LTC3130/LTC3130-1
1
3130f
For more information www.linear.com/LTC3130
TYPICAL APPLICATION
FEATURES DESCRIPTION
25V, 600mA Buck-Boost
DC/DC Converter with
1.6µA Quiescent Current
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,
BurstMode operation can be selected, reducing the quies-
cent 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 photo-
voltaic 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 thermally-
enhanced 20-lead 3mm × 4mm QFN and 16-lead MSOP
packages.
APPLICATIONS
n Regulates VOUT Above, Below or Equal to VIN
n Wide VIN Range: 2.4V to 25V,
<1V to 25V (Using EXTVCC Input)
n VOUT Range: 1V to 25V
n Adjustable Output Voltage (LTC
®
3130)
n Four Selectable Fixed Output Voltages (LTC3130-1)
n 1.2µA No-Load Input Current in Burst Mode
®
Operation (VIN = 12V, VOUT = 5V)
n 600mA Output Current in Buck Mode
n Pin-Selectable 850mA/450mA Current Limit (LTC3130)
n Up to 95% Efficiency
n Pin-Selectable Burst Mode Operation
n 1.2MHz Ultralow Noise PWM Frequency
n Accurate RUN Pin Threshold
n Power Good Indicator
n Programmable Maximum Power Point Control
n IQ = 500nA in Shutdown
n Thermally-Enhanced 20-Lead 3mm × 4mm QFN and
16-Lead MSOP Packages
n Long-Life, Battery-Operated Instruments
n Portable Military Radios
n Low Power Sensors
n Solar Panel Post-Regulator/Charger
L, LT , LT C , LT M , 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.
Efficiency vs Load
V
IN
= 14.4V, V
OUT
= 12V
LOAD (mA)
0.01
0.1
1
10
100
800
0
10
20
30
40
50
60
70
80
90
100
EFFICIENCY (%)
3130 TA01b
BST1 BST2
PVIN
VIN
VCC
3130 TA01a
VIN
4 Li-Ion
VOUT
RUN
MPPC
MODE
VS1
VS2
PGOOD
VCC
10µF
4.7µF
10µF
VOUT
12V
600mA
EXTVCC
SW1 SW2
GND PGND
22nF22nF 6.8µH
LTC3130-1
+
LTC3130/LTC3130-1
2
3130f
For more information www.linear.com/LTC3130
PIN CONFIGURATION
ABSOLUTE MAXIMUM RATINGS
PVIN , VIN, VOUT Voltage .............................–0.3 to 27.5 V
EXTVCC Voltage .........................................–0.3 to 27.5V
BST1, BST2 Voltage ............... (SW – 0.3V) to (SW + 6V)
RUN, PGOOD Voltage .................................–0.3 to 27.5 V
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
(Notes 1, 8)
ORDER INFORMATION
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC3130EUDC#PBF LTC3130EUDC#TRPBF 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 LT C 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.
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
20 19 18 17
7 8
TOP VIEW
21
GND
UDC PACKAGE
20-LEAD (3mm × 4mm) PLASTIC QFN
9 10
6
5
4
3
2
1
11
12
13
14
15
16
BST1
PVIN
VIN
RUN
VCC
MPPC
BST2
SW2
VOUT
PGOOD
EXTVCC
MODE
SW1
PGND
PGND
NC
GND
GND
VS2/FB
VS1/ILIM
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
1
2
3
4
5
6
7
8
GND
BST1
SW1
PVIN
VIN
RUN
VCC
MPPC
16
15
14
13
12
11
10
9
SW2
BST2
VOUT
PGOOD
EXTVCC
MODE
VS1/ILIM
VS2/FB
TOP VIEW
17
GND
MSE PACKAGE
16-LEAD PLASTIC MSOP
TJMAX = 125°C, θJA = 40°C/W, θJC = 10°C/W (NOTE 6)
EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB
http://www.linear.com/product/LTC3130#orderinfo
LTC3130/LTC3130-1
3
3130f
For more information www.linear.com/LTC3130
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 MAX UNITS
VIN Start-Up Voltage EXTVCC = 0V
EXTVCC > 3.15V, RUN > 1.1V
l
l
2.30
0.6
2.40
1.0
V
V
Input Voltage Range EXTVCC > 3.15V, RUN > 1.1V l0.6 25 V
Output Voltage Adjust Range (LTC3130) l1.0 25 V
Feedback Voltage (LTC3130) For External FB Resistor Applications l0.975 1.000 1.020 V
From –40°C to +85°C (Note 3) 0.980 1.000 1.020 V
Feedback Input Current (LTC3130) FB = 1.1V 0.1 10 nA
