112
15V, 2.5A, 750kHz, 95% Efficient Monolithic
Synchronous Buck/Boost
2.7V to 15V
2.7V to 14V
50µA
4mm × 5mm
DFN-16/TSSOP-20E
LTC3531
5.5V, 200mA, 600kHz Monolithic Synchronous
Buck/Boost
1.8V to 5.5V
2V to 5V
16µA
3mm × 3mm
DFN-8/ThinSOT
LTC3122
15V, 2.5A, 3MHz, 95% Efficient Monolithic
Synchronous Buck/Boost
1.8V to 5.5V
2.2V to 15V
25µA
3mm × 4mm
DFN-12/MSOP-12E
LTC3113
5V, 3A, 2MHz, 96% Efficient Monolithic Synch
Buck/Boost
1.8V to 5.5V
1.8V to 5.5V
40µA
4mm × 5mm
DFN-16/TSSOP-20E
LTC3118
Dual Input 18V, 2A, 1.2MHz, 95% Efficient
Monolithic Synchronous Buck/Boost with
PowerPath Control
2.2V to 18V
2.2V to 18V
50µA
4mm × 5mm
QFN-24/TSSOP-28E
LTC3111
1.5A (IOUT), 15V Synchronous Buck-Boost
DC/DC Converter
2.5V to 15V
2.5V to 15V
49µA
3mm × 4mm
DFN-14/MSOP-16
PART
DESCRIPTION
LTC3129/LTC3129-1
38 Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
For more information www.linear.com/LTC3130
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com/LTC3130
3130f
LT 0816 • PRINTED IN USA
 LINEAR TECHNOLOGY CORPORATION 2016
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