LTC3130 [Linear]
25V, 600mA Buck-Boost DC/DC Converter with 1.6μA Quiescent Current;
| 型号： | LTC3130 |
| 厂家： | 
Linear |
| 描述： | 25V, 600mA Buck-Boost DC/DC Converter with 1.6μA Quiescent Current |
| 文件： | 总38页 (文件大小：1906K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
LTC3130/LTC3130-1
25V, 600mA Buck-Boost
DC/DC Converter with
1.6µA Quiescent Current
FEATURES
DESCRIPTION
The LTC3130/LTC3130-1 are high efficiency, low noise,
600mA buck-boost converters with wide V and V
ranges. For high efficiency operation at light loads,
BurstModeoperationcanbeselected, reducingthequies-
cent current to just 1.6µA. Converter start-up is achieved
from sources as low as 7.5µW.
n
Regulates V
Above, Below or Equal to V
OUT
IN
n
Wide V Range: 2.4V to 25V,
IN
IN OUT
<1V to 25V (Using EXTV Input)
CC
n
n
n
n
V
Range: 1V to 25V
OUT
Adjustable Output Voltage (LTC®3130)
Four Selectable Fixed Output Voltages (LTC3130-1)
1.2µA No-Load Input Current in Burst Mode®
TheLTC3130/LTC3130-1employanultralownoise,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.
FeaturesincludeanaccurateRUNcomparator thresholdto
allow predictable regulator turn-on and a maximum power
point control (MPPC) capability that ensures maximum
power extraction from non-ideal sources such as photo-
voltaic panels. The LTC3130-1 includes an internal voltage
divider to provide four selectable fixed output voltages.
Operation (V = 12V, V
= 5V)
IN
OUT
n
n
n
n
n
n
n
n
n
n
600mA Output Current in Buck Mode
Pin-Selectable 850mA/450mA Current Limit (LTC3130)
Up to 95% Efficiency
Pin-Selectable Burst Mode Operation
1.2MHz Ultralow Noise PWM Frequency
Accurate RUN Pin Threshold
Power Good Indicator
Programmable Maximum Power Point Control
I = 500nA in Shutdown
Q
Thermally-Enhanced 20-Lead 3mm × 4mm QFN and
Additionalfeaturesincludeapowergoodoutput,anexternal
16-Lead MSOP Packages
V
input and thermal shutdown.
CC
APPLICATIONS
The LTC3130 and LTC3130-1 are available in thermally-
enhanced 20-lead 3mm × 4mm QFN and 16-lead MSOP
packages.
n
Long-Life, Battery-Operated Instruments
n
Portable Military Radios
n
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.
Low Power Sensors
n
Solar Panel Post-Regulator/Charger
TYPICAL APPLICATION
Efficiency vs Load
100
22nF
22nF
6.8µH
90
80
70
60
50
40
30
20
10
V
IN
4 Li-Ion
BST1 SW1
SW2 BST2
V
OUT
12V
PV
IN
V
OUT
600mA
10µF
V
10µF
IN
RUN
EXTV
CC
LTC3130-1
+
V
MPPC
MODE
CC
PGOOD
VS1
VS2
V
CC
V
IN
= 14.4V, V
= 12V
OUT
GND
PGND
0
4.7µF
0.01
0.1
1
10
100
800
LOAD (mA)
3130 TA01a
3130 TA01b
3130f
1
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
(Notes 1, 8)
ABSOLUTE MAXIMUM RATINGS
PV V , V
Voltage .............................–0.3 to 27.5V
Operating Junction Temperature
IN , IN OUT
EXTV Voltage .........................................–0.3 to 27.5V
Range (Notes 2, 5, 6)......................... –40°C to 125°C
Storage Temperature Range .................. –65°C to 150°C
Lead Temperature (Soldering, 10sec)
CC
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
MSE..................................................................300°C
PIN CONFIGURATION
TOP VIEW
20 19 18 17
TOP VIEW
BST1
1
2
3
4
5
6
16 BST2
15 SW2
1
2
3
4
5
6
7
8
GND
BST1
SW1
16 SW2
15 BST2
PV
V
IN
IN
14
V
OUT
V
14
13 PGOOD
12 EXTV
OUT
21
GND
17
GND
PV
V
13 PGOOD
IN
IN
RUN
12 EXTV
CC
RUN
11 MODE
V
CC
CC
V
10 VS1/ILIM
CC
MPPC
11 MODE
MPPC
9
VS2/FB
MSE PACKAGE
16-LEAD PLASTIC MSOP
7
8
9 10
T
= 125°C, θ = 40°C/W, θ = 10°C/W (NOTE 6)
JA JC
JMAX
EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB
UDC PACKAGE
20-LEAD (3mm × 4mm) PLASTIC QFN
T
= 125°C, θ = 52°C/W, θ = 6.8°C/W (NOTE 6)
JA JC
JMAX
EXPOSED PAD (PIN 21) IS GND, MUST BE SOLDERED TO PCB
http://www.linear.com/product/LTC3130#orderinfo
ORDER INFORMATION
LEAD FREE FINISH
LTC3130EUDC#PBF
LTC3130EUDC-1#PBF
LTC3130IUDC#PBF
LTC3130IUDC-1#PBF
LTC3130EMSE#PBF
LTC3130EMSE-1#PBF
LTC3130IMSE#PBF
LTC3130IMSE-1#PBF
TAPE AND REEL
PART MARKING*
LGTS
PACKAGE DESCRIPTION
20-Lead (3mm × 4mm) Plastic QFN
TEMPERATURE RANGE
–40°C to 125°C
LTC3130EUDC#TRPBF
LTC3130EUDC-1#TRPBF
LTC3130IUDC#TRPBF
LTC3130IUDC-1#TRPBF
LTC3130EMSE#TRPBF
LTC3130EMSE-1#TRPBF
LTC3130IMSE#TRPBF
LTC3130IMSE-1#TRPBF
LGTT
20-Lead (3mm × 4mm) Plastic QFN
20-Lead (3mm × 4mm) Plastic QFN
20-Lead (3mm × 4mm) Plastic QFN
16-Lead Plastic MSOP
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
LGTS
LGTT
3130
31301
3130
16-Lead Plastic MSOP
16-Lead Plastic MSOP
31301
16-Lead Plastic MSOP
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.
3130f
2
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
Start-Up Voltage
CONDITIONS
EXTV = 0V
MIN
TYP
MAX
UNITS
l
l
V
2.30
0.6
2.40
1.0
V
V
IN
CC
EXTV > 3.15V, RUN > 1.1V
CC
l
l
l
Input Voltage Range
EXTV > 3.15V, RUN > 1.1V
0.6
1.0
25
25
V
V
CC
Output Voltage Adjust Range (LTC3130)
Feedback Voltage (LTC3130)
For External FB Resistor Applications
From –40°C to +85°C (Note 3)
FB = 1.1V
0.975
0.980
1.000
1.000
0.1
1.020
1.020
10
V
V
Feedback Input Current (LTC3130)
nA
l
l
l
l
Fixed V
Voltages (LTC3130-1)
VS1 = VS2 = 0V
1.75
3.20
4.85
1.80
3.3
5.0
1.85
3.39
5.125
12.30
V
V
V
V
OUT
VS1 = V , VS2 = 0V
CC
VS1 = 0V, VS2 = V
CC
VS1 = VS2 = V
11.64
12.0
CC
V
V
V
Quiescent Current – Shutdown
Quiescent Current – UVLO
RUN < 0.2V
500
1.4
1.6
850
2.4
2.7
nA
µA
µA
IN
IN
IN
0.85V < RUN < 0.9V, EXTV = 0V
CC
Quiescent Current – Burst Mode Operation FB > 1.02V (LTC3130), V
> V
(LTC3130-1),
REG
OUT
(Sleeping)
MODE = 0V, RUN = V , MPPC > 1.05V
IN
NMOS Switch Leakage on V and V
SW1 = SW2 = 0V, V = V = 25V
OUT
5
100
nA
Ω
IN
OUT
IN
NMOS Switch On-Resistance
Inductor Average Current Limit
V
CC
= 4V
0.35
850
450
1.3
l
l
l
l
l
LTC3130-1 (Note 4), LTC3130: ILIM = V (Note 4)
660
250
0.9
0.6
91
1200
650
1.7
mA
mA
A
CC
LTC3130: ILIM = 0V (Note 4)
Inductor Peak Current Limit
LTC3130-1 (Note 4), LTC3130: ILIM = V (Note 4)
CC
LTC3130: ILIM = 0V (Note 4)
0.85
94
1.15
97
A
Maximum Boost Duty Cycle
LTC3130-1: V
< V
(Note 7),
REG
%
OUT
(Percentage of Period SW2 is Low)
LTC3130: FB < 0.975V (Note 7)
l
l
Minimum Duty Cycle
LTC3130-1: V > V (Note 7),
LTC3130: FB > 1.02V (Note 7)
0
%
OUT
REG
Switching Frequency
1.00
0.95
1.20
70
1.40
MHz
ns
V
SW1 and SW2 Minimum Low Time
MPPC Reference Voltage
MPPC Input Current
(Note 3)
l
1.00
1
1.05
20
MPPC = 5V
nA
V
l
l
l
RUN Logic Threshold to Enable Reference
RUN Threshold to Enable Switching (Rising)
RUN Threshold Hysteresis
0.2
1.01
90
0.6
1.05
100
0.85
1.09
110
V
IN
> 2.4V or EXTV > 3.15V
V
CC
mV
RUN Input Current
RUN = 25V
RUN = 1V
1
0.1
30
5
nA
nA
l
l
ILIM Input Logic High
ILIM Input Logic Low
ILIM Input Current
(LTC3130)
1.1
1.1
1.1
V
V
(LTC3130)
0.35
20
(LTC3130) ILIM = 5V
(LTC3130-1)
1
1
nA
V
l
l
VS1, VS2 Input Logic High
VS1, VS2 Input Logic Low
VS1, VS2 Input Current
MODE Input Logic High
MODE Input Logic Low
MODE Input Current
(LTC3130-1)
0.35
20
V
(LTC3130-1) VS1, VS2 = 5V
nA
V
l
l
0.35
V
MODE = 5V (If RUN is Low or V is in UVLO)
MODE = 5V (If Switching is Enabled)
1
1.7
20
4
nA
µA
CC
3130f
3
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
CONDITIONS
MIN
TYP
12
MAX
UNITS
ms
V
Soft-Start Time
For Average Inductor Current to Reach Limit
V
CC
V
CC
V
CC
V
CC
V
CC
V
CC
Voltage
(EXTV or V ) > 4.7V, RUN > 0.85V
4
CC
IN
Voltage -– Shutdown
RUN ≤ 0.2V
3.25
50
V
Dropout Voltage (V – V
)
CC
V
V
= 3.0V, Switching
= 0V
100
34
mV
mA
V
IN
IN
Current Limit
17
CC
l
l
l
UVLO Threshold (Rising)
UVLO Hysteresis
2.20
100
2.3
120
3.0
260
2.40
135
3.15
mV
V
EXTV Enable Threshold
2.85
CC
EXTV Enable Hysteresis
mV
V
CC
EXTV Input Operating Range
3.15
25
CC
EXTV Quiescent Current – Burst Mode
Operation (Sleeping)
EXTV > 3.15V, FB >1.02V(LTC3130), MPPC > 1.05V
1.6
2.5
µA
CC
CC
V
> V (LTC3130-1), MODE = 0V, RUN > 1.10V
OUT REG
EXTV Quiescent Current – Shutdown
EXTV = 5V, RUN < 0.2V
400
32
750
68
nA
mA
nA
CC
CC
EXTV Current Limit
V
= 0V, EXTV = 15V
CC CC
CC
V
IN
Sleep Current When Powered by EXTV
FB > 1.02V (LTC3130), V
> V (LTC3130-1),
REG
600
CC
OUT
EXTV > 3.15V, MODE = 0V,
CC
RUN >1.10V, V = 12V, MPPC > 1.05V
IN
l
V
V
V
UV Threshold
Rising
0.35
–7.0
0.7
55
0.95
V
mV
µA
OUT
OUT
OUT
UV Hysteresis
Quiescent Current – Shutdown
(V –1)
OUT
(V
OUT
)
)
27
17
V
OUT
Quiescent Current – Burst Mode
MODE = 0V, FB > 1.02V, MPPC > 1.05V
(V –1)
OUT
(V
OUT
µA
Operation (Sleeping)
27
–5.0
2.5
165
1
17
PGOOD Threshold, Rising
PGOOD Hysteresis
PGOOD Voltage Low
PGOOD Leakage
Referenced to Programmed V
Referenced to Programmed V
Voltage
Voltage
–3.0
%
%
OUT
OUT
I
= 1mA
250
50
mV
nA
SINK
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 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 2: The LTC3130/LTC3130-1 is tested under pulsed load conditions
such that T ≈ T . The LTC3130E/LTC3130E-1 is guaranteed to meet
J
A
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 (T ) is
J
Note 7: Switching time measurements are made in an open-loop test
calculated from the ambient temperature (T ) and power dissipation (P )
A
D
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.