Fixed VOUT Voltages (LTC3130-1) VS1 = VS2 = 0V
VS1 = VCC, VS2 = 0V
VS1 = 0V, VS2 = VCC
VS1 = VS2 = VCC
l
l
l
l
1.75
3.20
4.85
11.64
1.80
3.3
5.0
12.0
1.85
3.39
5.125
12.30
V
V
V
V
VIN Quiescent Current – Shutdown RUN < 0.2V 500 850 nA
VIN Quiescent Current – UVLO 0.85V < RUN < 0.9V, EXTVCC = 0V 1.4 2.4 µA
VIN Quiescent Current – Burst Mode Operation
(Sleeping)
FB > 1.02V (LTC3130), VOUT > VREG (LTC3130-1),
MODE = 0V, RUN = VIN, MPPC > 1.05V
1.6 2.7 µA
NMOS Switch Leakage on VIN and VOUT SW1 = SW2 = 0V, VIN = VOUT = 25V 5 100 nA
NMOS Switch On-Resistance VCC = 4V 0.35 Ω
Inductor Average Current Limit LTC3130-1 (Note 4), LTC3130: ILIM = VCC (Note 4) l660 850 1200 mA
LTC3130: ILIM = 0V (Note 4) l250 450 650 mA
Inductor Peak Current Limit LTC3130-1 (Note 4), LTC3130: ILIM = VCC (Note 4) l0.9 1.3 1.7 A
LTC3130: ILIM = 0V (Note 4) l0.6 0.85 1.15 A
Maximum Boost Duty Cycle
(Percentage of Period SW2 is Low)
LTC3130-1: VOUT < VREG (Note 7),
LTC3130: FB < 0.975V (Note 7)
l91 94 97 %
Minimum Duty Cycle LTC3130-1: VOUT > VREG (Note 7),
LTC3130: FB > 1.02V (Note 7)
l0 %
Switching Frequency l1.00 1.20 1.40 MHz
SW1 and SW2 Minimum Low Time (Note 3) 70 ns
MPPC Reference Voltage l0.95 1.00 1.05 V
MPPC Input Current MPPC = 5V 1 20 nA
RUN Logic Threshold to Enable Reference l0.2 0.6 0.85 V
RUN Threshold to Enable Switching (Rising) VIN > 2.4V or EXTVCC > 3.15V l1.01 1.05 1.09 V
RUN Threshold Hysteresis l90 100 110 mV
RUN Input Current RUN = 25V
RUN = 1V
1
0.1
30
5
nA
nA
ILIM Input Logic High (LTC3130) l1.1 V
ILIM Input Logic Low (LTC3130) l0.35 V
ILIM Input Current (LTC3130) ILIM = 5V 1 20 nA
VS1, VS2 Input Logic High (LTC3130-1) l1.1 V
VS1, VS2 Input Logic Low (LTC3130-1) l0.35 V
VS1, VS2 Input Current (LTC3130-1) VS1, VS2 = 5V 1 20 nA
MODE Input Logic High l1.1 V
MODE Input Logic Low l0.35 V
MODE Input Current MODE = 5V (If RUN is Low or VCC is in UVLO)
MODE = 5V (If Switching is Enabled)
1
1.7
20
4
nA
µA
LTC3130/LTC3130-1
4
3130f
For more information www.linear.com/LTC3130
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 MAX UNITS
Soft-Start Time For Average Inductor Current to Reach Limit 12 ms
VCC Voltage (EXTVCC or VIN) > 4.7V, RUN > 0.85V 4 V
VCC Voltage -– Shutdown RUN ≤ 0.2V 3.25 V
VCC Dropout Voltage (VIN – VCC) VIN = 3.0V, Switching 50 100 mV
VCC Current Limit VCC = 0V 17 34 mA
VCC UVLO Threshold (Rising) l2.20 2.3 2.40 V
VCC UVLO Hysteresis 100 120 135 mV
EXTVCC Enable Threshold l2.85 3.0 3.15 V
EXTVCC Enable Hysteresis 260 mV
EXTVCC Input Operating Range l3.15 25 V
EXTVCC Quiescent Current – Burst Mode
Operation (Sleeping)
EXTVCC > 3.15V, FB >1.02V (LTC3130), MPPC > 1.05V
VOUT > VREG (LTC3130-1), MODE = 0V, RUN > 1.10V
1.6 2.5 µA
EXTVCC Quiescent Current – Shutdown EXTVCC = 5V, RUN < 0.2V 400 750 nA
EXTVCC Current Limit VCC = 0V, EXTVCC = 15V 32 68 mA
VIN Sleep Current When Powered by EXTVCC FB > 1.02V (LTC3130), VOUT > VREG (LTC3130-1),
EXTVCC > 3.15V, MODE = 0V,
RUN >1.10V, VIN = 12V, MPPC > 1.05V
600 nA
VOUT UV Threshold Rising l0.35 0.7 0.95 V
VOUT UV Hysteresis 55 mV
VOUT Quiescent Current – Shutdown (VOUT–1)
27
(VOUT)
17
µA
VOUT Quiescent Current – Burst Mode
Operation (Sleeping)
MODE = 0V, FB > 1.02V, MPPC > 1.05V (VOUT–1)
27
(VOUT)
17
µA
PGOOD Threshold, Rising Referenced to Programmed VOUT Voltage –7.0 –5.0 –3.0 %
PGOOD Hysteresis Referenced to Programmed VOUT Voltage 2.5 %
PGOOD Voltage Low ISINK = 1mA 165 250 mV
PGOOD Leakage PGOOD = 25V 1 50 nA
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.
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.
LTC3130/LTC3130-1
5
3130f
For more information www.linear.com/LTC3130
TYPICAL PERFORMANCE CHARACTERISTICS
Efficiency, VOUT = 12V,
PWM Mode
Efficiency, VOUT = 1.8V, Burst
Mode Operation (LTC3130-1)
Power Loss, VOUT = 1.8V, Burst
Mode Operation (LTC3130-1)
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)
Efficiency, VOUT = 1.8V,
PWM Mode
Efficiency, VOUT = 3.3V,
PWM Mode
Efficiency, VOUT = 5V,
PWM Mode
TA = 25°C, unless otherwise noted.
LOAD CURRENT (mA)
0.01
0.1
1
10
100
1k
0
10
20
30
40
50
60
70
80
90
100
EFFICIENCY (%)
vs Load, V
OUT
= 1.8V, PWM Mode
3130 G01
V
= 2.5V
V
IN
= 3.6V
V
IN
= 5V
V
IN
= 12V
V
IN
= 24V
IN
LOAD CURRENT (mA)
0.01
0.1
1
10
100
1k
0
10
20
30
40
50
60
70
80
90
100
EFFICIENCY (%)
OUT
3130 G02
V
= 2.5V
V
IN
= 3.6V
V
IN
= 5V
V
IN
= 12V
V
IN
= 24V
IN
LOAD CURRENT (mA)
0.01
0.1
1
10
100
1k
0
10
20
30
40
50
60
70
80
90
100
EFFICIENCY (%)
vs Load, V
OUT
= 5V, PWM Mode
3130 G03
V
= 2.5V
V
IN
= 3.6V
V
IN
= 5V
V
IN
= 12V
V
IN
= 24V
IN
LOAD CURRENT (mA)
0.01
0.1
1
10
100
1k
0
10
20
30
40
50
60
70
80
90
100
EFFICIENCY (%)
OUT
3130 G04
V
= 2.5V
V
IN
= 3.6V
V
IN
= 5V
V
IN
= 12V
V
IN
= 24V
IN
LOAD CURRENT (mA)
0.01
0.1
1
10
100
1k
0
10
20
30
40
50
60
70
80
90
100
EFFICIENCY (%)
OUT
3130 G05
V
= 2.5V
V
IN
= 3.6V
V
IN
= 5V
V
IN
= 12V
V
IN
= 24V
IN
LOAD CURRENT (mA)
0.01
0.1
1
10
100
1k
0.001
0.01
0.1
1
10
100
1k
POWER LOSS (mW)
OUT
3130 G06
V
= 2.5V
V
IN
= 3.6V
V
IN
= 5V
V
IN
= 12V
V
IN
= 24V
IN
LOAD CURRENT (mA)
0.01
0.1
1
10
100
1k
0
10
20
30
40
50
60
70
80
90
100
EFFICIENCY (%)
OUT
3130 G07
V
= 2.5V
V
IN
= 3.6V
V
IN
= 5V
V
IN
= 12V
V
IN
= 24V
IN
LOAD CURRENT (mA)
0.01
0.1
1
10
100
1k
0.001
0.01
0.1
1
10
100
1k
POWER LOSS (mW)
OUT
3130 G08
V
= 2.5V
V
IN
= 3.6V
V
IN
= 5V
V
IN
= 12V
V
IN
= 24V
IN
LOAD CURRENT (mA)
0.01
0.1
1
10
100
1k
0
10
20
30
40
50
60
70
80
90
100
EFFICIENCY (%)
OUT
3130 G09
V
= 2.5V
V
IN
= 3.6V
V
IN
= 5V
V
IN
= 12V
V
IN
= 24V
IN
LTC3130/LTC3130-1
6
3130f
For more information www.linear.com/LTC3130
TYPICAL PERFORMANCE CHARACTERISTICS
Efficiency, VOUT = 8V,
PWM Mode (LTC3130)
Efficiency, VOUT = 8V, Burst Mode
Operation (LTC3130)
Power Loss , VOUT = 8V, Burst
Mode Operation (LTC3130)
Efficiency, VOUT = 15V
(LTC3130)
Power Loss, VOUT = 15V, Burst
Mode Operation (LTC3130)
Efficiency, VOUT = 24V
(LTC3130)
Power Loss, VOUT = 5V, Burst
Mode Operation (LTC3130-1)
Power Loss, VOUT = 12V, Burst
Mode Operation (LTC3130-1)
Efficiency, VOUT = 12V, Burst
Mode Operation (LTC3130-1)
TA = 25°C, unless otherwise noted.