according to the formula:
T = T + (P • θ °C/W),
J
A
D
JA
where θ is the package thermal impedance. Note that the maximum
JA
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.
3130f
4
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted.
Efficiency, VOUT = 1.8V,
PWM Mode
Efficiency, VOUT = 3.3V,
PWM Mode
Efficiency, VOUT = 5V,
PWM Mode
100
90
80
70
60
50
40
30
20
10
0
100
90
80
70
60
50
40
30
20
10
0
100
90
80
70
60
50
40
30
20
10
0
V
V
V
V
V
= 2.5V
= 3.6V
= 5V
= 12V
= 24V
V
V
V
V
V
= 2.5V
= 3.6V
= 5V
= 12V
= 24V
V
V
V
V
V
= 2.5V
= 3.6V
= 5V
= 12V
= 24V
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
0.01
0.1
1
10
100
1k
0.01
0.1
1
10
100
1k
0.01
0.1
1
10
100
1k
LOAD CURRENT (mA)
LOAD CURRENT (mA)
LOAD CURRENT (mA)
3130 G01
3130 G03
3130 G02
Efficiency, VOUT = 12V,
PWM Mode
Efficiency, VOUT = 1.8V, Burst
Mode Operation (LTC3130-1)
Power Loss, VOUT = 1.8V, Burst
Mode Operation (LTC3130-1)
1k
100
10
100
90
80
70
60
50
40
30
20
10
0
100
90
80
70
60
50
40
30
20
10
0
V
V
V
V
V
= 2.5V
= 3.6V
= 5V
= 12V
= 24V
IN
IN
IN
IN
IN
1
0.1
V
V
V
V
V
= 2.5V
= 3.6V
= 5V
= 12V
= 24V
V
V
V
V
V
= 2.5V
= 3.6V
= 5V
= 12V
= 24V
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
0.01
0.001
0.01
0.1
1
10
100
1k
0.01
0.1
1
10
100
1k
0.01
0.1
1
10
100
1k
LOAD CURRENT (mA)
LOAD CURRENT (mA)
LOAD CURRENT (mA)
3130 G06
3130 G04
3130 G05
Efficiency, VOUT = 3.3V, Burst
Mode Operation (LTC3130-1)
Power Loss, VOUT = 3.3V, Burst
Mode Operation (LTC3130-1)
Efficiency, VOUT = 5V, Burst Mode
Operation (LTC3130-1)
100
90
80
70
60
50
40
30
20
10
0
1k
100
10
100
90
80
70
60
50
40
30
20
10
0
1
0.1
V
V
V
V
V
= 2.5V
V
V
V
V
V
= 2.5V
= 3.6V
= 5V
= 12V
= 24V
V
V
V
V
V
= 2.5V
= 3.6V
= 5V
= 12V
= 24V
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
= 3.6V
= 5V
= 12V
= 24V
0.01
0.001
0.01
0.1
1
10
100
1k
0.01
0.1
1
10
100
1k
0.01
0.1
1
10
100
1k
LOAD CURRENT (mA)
LOAD CURRENT (mA)
LOAD CURRENT (mA)
3130 G07
3130 G08
3130 G09
3130f
5
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted.
Power Loss, VOUT = 5V, Burst
Mode Operation (LTC3130-1)
Efficiency, VOUT = 12V, Burst
Mode Operation (LTC3130-1)
Power Loss, VOUT = 12V, Burst
Mode Operation (LTC3130-1)
100
90
80
70
60
50
40
30
20
10
0
1k
100
10
1k
100
10
1
1
0.1
V
V
V
V
V
= 2.5V
= 3.6V
= 5V
= 12V
= 24V
V
V
V
V
V
= 2.5V
= 3.6V
= 5V
= 12V
= 24V
V
V
V
V
V
= 2.5V
= 3.6V
= 5V
= 12V
= 24V
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
0.1
0.01
0.01
0.001
0.01
0.1
1
10
100
1k
0.01
0.1
1
10
100
1k
0.01
0.1
1
10
100
1k
LOAD CURRENT (mA)
LOAD CURRENT (mA)
LOAD CURRENT (mA)
3130 G11
3130 G12
3130 G10
Efficiency, VOUT = 8V,
PWM Mode (LTC3130)
Efficiency, VOUT = 8V, Burst Mode
Operation (LTC3130)
Power Loss , VOUT = 8V, Burst
Mode Operation (LTC3130)
100
90
80
70
60
50
40
30
20
10
0
1k
100
10
100
90
80
70
60
50
40
30
20
10
0
V
V
V
V
V
= 2.5V
= 3.6V
= 5V
= 12V
= 24V
IN
IN
IN
IN
IN
1
V
V
V
V
V
= 2.5V
= 3.6V
= 5V
= 12V
= 24V
IN
IN
IN
IN
IN
V
V
V
V
V
= 2.5V
= 3.6V
= 5V
= 12V
= 24V
IN
IN
IN
IN
IN
0.1
0.01
0.01
0.1
1
10
100
1k
0.01
0.1
1
10
100
1k
0.01
0.1
1
10
100
1k
LOAD CURRENT (mA)
LOAD CURRENT (mA)
LOAD CURRENT (mA)
3130 G13
3130 G15
3130 G14
Efficiency, VOUT = 15V
(LTC3130)
Power Loss, VOUT = 15V, Burst
Mode Operation (LTC3130)
Efficiency, VOUT = 24V
(LTC3130)
100
90
80
70
60
50
40
30
20
10
0
100
90
80
70
60
50
40
30
20
10
0
1k
100
10
1
V
V
V
V
= 3.6V
IN
IN
IN
IN
= 5V
= 12V
= 24V
0.1
0.01
0.1
1
10
LOAD CURRENT (mA)
Burst Mode OPERATION: PWM:
100
1k
0.01
0.1
1
10
100
1k
0.01
0.1
1
10
LOAD CURRENT (mA)
Burst Mode OPERATION: PWM:
100
1k
LOAD CURRENT (mA)
3130 G17
3130 G16
3130 G18
V
V
V
V
= 3.6V
V
V
V
V
= 3.6V
= 5V
= 12V
= 24V
IN
IN
IN
IN
V
= 5V
IN
IN
IN
IN
V
V
V
= 5V
= 12V
= 24V
IN
IN
IN
IN
= 5V
V
= 12V
= 12V
= 24V
V
= 24V
3130f
6
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted.