LOAD CURRENT (mA)
0.01
0.1
1
10
100
1k
0.001
0.01
0.1
1
10
100
1k
POWER LOSS (mW)
V
OUT
= 5V, Burst Mode
3130 G10
V
= 2.5V
V
IN
= 3.6V
V
IN
= 5V
V
IN
= 12V
V
IN
= 24V
IN
LOAD CURRENT (mA)
0.01
0.1
1
10
100
1k
0
10
20
30
40
50
60
70
80
90
100
EFFICIENCY (%)
OUT
3130 G11
V
= 2.5V
V
IN
= 3.6V
V
IN
= 5V
V
IN
= 12V
V
IN
= 24V
IN
LOAD CURRENT (mA)
0.01
0.1
1
10
100
1k
0.01
0.1
1
10
100
1k
POWER LOSS (mW)
OUT
3130 G12
V
= 2.5V
V
IN
= 3.6V
V
IN
= 5V
V
IN
= 12V
V
IN
= 24V
IN
LOAD CURRENT (mA)
0.01
0.1
1
10
100
1k
0
10
20
30
40
50
60
70
80
90
100
EFFICIENCY (%)
OUT
3130 G13
V
= 2.5V
V
IN
= 3.6V
V
IN
= 5V
V
IN
= 12V
V
IN
= 24V
IN
LOAD CURRENT (mA)
0.01
0.1
1
10
100
1k
0
10
20
30
40
50
60
70
80
90
100
EFFICIENCY (%)
V
OUT
= 8V, Burst Mode
3130 G14
V
= 2.5V
V
IN
= 3.6V
V
IN
= 5V
V
IN
= 12V
V
IN
= 24V
IN
LOAD CURRENT (mA)
0.01
0.1
1
10
100
1k
0.01
0.1
1
10
100
1k
POWER LOSS (mW)
V
OUT
= 8V, Burst Mode
3130 G15
V
= 2.5V
V
IN
= 3.6V
V
IN
= 5V
V
IN
= 12V
V
IN
= 24V
IN
LOAD CURRENT (mA)
0.01
0.1
1
10
100
1k
0
10
20
30
40
50
60
70
80
90
100
EFFICIENCY (%)
V
OUT
= 15V
3130 G16
V
IN
= 3.6V
V
= 5V
V
IN
= 12V
V
IN
= 24V
IN
Burst Mode OPERATION: PWM:
V
IN
= 3.6V
V
IN
= 5V
V
IN
= 12V
V
IN
= 24V
LOAD CURRENT (mA)
0.01
0.1
1
10
100
1k
0.1
1
10
100
1k
POWER LOSS (mW)
3130 G17
OUT
V
IN
= 3.6V
V
IN
= 5V
V
IN
= 12V
V
IN
= 24V
LOAD CURRENT (mA)
0.01
0.1
1
10
100
1k
0
10
20
30
40
50
60
70
80
90
100
EFFICIENCY (%)
OUT
3130 G18
V
IN
= 5V
V
= 12V
V
IN
= 24V
IN
Burst Mode OPERATION: PWM:
V
IN
= 5V
V
IN
= 12V
V
IN
= 24V
LTC3130/LTC3130-1
7
3130f
For more information www.linear.com/LTC3130
TYPICAL PERFORMANCE CHARACTERISTICS
Maximum Output Current
vs VIN and VOUT
VIN Shutdown Current vs
VIN (RUN = 0V, EXTVCC = 0V)
VIN UVLO Current
vs VIN (0.85V ≤ RUN ≤ 1.01V,
EXTVCC = 0V)
No-Load Input Current in Burst
Mode Operation vs VIN and VOUT
(LTC3130, MODE = 0V)
TA = 25°C, unless otherwise noted.
No-Load Input Current in Fixed
Frequency vs VIN and VOUT
(MODE = VCC)
No-Load Input Current in Burst
Mode Operation vs VIN and VOUT
(LTC3130-1, MODE = 0V)
Burst Mode Operation, Load
Current Threshold vs VIN and
VOUT (MODE = 0V)
Average Inductor Current Limit
vs MPPC Voltage
LOAD CURRENT (mA)
0.01
0.1
1
10
100
1k
0.1
1
10
100
1k
POWER LOSS (mW)
V
OUT
= 24V, Burst Mode
3130 G19
V
= 5V
V
IN
= 12V
V
IN
= 24V
IN
V
IN
(V)
0
5
10
15
20
25
0
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
V
IN
CURRENT (μA)
CC
3130 G21
VOUT = 1.8V
VOUT = 3.3V
VOUT = 5V
VOUT = 12V
VOUT = 25V
V
IN
(V)
0
5
10
15
20
25
0
5
10
15
20
25
30
I
IN
(mA)
IN
OUT
3130 G25
VOUT = 1.8V
VOUT = 3.3V
VOUT = 5V
VOUT = 12V
VOUT = 25V
V
IN
(V)
0
5
10
15
20
25
0
0.03
0.06
0.09
0.12
0.15
I
OUT
(A)
IN
OUT
3130 G26
MPPC (V)
0.95
0.98
1.01
1.04
1.07
1.10
0
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
INDUCTOR CURRENT LIMIT (A)
vs MPPC Voltage
3130 G27
Power Loss, VOUT = 24V, Burst Mode
Operation (LTC3130)
V
IN
(V)
0
5
10
15
20
25
0
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
1.80
V
IN
CURRENT (μA)
CC
3130 G22
I
OUT
= 2μA (FB DIVIDER)
V
OUT
= 1.8V
V
OUT
= 3.3V
V
OUT
= 5V
V
OUT
= 12V
V
OUT
= 25V
V
IN
(V)
0
5
10
15
20
25
0
5
10
15
20
25
30
I
IN
(μA)
OUT
3130 G23
V
OUT
= 1.8V
V
OUT
= 3.3V
V
OUT
= 5V
V
OUT
=1 2V
V
IN
(V)
0
5
10
15
20
25
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
I
IN
(μA)
and V
OUT
(LTC3130-1, MODE = 0V)
3130 G24
V
OUT
= 1.8V
V
OUT
= 3.3V
V
OUT
= 5V
V
OUT
= 12V
V
OUT
= 25V
V
IN
(V)
0
5
10
15
20
25
0
100
200
300
400
500
600
700
I
OUT
(mA)
IN
OUT
3130 G20
LTC3130/LTC3130-1
8
3130f
For more information www.linear.com/LTC3130
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)
Oscillator Frequency vs
Temperature (Normalized to 25°C)
Oscillator Frequency vs VCC
(Normalized to VCC = 4V)
Switch RDS(ON) vs Temperature
Accurate RUN Threshold vs
Temperature (Normalized to 25°C)
Switch RDS(ON) vs VCC
Fixed Frequency PWM
Waveforms (Buck Region)
TEMPERATURE (
°
C)
–50
–25
0
25
50
75
100
125
150
–10.00
–9.00
–8.00
–7.00
–6.00
–5.00
–4.00
–3.00
–2.00
–1.00
0
CHANGE IN AVERAGE CURRENT LIMIT (%)
(Normalized to 25
C)
3130 G28
TEMPERATURE (
°
C)
–50
–25
0
25
50
75
100
125
150
–1.00
–0.90
–0.80
–0.70
–0.60
–0.50
–0.40
–0.30
–0.20
–0.10
0.00
CHANGE IN FB VOLTAGE (%)
LTC3130 (Normalized to 25
C)
3130 G29
TEMPERATURE (
°
C)
–50
–25
0
25
50
75
100
125
150
–1.00
–0.90
–0.80
–0.70
–0.60