VIN Shutdown Current vs
VIN (RUN = 0V, EXTVCC = 0V)
Power Loss, VOUT = 24V, Burst Mode
Operation (LTC3130)
Maximum Output Current
vs VIN and VOUT
700
600
500
400
300
200
100
0
1.00
0.90
0.80
0.70
0.60
0.50
0.40
0.30
0.20
0.10
0
1k
100
10
V
V
V
V
V
= 1.8V
= 3.3V
= 5V
= 12V
= 25V
OUT
OUT
OUT
OUT
OUT
1
V
V
V
= 5V
= 12V
= 24V
IN
IN
IN
0.1
0
5
10
V
15
(V)
20
25
0
5
10
15
20
25
0.01
0.1
1
10
100
1k
V
(V)
LOAD CURRENT (mA)
IN
IN
3130 G20
3130 G21
3130 G19
No-Load Input Current in Burst
Mode Operation vs VIN and VOUT
(LTC3130-1, MODE = 0V)
V
IN UVLO Current
No-Load Input Current in Burst
Mode Operation vs VIN and VOUT
(LTC3130, MODE = 0V)
vs VIN (0.85V ≤ RUN ≤ 1.01V,
EXTVCC = 0V)
1.80
1.60
1.40
1.20
1.00
0.80
0.60
0.40
0.20
0
30
25
20
15
10
5
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
I
= 2μA (FB DIVIDER)
V
V
V
V
= 1.8V
= 3.3V
= 5V
OUT
OUT
OUT
OUT
OUT
V
OUT
V
OUT
V
OUT
V
OUT
V
OUT
= 1.8V
= 3.3V
= 5V
= 12V
= 25V
=1 2V
0
0
5
10
V
15
(V)
20
25
0
5
10
15
(V)
20
25
0
5
10
V
15
(V)
20
25
V
IN
IN
IN
3130 G22
3130 G23
3130 G24
No-Load Input Current in Fixed
Frequency vs VIN and VOUT
Burst Mode Operation, Load
Current Threshold vs VIN and
VOUT (MODE = 0V)
Average Inductor Current Limit
vs MPPC Voltage
(MODE = VCC
)
0.15
0.12
0.09
0.06
0.03
0
0.80
0.70
0.60
0.50
0.40
0.30
0.20
0.10
0
30
25
20
15
10
5
V
V
V
V
V
= 1.8V
= 3.3V
= 5V
= 12V
= 25V
OUT
OUT
OUT
OUT
OUT
V
V
V
V
V
= 1.8V
= 3.3V
= 5V
= 12V
= 25V
OUT
OUT
OUT
OUT
OUT
0
0
5
10
V
15
(V)
20
25
0.95
0.98
1.01
MPPC (V)
1.04
1.07
1.10
0
5
10
V
15
(V)
20
25
IN
IN
3130 G26
3130 G27
3130 G25
3130f
7
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted.
Average Current Limit vs
Temperature (Normalized to 25°C)
FB Voltage vs Temperature
LTC3130 (Normalized to 25°C)
Output Voltage vs Temperature
LTC3130–1 (Normalized to 25°C)
0.00
–0.10
–0.20
–0.30
–0.40
–0.50
–0.60
–0.70
–0.80
–0.90
–1.00
0
–1.00
–2.00
–3.00
–4.00
–5.00
–6.00
–7.00
–8.00
–9.00
–10.00
0.00
–0.10
–0.20
–0.30
–0.40
–0.50
–0.60
–0.70
–0.80
–0.90
–1.00
–50 –25
0
25 50 75 100 125 150
–50 –25
0
25 50 75 100 125 150
–50 –25
0
25 50 75 100 125 150
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
3130 G29
3130 G28
3130 G30
Oscillator Frequency vs
Temperature (Normalized to 25°C)
Oscillator Frequency vs VCC
(Normalized to VCC = 4V)
Accurate RUN Threshold vs
Temperature (Normalized to 25°C)
100
99
0
–1.00
–2.00
–3.00
–4.00
–5.00
–6.00
–7.00
–8.00
–9.00
–10.00
0.00
–0.10
–0.20
–0.30
–0.40
–0.50
–0.60
–0.70
–0.80
–0.90
–1.00
98
97
2.4
2.8
3.2
(V)
3.6
4.0
–50 –25
0
25 50 75 100 125 150
–50 –25
0
25 50 75 100 125 150
V
°
TEMPERATURE (°C)
CC
TEMPERATURE ( C)
3130 G32
3130 G31
3130 G33
Fixed Frequency PWM
Waveforms (Buck Region)
Switch RDS(ON) vs Temperature
Switch RDS(ON) vs VCC
0.55
0.50
0.45
0.40
0.35
0.30
0.25
0.20
0.45
0.42
0.39
0.36
0.33
0.30
SW2
(5V/DIV)
SW1
(10V/DIV)
INDUCTOR
CURRENT
(0.5A/DIV)
3130 G36
200nsec/DIV
–50 –25
0
25 50 75 100 125 150
2.5
3
3.5
4
TEMPERATURE (°C)
V
(V)
CC
3131 G34
3134 G35
3130f
8
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted.
Fixed Frequency PWM
Waveforms (Buck-Boost Region)
Fixed Frequency PWM
Waveforms (Boost Region)
Fixed Frequency Output
Voltage Ripple
SW2
(10V/DIV)
SW2
(5V/DIV)
V
OUT
(50mV/DIV)
SW1
(5V/DIV)
SW1
(5V/DIV)
INDUCTOR
CURRENT
(0.2A/DIV)
INDUCTOR
CURRENT
(0.5A/DIV)
INDUCTOR
CURRENT
(0.5A/DIV)
0
3130 G37
3130 G39
3130 G38
200nsec/DIV
500nsec/DIV
200nsec/DIV
12V , 5V
LOAD
,
OUT
IN
I
= 0.5A, C
= 22µF
OUT
PWM to Burst Mode Operation
Transition
Start-Up Sequence When
Applying VIN (RUN Tied to VIN)
Burst Mode Operation Waveforms
V
IN
V
OUT
(10V/DIV)
V
OUT
(100mV/
DIV)
(50mV/DIV)
V
CC
(2V/DIV)
MODE PIN
(2V/DIV)
V
OUT
(2V/DIV)
INDUCTOR
CURRENT
(0.2A/DIV)
INDUCTOR
CURRENT
(0.2A/DIV)
INDUCTOR
CURRENT
(0.2A/DIV)
3130 G42
3130 G41
3130 G40
2msec/DIV
1msec/DIV
= 20mA, C = 22µF
OUT
20μsec/DIV
C
= 22µF
12V , 5V
LOAD
,
OUT
5V
OUT
IN
OUT
I
I
=10mA
= 22µF
LOAD
C
OUT
Start-Up Sequence When Raising
RUN Pin (VIN = 12V)
VCC Response to a Step on
EXTVCC (VIN = 3V)
V
CC Response to a Step on
EXTVCC (VIN > 4V)
RUN
(5V/DIV)
V
CC
(2V/DIV)
V
CC
V
CC
(2V/DIV)
(2V/DIV)
0
0
V
OUT
(2V/DIV)
EXTV
(5V/DIV)
0
CC
EXTV
(5V/DIV)
0
INDUCTOR
CURRENT
(0.2A/DIV)
CC
3138 G43
3130 G44
3130 G45
2msec/DIV
1msec/DIV
1msec/DIV
3130f
9
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted.
Step Load Transient Response in
Fixed Frequency
Step Load Transient Response in
Burst Mode Operation
PGOOD Response to a Drop in
V
OUT Due to a Step Overload
V
OUT
(2V/DIV)
PGOOD
(2V/DIV)
VOUT
(100mV/DIV)
V
OUT
(100mV/DIV)
INDUCTOR
CURRENT
(0.2A/DIV)
INDUCTOR
CURRENT
(0.5A/DIV)
INDUCTOR
CURRENT
(0.5A/DIV)
3130 G48
3130 G46
3130 G47
500μsec/DIV
500μsec/DIV
1msec/DIV
12V , 5V
,
OUT
12V , 5V
,
OUT
IN
IN
50mA to 500mA LOAD STEP
= 22µF, L = 10μH
10mA to 250mA LOAD STEP
= 22µF, L = 10μH
C
OUT
C
OUT
MPPC Response to an Overload
(VMPPC Set to 5V at VIN)
V
IN Line Step Response in
Fixed Frequency
V
OUT
V
(5V/DIV)
OUT
(1V/DIV)
V
IN
(5V/DIV)
V
IN
(10V/DIV)
INDUCTOR
CURRENT
(0.2A/DIV)
INDUCTOR
CURRENT
(0.2A/DIV)
3130 G50
50μsec/DIV
5V TO 25V V STEP,
OUT
LIGHT LOAD
5V
,
3130 G49
OUT
2msec/DIV
IN
V
V
= 9V
OC
C
= 22µF, L = 10μH,
= 12V
= 20Ω
= 33μF
OUT
R
IN
IN
C
Output Voltage Short-Circuit
Waveforms
V
IN Line Step Response in
Burst Mode Operation
V
OUT
V
OUT
(2V/DIV)
(1V/DIV)
V
IN
INDUCTOR
CURRENT
(0.2A/DIV)
(10V/DIV)
INDUCTOR
CURRENT
(0.2A/DIV)
3130 G51
50μsec/DIV
3130 G52
5V
,
OUT
10μsec/DIV
5V TO 25V V STEP,
IN
C
= 22µF, L = 10μH,
OUT
LIGHT LOAD
3130f
10
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
(QFN/MSOP)
PIN FUNCTIONS
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.
divider voltage drops below 1.0V (typical), the inductor
current will be reduced to servo V to the programmed
IN
minimum voltage, as set by the divider. Note that this pin
isverynoisesensitive,thereforeminimizetracelengthand
stray capacitance. Refer to the Applications Information
section of this data sheet for more detail on programming
PV (Pin 2/Pin 4): Power Input for the Buck-Boost
IN
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.
the MPPC. If this function is not needed, tie the pin to V .
CC
GND (Pins 7-8, Exposed Pad Pin 21/Pin 1, Exposed Pad
Pin 17): Ground. Provide a short direct PCB path between
GNDandthegroundplanethattheexposedpadissoldered
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.
V
(Pin 3/Pin 5): Input Voltage for the V Regulator.
CC
IN
Connect a minimum of 1µF ceramic decoupling capacitor
from this pin to the ground plane.
FB (Pin 9/Pin 9 (LTC3130)): Feedback input to the error
RUN (Pin 4/Pin 6): Input to the Run Comparator. Rais-
ing 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
amplifier.ConnecttoaresistordividerfromV toground.
OUT
The output voltage can be adjusted from 1.0V to 25V by:
R1
R2
V
OUT =1.00V • 1+
(Refer to Figure 2)
resistor divider from V to ground allows programming
IN
an accurate V start threshold. To enable the converter
Notethatthispinisverynoisesensitive,thereforeminimize
trace length and stray capacitance. Please refer to the
ApplicationsInformationsectionofthisdatasheetformore
detail on setting the FB voltage divider, and the optional
use of an optional feed-forward capacitor.