–0.50
–0.40
–0.30
–0.20
–0.10
0.00
CHANGE IN OUTPUT VOLTAGE (%)
LTC3130–1 (Normalized to 25
C)
3130 G30
TEMPERATURE (
°
C)
–50
–25
0
25
50
75
100
125
150
–1.00
–0.90
–0.80
–0.70
–0.60
–0.50
–0.40
–0.30
–0.20
–0.10
0.00
CHANGE IN RUN THRESHOLD (%)
3130 G33
TEMPERATURE (
°
C)
–50
–25
0
25
50
75
100
125
150
0.20
0.25
0.30
0.35
0.40
0.45
0.50
0.55
R
DSON
(Ω)
Switch Rdson vs Temperature
3131 G34
V
CC
(V)
2.5
3
3.5
4
0.30
0.33
0.36
0.39
0.42
0.45
R
DSON
(Ω)
Switch Rdson vs V
CC
3134 G35
SW2
(5V/DIV)
INDUCTOR
CURRENT
(0.5A/DIV)
200nsec/DIV 3130 G36
SW1
(10V/DIV)
TEMPERATURE (
°
C)
–50
–25
0
25
50
75
100
125
150
–10.00
–9.00
–8.00
–7.00
–6.00
–5.00
–4.00
–3.00
–2.00
–1.00
0
CHANGE IN OSCILLATOR FREQUENCY (%)
(Normalized to 25
C)
3130 G31
V
CC
(V)
2.4
2.8
3.2
3.6
4.0
97
98
99
100
NORMALIZED OSCILLATOR FREQUENCY (%)
Oscillator Frequency vs V
CC
3130 G32
LTC3130/LTC3130-1
9
3130f
For more information www.linear.com/LTC3130
Fixed Frequency PWM
Waveforms (Boost Region)
Fixed Frequency Output
Voltage Ripple
TYPICAL PERFORMANCE CHARACTERISTICS
TA = 25°C, unless otherwise noted.
Burst Mode Operation Waveforms
PWM to Burst Mode Operation
Transition
Start-Up Sequence When Raising
RUN Pin (VIN = 12V)
Start-Up Sequence When
Applying VIN (RUN Tied to VIN)
VCC Response to a Step on
EXTVCC (VIN > 4V)
VCC Response to a Step on
EXTVCC (VIN = 3V)
Fixed Frequency PWM
Waveforms (Buck-Boost Region)
SW2
(5V/DIV)
INDUCTOR
CURRENT
(0.5A/DIV)
200nsec/DIV 3130 G37
SW1
(5V/DIV)
SW2
(10V/DIV)
INDUCTOR
CURRENT
(0.5A/DIV)
200nsec/DIV 3130 G38
SW1
(5V/DIV)
VOUT
(50mV/DIV)
INDUCTOR
CURRENT
(0.2A/DIV)
500nsec/DIV 3130 G39
12VIN, 5VOUT,
ILOAD = 0.5A, COUT = 22µF
0
VOUT
(50mV/DIV)
INDUCTOR
CURRENT
(0.2A/DIV)
20μsec/DIV 3130 G40
5VOUT
ILOAD =10mA
COUT = 22µF
VOUT
(100mV/
DIV)
INDUCTOR
CURRENT
(0.2A/DIV)
1msec/DIV 3130 G41
MODE PIN
(2V/DIV)
12VIN, 5VOUT,
ILOAD = 20mA, COUT = 22µF
RUN
(5V/DIV)
INDUCTOR
CURRENT
(0.2A/DIV)
2msec/DIV 3138 G43
VCC
(2V/DIV)
VOUT
(2V/DIV)
VCC
(2V/DIV)
1msec/DIV 3130 G44
EXTVCC
(5V/DIV)
0
0
VCC
(2V/DIV)
EXTVCC
(5V/DIV)
1msec/DIV 3130 G45
0
0
VIN
(10V/DIV)
INDUCTOR
CURRENT
(0.2A/DIV)
2msec/DIV 3130 G42
VCC
(2V/DIV)
VOUT
(2V/DIV)
COUT = 22µF
LTC3130/LTC3130-1
10
3130f
For more information www.linear.com/LTC3130
Step Load Transient Response in
Fixed Frequency
Step Load Transient Response in
Burst Mode Operation
TYPICAL PERFORMANCE CHARACTERISTICS
TA = 25°C, unless otherwise noted.
PGOOD Response to a Drop in
VOUT Due to a Step Overload
VIN Line Step Response in
Fixed Frequency
VIN Line Step Response in
Burst Mode Operation
Output Voltage Short-Circuit
Waveforms
MPPC Response to an Overload
(VMPPC Set to 5V at VIN)
VOUT
(100mV/DIV)
INDUCTOR
CURRENT
(0.5A/DIV)
500μsec/DIV 3130 G46
12VIN, 5VOUT,
50mA to 500mA LOAD STEP
COUT = 22µF, L = 10μH
VOUT
(100mV/DIV)
INDUCTOR
CURRENT
(0.2A/DIV)
1msec/DIV 3130 G47
12VIN, 5VOUT,
10mA to 250mA LOAD STEP
COUT = 22µF, L = 10μH
VOUT
(2V/DIV)
INDUCTOR
CURRENT
(0.5A/DIV)
500μsec/DIV 3130 G48
PGOOD
(2V/DIV)
VOUT
(5V/DIV)
INDUCTOR
CURRENT
(0.2A/DIV)
2msec/DIV 3130 G49
VIN
(5V/DIV)
VOC = 9V
VOUT = 12V
RIN = 20Ω
CIN = 33μF
VOUT
(1V/DIV)
INDUCTOR
CURRENT
(0.2A/DIV) 50μsec/DIV 3130 G50
VIN
(10V/DIV)
5VOUT,
5V TO 25V VIN STEP,
COUT = 22µF, L = 10μH,
LIGHT LOAD
VOUT
(1V/DIV)
INDUCTOR
CURRENT
(0.2A/DIV) 50μsec/DIV 3130 G51
VIN
(10V/DIV)
5VOUT,
5V TO 25V VIN STEP,
COUT = 22µF, L = 10μH,
LIGHT LOAD
VOUT
(2V/DIV)
INDUCTOR
CURRENT
(0.2A/DIV)
10μsec/DIV 3130 G52
LTC3130/LTC3130-1
11
3130f
For more information www.linear.com/LTC3130
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. 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
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
PIN FUNCTIONS
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:
VOUT =1.00V • 1+R1
R2
(Refer 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 induc-
tor 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.
(QFN/MSOP)
LTC3130/LTC3130-1
12
3130f
For more information www.linear.com/LTC3130
PIN FUNCTIONS
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 dynami-
cally 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 switch-
ing 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.
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.
(QFN/MSOP)
LTC3130/LTC3130-1
13
3130f
For more information www.linear.com/LTC3130
LTC3130 BLOCK DIAGRAM
UV
0.7V
FB
PGOOD
3130 BD
VC
1.0V
–7.5%
CLAMP
VCC
PGNDGND ILIM
600mA
200mA
C
VSENSE
VSENSE
VSENSE
VSENSE
D
VCC
DRIVER
OSC
DRIVER
+
–
+
–
+
–
+
–LOGIC
IPK
IZERO
ENABLE
1.2A
+
–
+
–
+
–
50mA
RESET
SLEEP
1.0V
1.05V
0.6V
THERMAL
SHUTDOWN
SOFT-START
B
A
VCC
BSTEXTVCC
VIN
VIN
VCC
RUN
MPPC
MODE
3M
4V
1.0V
VCC_GD
VREF_GD
START
VREF
SW1 SW2 BST2
DRIVER
LDO
VREF
ISENSE
DRIVER
+
–
100mV
+
–
VOUT VOUT
+
–
+
–
+
–
ON
VCC_GD
PVIN
LTC3130/LTC3130-1
14
3130f
For more information www.linear.com/LTC3130
LTC3130-1 BLOCK DIAGRAM
UV
0.7V
PGOOD
31301 BD
VC
FB
1.0V
–7.5%
CLAMP
PGNDGND
600mA
C
VSENSE
VSENSE
VSENSE
VSENSE
D
VCC
DRIVER
OSC
DRIVER
+
–
+
–
+
–
+
–LOGIC
IPK
IZERO
ENABLE
1.2A
+
–
+
–
+
–
50mA
RESET
SLEEP
1.0V
1.05V
0.6V
THERMAL
SHUTDOWN
SOFT-START
B
A
VCC
BSTEXTVCC
VIN
VIN
VCC
RUN
MPPC
MODE
4V
1.0V
VCC_GD
VREF_GD
START
1.0V
SW1 SW2 BST2
DRIVER
LDO
VREF
ISENSE
DRIVER
+
–
100mV
+
–
VOUT VOUT
VOUT
SELECT
INPUTS
VS1
+
–
+
–
+
–
VS2
3M
VCC_GD
ON
PWM
PVIN
LTC3130/LTC3130-1
15
3130f
For more information www.linear.com/LTC3130
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. 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.
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.
A
VCC
BST1
CBST1 CBST2
L
BST2PVIN VOUT
SW1 SW2
VCC
VCC VCC
LTC3130
PGND PGND
3130 F01
B
D
C
Figure 1. Power Stage Schematic
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-
programmed 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 con-
verter 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.