IN
all the time, tie RUN to V . See the Operation section of
IN
this data sheet for more guidance.
V
(Pin 5/Pin 7): Output Voltage of the Internal 4V
CC
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
V or EXTV . Note that V should not be back-driven.
VS2(Pin9/Pin9(LTC3130-1)):OutputVoltageSelectPin.
Connect this pin to ground or V to program the output
CC
voltage(seeTable1).Thispincanalsobedynamicallydriven
IN
CC
CC
by any logic signal that satisfies the specified thresholds.
V
can be used to power external circuitry as long as
CC
the peak load current doesn’t exceed 2mA. Note that this
ILIM (Pin 10/Pin 10 (LTC3130)): Programming pin to
selectbetween250mAor660mAaverageminimuminduc-
tor current limit. Please see the Maximum Output Current
curve in the Typical Performance Characteristics section.
added load will increase the minimum required operating
V voltage by up to 60mV.
IN
NC (Pin 17, QFN Only): Unused. This pin should be
grounded.
ILIM=Low (ground):Setsthe average inductorcurrent
limit to 250mA (minimum) for low current applications
MPPC (Pin 6/Pin 8): Maximum Power Point Control
Programming Input. Connect this pin to a resistor divider
ILIM = High (tie to V ): Sets the average inductor
CC
from V to ground to enable MPPC functionality. If the
current limit to 660mA (minimum)
IN
This pin can also be dynamically driven by any logic signal
that satisfies the specified thresholds.
3130f
11
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
PIN FUNCTIONS (QFN/MSOP)
VS1 (Pin 10/Pin 10 (LTC3130-1)): Output Voltage Select
PGOOD (Pin 13/Pin 13): Open-drain output that pulls to
ground when FB (LTC3130) or V (LTC3130-1) drops
Pin. Connect this pin to ground or V to program the
CC
OUT
output voltage (see Table 1). This pin can also be dynami-
cally driven by any logic signal that satisfies the specified
thresholds.
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 V or EXTV , this pin will
IN
CC
be forced low in shutdown or UVLO.
Table 1. VOUT Program Settings for the LTC3130-1
VS2
0
VS1
V
V
(Pin 14/Pin 14): Output Voltage of the Converter.
OUT
OUT
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.
0
1.8V
3.3V
5.0V
12V
0
V
CC
V
V
0
CC
CC
V
CC
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.
MODE (Pin 11/Pin 11): Mode Select Pin.
MODE = Low (ground): Enables automatic Burst Mode
operation
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.
MODE = High (tie to V ): Fixed frequency PWM
operation
CC
PGND(Pins18-19)/(Pin1):PowerGround.Provideashort
direct PCB path between PGND and the ground plane.
This pin can also be dynamically driven by any logic signal
that satisfies the specified thresholds. There is an internal
3MΩpull-downresistorconnectedtoMODEonceswitch-
ing is enabled, to prevent it from floating.
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.
EXTV (Pin 12/Pin 12): Second Input to the Internal
CC
V
Regulator. This pin can be tied to V
or another
CC
OUT
voltage between 3V and 25V. If this input is used, it will
power the IC, reducing the quiescent current draw on
V
in buck applications and allowing the converter to
IN
operate from a V voltage down to 1V or less. A 4.7µF
IN
decoupling capacitor is recommended on this pin unless
it is tied directly to the V
used, this pin should be grounded.
decoupling capacitor. If not
OUT
3130f
12
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
LTC3130 BLOCK DIAGRAM
PV
EXTV
LDO
BST
SW1
SW2
BST2
IN
CC
V
V
OUT
IN
V
V
IN
OUT
V
V
CC
CC
VCC_GD
DRIVER
A
B
D
C
DRIVER
DRIVER
V
REF
I
V
CC
SENSE
4V
DRIVER
V
1.0V
SENSE
V
VREF_GD
REF
START
RUN
+
–
–
+
0.6V
FB
V
V
+
–
SENSE
1.2A
I
UV
PK
LOGIC
0.7V
+
–
ON
V
C
SENSE
ENABLE
1.05V
+
–
SENSE
I
–
+
ZERO
–
+
THERMAL
SHUTDOWN
50mA
+
–
V
1.0V
SOFT-START
RESET
MPPC
OSC
+
1.0V
–
PGOOD
–
+
MODE
–
+
600mA
200mA
–
+
3M
SLEEP
–7.5%
CLAMP
100mV
VCC_GD
GND
PGND
I
LIM
3130 BD
V
CC
3130f
13
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
LTC3130-1 BLOCK DIAGRAM
PV
EXTV
LDO
BST
SW1
SW2
BST2
IN
CC
V
V
OUT
IN
V
V
IN
OUT
V
CC
V
CC
VCC_GD
VS1
VS2
DRIVER
A
B
D
C
DRIVER
1.0V
V
OUT
I
V
CC
SELECT
INPUTS
SENSE
4V
DRIVER
DRIVER
V
1.0V
SENSE
V
VREF_GD
REF
START
RUN
0.6V
+
–
–
+
V
+
–
SENSE
I
UV
PK
LOGIC
1.2A
0.7V
+
–
ON
V
C
SENSE
ENABLE
1.05V
V
+
–
SENSE
I
–
+
ZERO
–
+
FB
THERMAL
SHUTDOWN
50mA
+
–
PWM
V
1.0V
SOFT-START
RESET
MPPC
OSC
+
1.0V
–
PGOOD
–
+
MODE
–
+
–
+
600mA
3M
SLEEP
–7.5%
CLAMP
100mV
VCC_GD
GND
PGND
31301 BD
3130f
14
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
OPERATION
INTRODUCTION
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 user-
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
programmed V voltage thresholds. With a wide voltage
IN
range, 1.6µA Burst Mode current and programmable
RUN and MPPC pins, these highly integrated monolithic
converters are well suited for many diverse applications.
load. The LTC3130 has a FB pin for programming V
OUT
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,
PWM MODE OPERATION
low R
N-channel power switches reduce solution
DS(ON)
If the MODE pin is high (or if the load current on the con-
verter is high enough to command PWM mode operation
with MODE low), the LTC3130/LTC3130-1 operate in a
fixed1.2MHzPWM modeusinganinternallycompensated
averagecurrentmodecontrolloop.PWM modeminimizes
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
loweroutputvoltagerippleincomparisontothetraditional
buck-boost converter.
complexity and maximize efficiency. A proprietary switch
control algorithm allows the buck-boost converter to
maintainoutputvoltageregulationwithinputvoltagesthat
are above, below or equal to the output voltage. Transi-
tions 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.
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.
C
BST1
C
BST2
L
BST1
PV
A
SW1
SW2
D
V
OUT
BST2
IN
V
CC
V
CC
A MPPC (maximum power point control) function is also
provided that prevents the converter from pulling enough
V
V
CC
CC
current to drop V below a user-programmed threshold
IN
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.
B
C
PGND
PGND
LTC3130
3130 F01
Figure 1. Power Stage Schematic
3130f
15
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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
fortheminimumswitchlowduration(typically70ns).Dur-
ing the switch low duration, switch C is turned on which
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 cur-
rentcommandasnecessarytomaintainV inregulation.
OUT
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.
forces SW2 low and charges the flying capacitor, C
.
BST2
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.
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.
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, C
. This ensures
BST1
that the switch A gate driver power supply rail on BST1 is
maintained.ThedutycycleofswitchesCandDareadjusted
to maintain output voltage regulation in boost mode.
Thecompensationcomponentsrequiredtoensureproper
operation have been carefully selected and are integrated
within the LTC3130/LTC3130-1.
Oscillator
TheLTC3130/LTC3130-1operatefromaninternaloscilla-
tor with a nominal fixed frequency of 1.2MHz. This allows
the DC/DC converter efficiency to be maximized while still
using small external components.
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.
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.
Thevoltageerroramplifieroutput(V )isinternallyclamped
C
toanaccuratethreshold.Sincetheaverageinductorcurrent
is proportional to V , the clamp level sets the maximum
C
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 cur-
rent 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
Referring to the Block Diagrams, a high gain, internally
compensated transconductance voltage error amplifier
monitors V
through a voltage divider connected to the
OUT
FB pin (LTC3130) or via the internal V
voltage divider
OUT
to 90% of the inductor current I (due to the forced low
L
(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,
time of the B and C switches, where no current is delivered
to the output):
I
≈ 0.9 • I
L
OUT(BUCK)
3130f
16
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LTC3130/LTC3130-1
OPERATION
In boost mode, the output current is related to average
inductor current and duty cycle by:
The output voltage can be set anywhere from 1.0V to 25V.
Anoptionalfeed-forwardcapacitorcanbeaddedinparallel
withR1(asshowninFigure2)toreduceBurstModeripple
and improve transient response of the voltage loop. The
typical feed-forward capacitor value can be calculated by:
V
VOUT
IN
IOUT(BOOST) ≈ IL •
• η
Since the output current in boost mode is reduced by the
40
R1(Meg)
CFF pF =
( )
step-upratioofV /V , theoutputcurrentratinginbuck
IN OUT
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
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 fre-
quency gain. The value isn’t critical, and resistor values of
efficiency (η) in boost mode will generally be lower due
2
to higher I • R
losses in the power switches. This
L
DS(ON)
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.
V
OUT
C
FF
OPTIONAL
FEED-FORWARD
C
OUT
R1
R2
LTC3130
R
FF
FB
GND
3130 F02
The LTC3130/LTC3130-1 measure and control average
inductor current, and therefore, the inductor ripple cur-
rent 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
Figure 2. VOUT Feedback Divider (Showing Optional
Feed-Forward Capacitor)
approximately R1/20 are generally recommended.
V
Programming Pins (LTC3130-1)
OUT
The LTC3130-1 has a precision internal voltage divider
on V , eliminating the need for high value external
related to the boost ratio. For example, for a 5V V to 15V
IN
OUT
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.
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 V
regulation er-
OUT
Programming V
(LTC3130)
OUT
rors. 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 output voltage of the LTC3130 is programmed using
an external resistor divider from V to ground with the
OUT
divider tap connected to the FB pin, as shown in Figure 2,
according to the equation:
The VS1 and VS2 pins can be grounded or connected
to V 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.
CC
R1
R2
V
OUT =1.00V • 1+
(Refer to Figure 2)
3130f
17
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LTC3130/LTC3130-1
OPERATION
Note that driving VS1 or VS2 to a logic high that is below
level of this magnitude may occur during a fault, such as
an output short circuit, or possibly for a few cycles dur-
ing 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.
the V voltage can result in an increase of up to 1µA of
CC
current draw from V per VS pin. This does not occur in
CC
shutdown or if V is below its UVLO threshold, in which
CC
case these inputs are disabled and will not cause any extra
current draw.
Note that if a peak current limit is reached while V
is
OUT
also less than 0.7V typical (which would be indicative of
a shorted output), a soft-start cycle will be triggered.
Table 1. VOUT Program Settings for the LTC3130-1
VS2
0
VS1
V
OUT
0
1.8V
3.3V
5.0V
12V
I
Comparator
ZERO
0
V
CC
V
0
The LTC3130/LTC3130-1 feature near discontinuous
inductor current operation at light output loads by virtue
CC
V
V
CC
CC
of the I
comparator circuit. By limiting the reverse
ZERO
Programming the ILIM Threshold (LTC3130 only)
current magnitude in PWM mode, a balance between low
noise operation and improved efficiency at light loads is
The LTC3130 has two average current limit settings,
which are set by the ILIM pin. If ILIM is pulled high (tied
achieved. The I
threshold is set near the zero current
ZERO
level in PWM mode, and as a result the reverse current
magnitude will be a function of inductance value and out-
put voltage due to the comparator’s propagation delay. In
general, higher output voltages and lower inductor values
will result in increased peak reverse current.
to V ), the average inductor current limit will be set to
CC
660mA (minimum). If the ILIM pin is pulled low (tied to
ground), theaverageinductorcurrentlimitwillbereduced
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.
In automatic Burst Mode operation (MODE pin low), the
I
threshold is increased so that reverse inductor cur-
ZERO
rent does not normally occur. This maximizes efficiency
at light loads.
V
OUT
Undervoltage and Foldback Current Limit
Note that reverse current is also inhibited during soft-
The LTC3130/LTC3130-1 include a foldback current limit
feature to reduce power dissipation into a shorted output.
start (regardless of the MODE pin setting) to prevent V
discharge when starting up into pre-biased outputs.
OUT
When V
is less than 0.7V (typical), the average current
OUT
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.
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
normalcontinuousPWM switchingaboveapredetermined
minimum output load and will automatically transition to
power saving Burst Mode operation below this output
load level. Refer to the Typical Performance Character-
istics section of this data sheet to determine the Burst
Mode transition threshold for various combinations of
Overload Peak Current Limit
The LTC3130/LTC3130-1 also have peak overload current
(I ) and zero current (I
PEAK
) comparators. The I
ZERO PEAK
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
V and V
.
IN
OUT
3130f
18
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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
thequiescentcurrentoftheconvertertojust1.6µAtypical.
This greatly improves overall power conversion efficiency
when the output load is light. Since the converter is not
operatinginsleep, theoutputvoltagewillslowlydecayata
rate determined by the output load current and the output
capacitorvalue. Whentheoutputvoltagehasdecayedbya
small amount, the LTC3130/LTC3130-1 wake and resume
V
Regulator and EXTV Input
CC CC
Aninternallowdropoutregulator(LDO)generatesanomi-
nal 4V V rail from V , or from EXTV if a valid EXTV
CC
IN
CC
CC
voltage is present. The V rail powers the internal control
CC
circuitry and the gate drivers of the LTC3130/LTC3130-1.
The V regulator is enabled even in shutdown, but will
CC
regulate to a lower voltage. The V regulator includes
CC
current-limit protection to safeguard against accidental
short-circuiting of the V rail. V should be decoupled
CC
CC
with a 4.7µF ceramic capacitor located close to the IC.
During start-up, the IC will choose the higher of V or
IN
EXTV togenerateV . OnceV isaboveitsrisingUVLO
normalPWM switchingoperationuntilthevoltageonV
CC
CC
CC
OUT
threshold, EXTV will continue to be used if it is above
is restored to the previous level. If the load is very light,
CC
3.0V typical, otherwise V will be used. This allows start-
the converter may only need to switch for a few cycles to
IN
up from low V sources (in applications where a valid
restore V
and may sleep for extended periods of time,
IN
OUT
EXTV voltage is present), while minimizing LDO power
significantly improving efficiency. If the load is suddenly
increased above the burst transition threshold, the part
willautomaticallyresumecontinuousPWM operationuntil
the load is once again reduced.
CC
dissipation after start-up in applications where V may
IN
be much higher than V .
CC
Use of the EXTV input allows the converter to operate
CC
from V voltages less than 1V, as long as EXTV is held
Note that Burst Mode operation is inhibited until soft-start
is done, the MPPC pin is greater than 1.05V and V
reached 95% of regulation.
IN
CC
initsoperatingrangeof3.0Vminimumand25Vmaximum.
has
OUT
If EXTV is tied to V
in buck applications, it will also
CC
OUT
reducetheinputcurrentdrawnfromV ,therebyincreasing
IN
Soft-Start
converter efficiency, especially at light loads.
TheLTC3130/LTC3130-1soft-startcircuitminimizesinput
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 cur-
rent limit soft-start duration of approximately 12ms. The
internal soft-start circuit slowly ramps the error amplifier
output.Indoingso,themaximumaverageinductorcurrent
is also slowly increased, starting from zero. Soft-start is
resetiftheRUNpindropsbelowtheaccuraterunthreshold,
If an independent source, such as a battery or another
supply rail, is used to power EXTV , then the IC can start
CC
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 V voltage capability
IN
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 V limit is usually around 0.6V, assuming a
IN
V
drops below its UVLO threshold, a thermal shutdown
low resistance source, and that the step-up ratio to V
CC
OUT
occurs, or a peak current limit occurs while V
than 0.7V typical.
is less
doesn’t become duty cycle limited. Refer to the Typical
Performance Characteristic curves for the output voltage
OUT
and current capability versus V .
IN
Note that because the average current limit is being soft-
started, the V rise time will be load dependent, and is
If not used, EXTV should be grounded.
OUT
CC
typically less that 12ms.
3130f
19
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LTC3130/LTC3130-1
OPERATION
Undervoltage Lockout (UVLO)
If RUN is brought below the accurate comparator falling
threshold, the buck-boost converter will inhibit switching,
The V UVLO has a falling voltage threshold of 2.175V
CC
but the V regulator and control circuitry will remain
CC
(typical). If the V voltage falls below this threshold, IC
CC
powered. In this state, the typical V quiescent current is
IN
operation is disabled until V rises above 2.30V (typical).
CC
only 1.4µA, in order to completely shut down the IC and
Therefore, if a valid voltage source is not present on
EXTV , the minimum V for the part to start up is 2.30V
reduce the V current to 500nA (typical), it is necessary
IN
to ensure that RUN is brought below its minimum low
CC
IN
(typical).
logic threshold of 0.2V.
Note that until V is above the UVLO threshold, the part
RUN can be tied directly to V to continuously enable the
CC
IN
willremaininalowquiescentcurrentstate(1.4µAtypical).
IC when the input supply is present. Also note that RUN
This facilitates start-up from very weak sources.
can be driven above V or V
as long as it stays within
IN
OUT
the absolute maximum rating of 25V.
RUN Pin Comparator
TheconverterisenabledwhenthevoltageonRUNexceeds
1.05V (nominal). Therefore, the turn-on voltage threshold
When RUN is driven above its logic threshold (0.6V typi-
cal), the internal voltage reference and the PGOOD circuit
on V is given by:
IN
are enabled (assuming V is above 2.30V typical). If the
CC
R3
R4
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.
V
=1.05V • 1+
IN(TURNON)
Once the converter is enabled, the RUN comparator
includes a built-in hysteresis of 100mV, so that the turn-
off threshold will be :
R3
R4
Therefore, with the addition of an optional resistor divider
as shown in Figure 3, the RUN pin can be used to estab-
lish user-programmable turn-on and turn-off (UVLO)
thresholds. Thisfeaturecanbeutilizedtominimizebattery
drain below a programmed input voltage, or to operate the
converterinahiccupmodefromverylowcurrentsources.
V
= 0.95V • 1+
IN(TURNOFF)
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.
LTC3130
V
ACCURATE THRESHOLD
IN
1.05V
–
+
ENABLE SWITCHING
R3
RUN
PGOOD Comparator
The LTC3130/LTC3130-1 provide an open-drain PGOOD
+
–
R4
ENABLE V
REF
outputthatpullslowifFB(LTC3130)orV
(LTC3130-1)
OUT
AND PGOOD
0.6V
falls more than 7.5% (typical) below its programmed
value. When V rises to within 5% (typical) of its
LOGIC THRESHOLD
OUT
3130 F03
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
Figure 3. Accurate RUN Pin Comparator
3130f
20
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LTC3130/LTC3130-1
OPERATION
nuisance trips of PGOOD due to short transients on V
.
The MPPC divider resistor values can be in the MΩ range
so as to minimize the input current in very low power ap-
plications. However, stray capacitance and noise pickup
on the MPPC pin must also be minimized. If the MPPC
OUT
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.
functionisnotrequired,theMPPCpinshouldbetiedtoV .
CC
NotethatPGOODwillbedrivenlowifV isbelowitsUVLO
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.
CC
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 V or V ,
IN
CC
Note that because Burst Mode operation will be inhibited
if the MPPC loop takes control, the converter will be op-
erating in fixed frequency mode, and will therefore require
a minimum of about 6mA of continuous input current to
operate.Foroperationfromweakersources,suchassmall
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 provid-
this will add to the V quiescent current in shutdown and
IN
UVLO, when PGOOD is low. For the lowest possible V
IN
current in shutdown or UVLO, PGOOD should be pulled
up to V or some other source.
OUT
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 main-
tain a minimum input voltage when using high resistance
sources, such as photovoltaic panels, so as to maximize
ing an effective MPPC function by maintaining V at the
IN
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).
input power transfer and prevent V from dropping too
IN
V
IN
low under load.
C
IN
R5
R6
R
S
V
IN
LTC3130
ReferringtoFigure4, theMPPCpinisinternallyconnected
MPPC
+
–
+
to the noninverting input of a g amplifier, whose invert-
m
V
SOURCE
ing 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
–
1.0V
V
+
–
C
CURRENT
FB
COMMAND
VOLTAGE
ERROR AMP
and regulate V to the programmed minimum voltage,
IN
as given by:
3130 F04
R5
R6
Figure 4. MPPC Amplifier with External Resistor Divider
V
=1.00V • 1+
IN(MPPC)
Note that external compensation should not be required
for MPPC loop stability if the input filter capacitor, C ,
IN
is at least 22µF.
3130f
21
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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.
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
The appropriate selection of external components is de-
pendent 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 de-
sign of the applications circuit, as well as more application
circuit examples.
and 15µH, depending on V and V . Buck mode only
IN
OUT
applications can use the larger inductor values as they
are unaffected by the RHP zero, while mostly boost ap-
plications 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
shouldbeselectedsuchthatitisgreaterthantheworst-case
averageinductorcurrentplushalfoftheripplecurrent.The
peak-to-peak inductor current ripple for each operational
modecanbecalculated fromthefollowingformula, where
f is the switching frequency (1.2MHz), L is the inductance
V
CC
Capacitor Selection
in µH and t
is the switch pin minimum low time in
LOW
The V output of the LTC3130/LTC3130-1 is generated
CC
µs. The switch pin minimum low time is typically 0.07µs.
from V or EXTV by a low dropout linear regulator. The
IN
CC
V
regulator has been designed for stable operation with
CC
VOUT V – V
1
f
IN
OUT
∆IL(P-P)(BUCK)
=
– t
Amps
Amps
a wide range of output capacitors. For most applications,
LOW
L
V
IN
a low ESR capacitor of at least 4.7µF should be used. The
capacitor should be located as close to the V pin as pos-
V
L
VOUT – V
1
CC
IN
IN
∆IL(P-P)(BOOST)
=
– t
LOW
sible and connectedtotheV pinand groundthrough the
CC
CC
VOUT
f
shortest traces possible. V is the regulator output and
is also the internal supply pin for the IC control circuitry
It should be noted that the worst-case peak-to-peak in-
ductor ripple current occurs when the duty cycle in buck
as well as the gate drivers and boost rail charging diodes.
mode is minimum (highest V ) and in boost mode when
IN
Inductor Selection
the duty cycle is 50% (V
IN
= 2 • V ). As an example, if
OUT
IN
V (minimum) = 2.5V and V (maximum) = 15V, V
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 resis-
tance or output current capability and efficiency will be
compromised. Larger inductor values reduce inductor
currentripplebutdonotincreaseoutputcurrentcapability
asisthecasewithpeakcurrentmodecontrol.Largervalue
inductors also tend to have a higher DC series resistance
IN
OUT
= 5V and L = 10µH, the peak-to-peak inductor ripples at
the voltage extremes (15V V for buck and 2.5V V for
IN
IN
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
selectthepropersaturationcurrentratingfortheinductor.
3130f
22
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
APPLICATIONS INFORMATION
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.
To minimize core losses and to prevent high inductor cur-
rent ripple from tripping the peak current limit before the
average current limit is reached, an inductor value with a
�I of less than 500mA P-P should be chosen. For loads
L
Table 2. Recommended Inductors
thatoperatewellbelowcurrentlimit,higherinductorripple
VENDOR
PART NUMBER FAMILY
can be tolerated to allow the use of a lower value inductor.
Coilcraft
coilcraft.com
EPL3015, LPS3314, LPS4012, LPS4018,
XFL3012, XFL4020, MSS4020
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).
Coiltronics
cooperindustries.com
SD3814, SD3118, SD52
Murata
murata.com
LQH43P, LQH44P
Sumida
sumida.com
CDRH2D18, CDRH3D14, CDRH3D16,
CDRH4D14
Note that in boost mode, especially at large step-up ra-
tios, 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 out-
put current capability from what is shown in the Typical
Performance Characteristics section and from the Typical
Application circuits.
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.
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 maxi-
mum 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 ef-
ficiency 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.
Table 3. Recommended Inductor and
Output Capacitor Values
MINIMUM RECOMMENDED OUTPUT CAPACITANCE (μF)
V
L
LTC3130-1/LTC3130
LTC3130
OUT
MAX
(V)
(μH) WITH FEED FORWARD PWM AND NO FEED-FORWARD
1 – 2.4
4.7
40
30
20
20
10
20
15
10
10
5
Differentinductorcorematerialsandstyleshaveanimpact
on the size and price of an inductor at any given current
rating. Shielded construction is generally preferred as it
minimizesthechancesofinterferencewithothercircuitry.
Thechoiceofinductorstyledependsupontheprice,sizing,
and EMI requirements of a particular application.
2.5 – 3.9 6.8
4 – 6.5 10
6.6 – 14 15
14 – 25 15
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.
Table2providesawidesamplingofinductorfamiliesfrom
different manufacturers that are well suited to LTC3130/
LTC3130-1 applications. However, be sure to check the
3130f
23
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
APPLICATIONS INFORMATION
Output Capacitor Selection
the series resistance of the output capacitor and all other
terms as previously defined:
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 volt-
age 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
ILOAD ESR
R
∆V
=
≅ ILOAD ESR
R
Volts
P-P(BUCK)
1– tLOW
f
ILOAD ESR OUT
R
V
∆V
=
P-P(BOOST)
V 1– t
f
(
)
IN
LOW
VOUT
≅ ILOAD ESR
R
Volts
V
IN
frequency in MHz (1.2MHz), C
is the capacitance in µF,
In most LTC3130/LTC3130-1 applications, an output
capacitor between 10µF and 47µF will work well. To mini-
mize output ripple in Burst Mode operation, or transients
incurred by large step loads, values of 22µF or larger are
recommended.
OUT
t
is the switch pin minimum low time in µs (0.07µs)
LOW
and I
is the output current in Amps:
LOAD
ILOAD LOW
t
∆V
=
Volts
– VIN + tLOWfV
P-P(BUCK)
COUT
ILOAD
fC
Input Capacitor Selection
V
IN
OUT
∆V
=
Volts
P-P(BOOST)
The PV pin carries the full inductor current, while the V
VOUT
IN
IN
OUT
pin provides power to internal control circuits in the IC. To
minimize input voltage ripple and ensure proper opera-
tion of the IC, a low ESR bypass capacitor with a value of
Examining the previous equations reveal that the output
voltage ripple increases with load current and is gener-
ally 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
rippleatanysignificantloadcurrentbutunderestimatethe
output voltage ripple at very light loads where the output
voltage ripple is dominated by the inductor current ripple.
at least 4.7µF should be located as close to the PV pin
IN
as possible. The V pin should be bypassed with a 1μF
IN
ceramic capacitor located close to the pin, and Kelvined
to “quiet side” of the primary V decoupling capacitor.
IN
Do not tie the V pin directly to PV pin.
IN
IN
Whenpoweredthroughlongleadsorfromapowersource
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.
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
proportionaltotheseriesresistanceoftheoutputcapacitor
and is given by the following expressions where R
is
ESR
For applications using the MPPC feature, a minimum C
IN
capacitor value of 22µF is recommended. Larger values
can be used without limitation.
3130f
24
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
APPLICATIONS INFORMATION
Recommended Input and Output Capacitor Types
value capacitance or a higher voltage rated capacitor than
wouldordinarilyberequiredtoactuallyrealizetheintended
capacitanceattheoperatingvoltageoftheapplication.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.
The capacitors used to filter the input and output of the
LTC3130/LTC3130-1 must have low ESR and must be
ratedtohandletheACcurrentsgeneratedbytheswitching
converter.Thisisimportanttomaintainproperfunctioning
of the IC and to reduce output voltage ripple. There are
many capacitor types that are well suited to these appli-
cations 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.
Using the Programmable RUN Function to Operate
from Extremely Weak Input Sources
Another application of the programmable RUN pin is
that it can be used to operate the converter in a “hiccup”
modefromextremelyweaksources.Thisallowsoperation
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
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 volt-
age ripple is generally not a concern.
typical from V until they are enabled, the RUN pin can be
IN
programmedtokeeptheICsdisableduntilV reachesthe
IN
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 op-
eration. 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.
programmedvoltagelevel.Inthismanner,theinputsource
can trickle-charge an input storage capacitor, even if it can
only supply microamps of current, until V reaches the
IN
turn-onthresholdsetbytheRUNpindivider.Theconverter
will then be enabled, using the stored charge in the input
capacitor to power the converter and bring up V , until
OUT
V drops below the turn-off threshold, at which point the
IN
Beware of Capacitor DC Bias Effect
converter will turn off and the process will repeat.
Ceramic capacitors are often utilized in switching con-
verter 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 light-
ing. 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 (with10% ripple as set by the UVLO
hysteresis) about a fixed voltage, as determined by the
divider. This allows the high impedance source to oper-
ate about the programmed optimal voltage for maximum
power transfer.
3130f
25
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
APPLICATIONS INFORMATION
Inthese“trickle-charge”applications,alargerinputcapaci-
For example, if V
is 5V, with a pulsed load of 25mA
OUT
tor is generally required. If the load on V
is extremely
for a duration of 5ms, and V has been programmed for
OUT
IN
light, such that the available steady-state input power can
sustain V , then the input capacitor simply has to have
a rising UVLO threshold of 12V, then the minimum C
IN
capacitor required, assuming a conversion efficiency of
85%, would be 53.7µF, so a 68µF input capacitor would
be recommended.
OUT
enough charge to bring V
into regulation before V
OUT
IN
discharges below the falling UVLO threshold (assuming
that the goal is to charge up V in a single “burst” and
OUT
When using high value RUN pin divider resistors (in the
MΩ range) to minimize current draw on V , a small noise
then maintain V
regulation). In this case, the minimum
value required for C can be determined by:
OUT
IN
IN
filter capacitor may be necessary across the lower divider
resistor to prevent noise from erroneously tripping the
RUNcomparator.Thecapacitorvalueshouldbeminimized
(10pF may do) so as not to introduce a time delay long
enough for the input voltage to drop significantly below
the desired V threshold. Note that larger V decoupling
2
COUT •VOUT
CIN(MIN)
>
2
η V 2 – 0.9•V
(
)
(
IN
IN
)
(
)
where V is the programmed rising UVLO threshold and
IN
IN
IN
capacitorvalueswillminimizethiseffectbyprovidingmore
ηistheaverageconversionefficiency, givenV andV
.
IN
OUT
holdup time on V .
It can be seen that a larger C
capacitor will require a
IN
OUT
larger C capacitor to charge it.
IN
Use of the EXTV Input
CC
The time required for the C capacitor to charge up to the
IN
As discussed in the Operation section of this data sheet,
V rising UVLO threshold (starting from zero volts) is:
IN
theLTC3130/LTC3130-1includeanEXTV inputthatcan
CC
CIN µF •V
( )
µA –1.4µA –I
CHARGE ( )
IN(UVLO)
be used to provide V for the IC, allowing start-up and/
CC
tCHARGE
where I
( )
sec =
I
(
µA
( )
or operation in applications where V is below the V
)
IN
CC
LEAK
UVLO threshold, all the way down to less than 1V.
is the leakage of the input capacitor in µA at
the programmed V UVLO voltage.
LEAK
Possible sources that could be used to power the EXTV
CC
IN
input would include V
(if V
is programmed for at
OUT
OUT
For applications where V
must remain in regulation
least 3.15V and if V is at least 2.4V to start), or an inde-
OUT
IN
during a pulsed load for a given period of time, the input
pendent voltage rail that may be available in the system,
capacitorvaluerequiredwillbedictatedbytheprogrammed
or even a battery.
V andV ,andthedurationandmagnitudeoftheoutput
IN
OUT
The requirements for the EXTV voltage are that it is a
CC
load current, as given by:
minimum of 3.0V typical, and an absolute maximum of
IOUT •VOUT •2•t
25V. It must also be able to supply a minimum of 6mA
CIN(MIN)
>
of current. If the source of EXTV is not very close to
η V 2 – 0.9•V
2
CC
(
)
(
IN
IN
)
(
)
the IC, then a decoupling capacitor of 4.7µF minimum is
recommended at the EXTV pin.
CC
where C is in micro Farads, I
is the average load
IN
OUT
In the case of using a battery to power EXTV , the battery
CC
current in milliamps for duration t in milliseconds. V
IN
lifeforcontinuoussteady-stateoperationinfixedfrequency
is the programmed rising UVLO threshold and η is the
average conversion efficiency, given V and V . This
mode can be estimated by:
IN
OUT
calculation assumes that the V
capacitor has already
OUT
OUT
Battery Life (Hours) = Battery Capacity (mA-Hr)/6mA
been charged, and that the load on V
before and after
the load pulse is low enough as to be sustained by the
available steady-state input power.
3130f
26
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.
periodically trying to start switching, as it goes in and out
of UVLO. If EXTV is held above 3.0V, this will not occur.
CC
In applications where the V and EXTV voltages are
IN
CC
such that this scenario could occur, the RUN pin can be
used to monitor the EXTV input and inhibit operation
CC
whenever EXTV is below 3.15V. An example of this is
CC
shown in Figure 6.
EXTV
CC
ForapplicationswhereV willbegreaterthanthebattery
LTC3130
OUT
voltage, and at least 3.6V, a battery and a dual Schottky
1.05V
2M
–
+
+
V
ENABLE
SWITCHING
RUN
diode can be used to get the part started at low V . After
V
IN
EXT
–
1M
start-up, the IC will be powered from V , so there will
OUT
be no steady-state current draw on the battery. In this
case, the battery life may approach its shelf life (even in
continuousfixedfrequencyoperation).Inshutdown,there
will be about 0.5uA of current draw from the battery. An
example of this configuration is shown in Figure 5.
3130 F06
Figure 6. Using the RUN Pin to Set the Minimum Voltage
for EXTVCC to 3.15V
Programming the MPPC Voltage
V
OUT
PV
V
V
OUT
IN
4V TO 25V
BAT54C
As discussed in the previous section, the LTC3130/
LTC3130-1 include an MPPC function to optimize perfor-
mancewhenoperatingfromvoltagesourceswithrelatively
high source resistance. Using an external voltage divider
+
C
OUT
IN
V
LTC3130/
LTC3130-1
IN
V
1V TO 25V
–
EXTV
RUN
EXTV
CC
CC
+
4.7µF
3.6V
SGND
from V , the MPPC function takes control of the average
IN
3031 F05
inductor current when necessary to maintain a minimum
input voltage, as programmed by the user. Referring to
Figure 3:
Figure 5. Using a Battery Just for Start-Up from Low VIN
Note that during start-up, when V is still in UVLO, the IC
CC
R5
R6
chooses the higher of V or EXTV to power V (even
V
=1.0V • 1+
IN
CC
CC
IN(MPPC)
if EXTV is below 3.0V). After start-up however, when
CC
V
CC
has risen above its rising UVLO threshold, the IC
This is useful for such applications as photovoltaic pow-
ered converters, since the maximum power transfer point
occurs when the photovoltaic panel is operated at about
75%ofitsopen-circuitvoltage.Forexample,whenoperat-
ing 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
will choose to use the EXTV input to power V only if
CC
CC
EXTV is above 3.0V, typical. This is done to avoid using
CC
EXTV at a very low voltage when a higher voltage may
CC
be available at V .
IN
Therefore, there could be a situation where the IC would
switch between using EXTV during start-up, and V as
CC
IN
the source for V after start-up. However, if V is below
CC
IN
the UVLO threshold, V will drop and revert to using
CC
EXTV again. This cycling will only occur if V is below
regulate the maximum input current so as to maintain V
CC
IN
IN
the UVLO falling threshold and EXTV is greater than the
at a minimum of 3.73V (typical). Note that if the panel can
providemorepowerthantheapplicationrequires,theinput
voltage will rise above the programmed MPPC point. This
is fine as long as the input voltage doesn’t exceed 25V.
CC
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
3130f
27
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
APPLICATIONS INFORMATION
Forweakinputsourceswithveryhighresistance(hundreds
Thermal Considerations
ofOhmsormore),theLTC3130/LTC3130-1maystilldraw
The power switches of the LTC3130/LTC3130-1 are de-
signed to operate continuously with currents up to the
internalcurrentlimitthresholds.However,whenoperating
at high current levels, there may be significant heat gener-
ated 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
thattheLTC3130/LTC3130-1isabletoprovideitsfull-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
underneaththeICpackagetootherPCBlayer(s)containing
a large copper plane. A typical board layout incorporating
these concepts in show in Figure 7.
more current than the source can provide, causing V to
IN
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.
Primarilythesearetheinputcapacitance,theMPPCresistor
divider ratio and the V source resistance. To simplify the
IN
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 V capacitor of at
IN
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).
As described elsewhere in this data sheet, the EXTV
CC
pin may be used to reduce the V power dissipation
CC
term significantly in high V applications, lowering die
IN
temperature and improving efficiency.
If the IC die temperature exceeds approximately 165°C,
overtemperatureshutdownwillbeinvokedandallswitching
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.
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.
Applications with Low V and V
IN
OUT
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
Table 4. Small Photovoltaic Panel Manufacturers
from the addition of Schottky diode from SW2 to V
.
Sanyo
panasonic.net
powerfilmsolar.com
ixys.com
OUT
Diodes such as an MBR0530 or equivalent are recom-
mended for these applications.
PowerFilm
Ixys
Corporation
G24
Innovations
gcell.com
3130f
28
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
APPLICATIONS INFORMATION
LTC3130
L1
CBST2
RPGD
CBST1
V
IN
V
OUT
GND
GND
C
IN
C
OUT
CE T
X
CV
CC
R2 R1
LTC3130-1
L1
CBST2
RPGD
CBST1
V
IN
V
OUT
GND
GND
C
IN
C
OUT
CE T
X
CV
CC
8603 F07
Figure 7. Typical 2-Layer PC Board Layout (QFN Package Shown)
3130f
29
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
APPLICATIONS INFORMATION
22nF
22nF
4.7µH
V
OP
= 5V
OC
BST1 SW1
SW2 BST2
V
= 3.5V
V
OUT
V
PV
V
OUT
IN
IN
4.4V
100k
+
+
4.7µF
4.7µF
V
IN
100F
EXTV
CC
RUN
4.99M
3.4M
1M
LTC3130
MPPC
PGOOD
FB
100k
47µF
PV
PANEL
100F
V
CC
ILIM
1µF
2M
TECATE
MODE
V
CC
TPL-100/22x45F
GND
PGND
3130 F08
Figure 8. Outdoor Solar Panel Powered, 600mA Supercapacitor Charger Using MPPC
22nF
22nF
10µH
BST1 SW1
SW2 BST2
V
OUT
24V
V
PV
IN
V
OUT
IN
20mA
10µF
V
IN
10pF
1M
PGOOD
EXTV
CC
RUN
4.02M
174k
LTC3130
+
10µF
3.6V
Li-SOCI2
V
CC
MPPC
PGOOD
FB
200k
ILIM
1µF
MODE
V
CC
GND
PGND
4.7µF
3130 F09
Figure 9. Battery-Powered 24V Converter with 200mA ILIM to Limit Battery Droop
3130f
30
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
APPLICATIONS INFORMATION
22nF
22nF
10µH
V
OUT
BST1 SW1
PV
SW2 BST2
V
IN
15V
2.4V TO 25V
V
IN
OUT
500mA
10µF
10pF
(V > 15V)
IN
V
IN
EXTV
CC
RUN
4.99M
357k
LTC3130
10µF
249k
MPPC
PGOOD
FB
V
CC
ILIM
1µF
MODE
V
CC
GND
PGND
4.7µF
3130 F10
Figure 10. Wide VIN Range 15V Converter with Burst Mode Operation
22nF
22nF
6.8µH
V
OUT
BST1 SW1
PV
IN
SW2 BST2
V
IN
5V
V
0.95V TO 25V
OUT
500mA
(V > 5V)
(2.4V TO START)
22µF
V
IN
IN
EXTV
CC
RUN
1M
LTC3130-1
V
MPPC
MODE
CC
10µF
PGOOD
PGOOD
VS1
VS2
1µF
V
CC
GND
PGND
4.7µF
3130 F11
Figure 11. Low Noise, Wide VIN Range 5V Converter
3130f
31
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
APPLICATIONS INFORMATION
MBR0520
I
I
I
UP TO 600mA WHEN OPERATING FROM WALL ADAPTER
UP TO 500mA WHEN OPERATING FROM USB 3.0 INPUT
UP TO 300mA WHEN OPERATING FROM BATTERY
OUT
OUT
OUT
22nF
22nF
12V WALL ADAPTER INPUT
B130
6.8µH
USB 3.0 INPUT
BST1 SW1
SW2 BST2
V
OUT
PV
V
OUT
IN
BSS314
5V
22µF
V
IN
RUN
EXTV
CC
1M
LTC3130-1
V
GATE
LTC4412
IN
10µF
V
V
MPPC
MODE
CC
PGOOD
PGOOD
SENSE
STAT
GND
+
VS1
VS2
Li-Ion
1µF
CTL
V
CC
CC
GND
PGND
4.7µF
3130 F12
Figure 12. Multiple VIN 5V Out Application, Using the LTC4412 PowerPath™ Controller
22nF
22nF
6.8µH
V
= 8V
698k
BST1 SW1
SW2 BST2
V
MPPC
OUT
12V
V
IN
PV
IN
V
OUT
100mA MIN
10µF
V
IN
RUN
EXTV
CC
10Ω
LTC3130-1
+
MPPC
MODE
22µF
PGOOD
10V
TO
14V
1µF
CC
V
VS1
VS2
V
CC
100k
GND
PGND
4.7µF
3130 F13
Figure 13. 12V Converter Uses MPPC Function to Maintain a Minimum VIN from a Current Limited Source
3130f
32
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
APPLICATIONS INFORMATION
22nF
22nF
6.8µH
D1*
BST1 SW1
PV
IN
SW2 BST2
DC SOURCE
V
OUT
V
<0.9V TO 25V
OUT
3.3V
(2.4V + V
D1
V
47µF
IN
TO START)
RUN
EXTV
CC
4.7µF
LTC3130-1
V
+
MPPC
MODE
470µF
25V
×2
CC
PGOOD
VS1
VS2
V
CC
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
22nF
6.8µH
UVLO THRESHOLDS
11.55V/0.95V
BAS70-05
BST1 SW1
SW2 BST2
V
OUT
PV
IN
V
OUT
5V
V
22µF
IN
10M
INPUT SOURCES:
LTC3130-1
RUN
EXTV
CC
47µF
16V
RF
AC
PIEZO
V
CC
MPPC
MODE
CER
PGOOD
1M
×2
COIL-MAGNET
BAS70-06
VS1
VS2
1µF
V
CC
GND
PGND
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
33
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
TYPICAL APPLICATIONS
22nF
22nF
6.8µH
V
IN
BST1 SW1
PV
IN
SW2 BST2
UVLO = 11.41V
4.99M
V
4 Li-Ion
OUT
12V
V
OUT
500mA
V
IN
10µF
RUN
EXTV
CC
LTC3130-1
+
V
CC
MPPC
MODE
10µF
PGOOD
453k
VS1
V
CC
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
V
V
OUT
V
IN
OUT1
3.3V
LTC3525-3.3
SHDN
GND
4.7µF
2.2µF
22nF
22nF
1.5µH
BST1 SW1
PV
SW2 BST2
V
OUT2
V
IN
V
IN
OUT
1.2V
47µF
100pF
V
IN
RUN
EXTV
CC
402k
2M
LTC3130
10µF
20k
V
MPPC
ILIM
PGOOD
FB
CC
ALKALINE
OR NiMH
0.85V to 1.5V
+
1µF
MODE
V
CC
GND
PGND
4.7µF
3130 F17
Figure 17. Single-Cell 1.2V, 200mA Buck Boost Converter,
Using the LTC3525-3.3 to Provide the EXTVCC Bias Supply
3130f
34
For more information www.linear.com/LTC3130
LTC3130/LTC3130-1
TYPICAL APPLICATIONS
BAT54S
1μF
22nF
22nF
3.3µH
BST1 SW1
PV
IN
SW2 BST2
V
V
IN
V
OUT
<0.9V TO 25V
OUT
1.80V
(2.4V TO START)
V
47µF
IN
4.7µF
RUN
10µF
LTC3130-1
EXTV
CC
V
MPPC
MODE
CC
PGOOD
1µF
VS1
VS2
V
CC
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
22nF
6.8µH
BST1 SW1
SW2 BST2
V
IN
V
OUT
0.95V TO 25V
PV
IN
V
OUT
3.6V
(2.4V TO START)
47µF
15pF
V
IN
RUN
EXTV
CC
10µF
2.61M
1M
LTC3130
V
MPPC
ILIM
PGOOD
FB
CC
1µF
100k
200mA 600mA
MODE
V
CC
GND
PGND
4.7µF
3130 F19
Figure 19. Wide VIN Range 3.6V Converter with Two Programmed Current Limit Levels
3130f
35
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.
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
PIN 1 NOTCH
R = 0.20 OR 0.25
× 45° CHAMFER
0.75 ±0.05
1.50 REF
19 20
R = 0.05 TYP
3.00 ±0.10
0.40 ±0.10
1
PIN 1
TOP MARK
(NOTE 6)
2
2.65 ±0.10
1.65 ±0.10
4.00 ±0.10
2.50 REF
(UDC20) QFN 1106 REV Ø
0.200 REF
0.00 – 0.05
0.25 ±0.05
R = 0.115
TYP
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
3130f
36
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)
2.845 ±0.102
(.112 ±.004)
0.889 ±0.127
(.035 ±.005)
1
8
0.35
REF
5.10
(.201)
MIN
1.651 ±0.102
(.065 ±.004)
1.651 ±0.102
(.065 ±.004)
3.20 – 3.45
(.126 – .136)
0.12 REF
DETAIL “B”
CORNER TAIL IS PART OF
THE LEADFRAME FEATURE.
FOR REFERENCE ONLY
DETAIL “B”
16
9
0.305 ±0.038
0.50
(.0197)
BSC
NO MEASUREMENT PURPOSE
4.039 ±0.102
(.159 ±.004)
(NOTE 3)
(.0120 ±.0015)
TYP
0.280 ±0.076
(.011 ±.003)
RECOMMENDED SOLDER PAD LAYOUT
16151413121110
9
REF
DETAIL “A”
0.254
(.010)
3.00 ±0.102
(.118 ±.004)
(NOTE 4)
0° – 6° TYP
4.90 ±0.152
(.193 ±.006)
GAUGE PLANE
0.53 ±0.152
(.021 ±.006)
1 2 3 4 5 6 7 8
DETAIL “A”
0.86
(.034)
REF
1.10
(.043)
MAX
0.18
(.007)
SEATING
PLANE
0.17 – 0.27
(.007 – .011)
TYP
0.1016 ±0.0508
(.004 ±.002)
MSOP (MSE16) 0213 REV F
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.
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 representa-
37
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
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
22nF
6.8µH
BST1 SW1
SW2 BST2
V
V
IN
OUT
PV
V
V
OUT
IN
0.95V TO 25V
5V
22µF
BAT54C
4.7µF
IN
STOP RUN
RUN
EXTV
CC
LTC3130-1
V
CC
MPPC
MODE
1µF
PGOOD
+
VS1
VS2
10µF
3.6V
TADIRAN TL-4902
V
V
CC
CC
GND
PGND
4.7µF
3130 TA02
RELATED PARTS
V
V
OUT
RANGE (V)
IN
PART
DESCRIPTION
RANGE (V)
I (μA)
Q
PACKAGE
LTC3129/LTC3129-1
15V, 200mA, 1.2MHz, 95% Efficient Monolithic
Synchronous Buck/Boost
2.42V to 15V
2.7V to 40V
2.2V to 40V
2.7V to 15V
1.8V to 5.5V
1.8V to 5.5V
1.8V to 5.5V
2.2V to 18V
1.4V to 15.75V
2.7V to 40V
2.7V to 40V
2.7V to 14V
2V to 5V
1.3µA
30µA
30µA
50µA
16µA
25µA
40µA
50µA
3mm × 3mm
QFN-16/MSOP-16E
LTC3115-1/LTC3115-2 40V, 2A, 2MHz, 95% Efficient Monolithic
Synchronous Buck/Boost
4mm × 5mm
DFN-16/TSSOP-20E
LTC3114-1
LTC3112
LTC3531
LTC3122
LTC3113
LTC3118
40V, 1A, 1.2MHz, 95% Efficient Monolithic
Synchronous Buck/Boost
3mm × 5mm
DFN-16/TSSOP-16E
15V, 2.5A, 750kHz, 95% Efficient Monolithic
Synchronous Buck/Boost
4mm × 5mm
DFN-16/TSSOP-20E
5.5V, 200mA, 600kHz Monolithic Synchronous
Buck/Boost
3mm × 3mm
DFN-8/ThinSOT
15V, 2.5A, 3MHz, 95% Efficient Monolithic
Synchronous Buck/Boost
2.2V to 15V
1.8V to 5.5V
2.2V to 18V
3mm × 4mm
DFN-12/MSOP-12E
5V, 3A, 2MHz, 96% Efficient Monolithic Synch
Buck/Boost
4mm × 5mm
DFN-16/TSSOP-20E
Dual Input 18V, 2A, 1.2MHz, 95% Efficient
Monolithic Synchronous Buck/Boost with
PowerPath Control
4mm × 5mm
QFN-24/TSSOP-28E
LTC3111
1.5A (I ), 15V Synchronous Buck-Boost
2.5V to 15V
2.5V to 15V
49µA
3mm × 4mm
DFN-14/MSOP-16
OUT
DC/DC Converter
3130f
LT 0816 • PRINTED IN USA
LinearTechnology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
38
●
●
LINEAR TECHNOLOGY CORPORATION 2016
(408)432-1900 FAX: (408) 434-0507 www.linear.com/LTC3130
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