LTC3130/LTC3130-1
16
3130f
For more information www.linear.com/LTC3130
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). Dur-
ing 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 oscilla-
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.
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,
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-
rent 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
OutputCurrent
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 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
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
LTC3130/LTC3130-1
17
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OPERATION
Figure 2. VOUT Feedback Divider (Showing Optional
Feed-Forward Capacitor)
In boost mode, the output current is related to average
inductor current and duty cycle by:
IOUT(BOOST) ≈ IL • VIN
VOUT
• η
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 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
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 Figure2,
according to the equation:
VOUT =1.00V • 1+
R1
R2
(Refer 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 fre-
quency gain. The value isn’t critical, and resistor values of
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 er-
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 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.
3130 F02
LTC3130
VOUT
R1
COUT
FB
GND
CFF
R2
RFF
OPTIONAL
FEED-FORWARD
LTC3130/LTC3130-1
18
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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
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.
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 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.
In automatic Burst Mode operation (MODE pin low), the
IZERO threshold is increased so that reverse inductor cur-
rent does not normally occur. This maximizes efficiency
at light loads.
Note that reverse current is also inhibited during soft-
start(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 Character-
istics section of this data sheet to determine the Burst
Mode transition threshold for various combinations of
VIN andVOUT.
LTC3130/LTC3130-1
19
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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 cur-
rent 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 soft-
started, 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 nomi-
nal 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 start-
up 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.
LTC3130/LTC3130-1
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OPERATION
LTC3130
ENABLE SWITCHING
ENABLE VREF
AND PGOOD
LOGIC THRESHOLD
ACCURATE THRESHOLD
3130 F03
+
–
–
+
0.6V
RUN
1.05V
VIN
R3
R4
Figure 3. Accurate RUN Pin Comparator
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 typi-
cal), 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 estab-
lish 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.
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:
VIN(TURNON) =1.05V • 1+
R3
R4
Once the converter is enabled, the RUN comparator
includes a built-in hysteresis of 100mV, so that the turn-
off threshold will be :
VIN(TURNOFF) =0.95V • 1+
R3
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
LTC3130/LTC3130-1
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OPERATION
Figure 4. MPPC Amplifier with External Resistor Divider
LTC3130
1.0V
VC
CURRENT
COMMAND
VOLTAGE
ERROR AMP
3130 F04
MPPC
FB
R5
R6
RS
VSOURCE
CIN
VIN
VIN
+
–
+
–
+
–
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.
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.
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
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 invert-
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
and regulate VIN to the programmed minimum voltage,
as given by:
VIN(MPPC) =1.00V • 1+
R5
R6
Note that external compensation should not be required
for MPPC loop stability if the input filter capacitor, CIN,
is at least 22µF.
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
function is not required, the MPPC pin should be tied to VCC.
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.
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. 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 provid-
ing 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).
LTC3130/LTC3130-1
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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 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.
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 pos-
sible 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 resis-
tance 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
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 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
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
L
VIN – VOUT
VIN
1
f– tLOW
Amps
∆IL(P-P)(BOOST) =VIN
L
VOUT – VIN
VOUT
1
f– tLOW
Amps
It should be noted that the worst-case peak-to-peak in-
ductor 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.
LTC3130/LTC3130-1
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APPLICATIONS INFORMATION
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
�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 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.
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.
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
VOUT
(V)
LMAX
(μH)
MINIMUM RECOMMENDED OUTPUT CAPACITANCE (μF)
LTC3130-1/LTC3130
WITH FEED FORWARD
LTC3130
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.
LTC3130/LTC3130-1
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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 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
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) =
I
LOAD
t
LOW
COUT
Volts
∆VP-P(BOOST) =ILOAD
fCOUT
VOUT – VIN +tLOWfVIN
VOUT
Volts
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
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
the series resistance of the output capacitor and all other
terms as previously defined:
∆VP-P(BUCK) =
I
LOAD
R
ESR
1– tLOWf≅ILOADRESR Volts
∆VP-P(BOOST) =ILOADRESRVOUT
VIN 1– tLOWf
( )
≅ILOADRESR
VOUT
V
IN
Volts
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.
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 opera-
tion 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.
LTC3130/LTC3130-1
25
3130f
For more information www.linear.com/LTC3130
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 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.
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.
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.
Beware of Capacitor DC Bias Effect
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
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
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.
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 (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 oper-
ate about the programmed optimal voltage for maximum
power transfer.
LTC3130/LTC3130-1
26
3130f
For more information www.linear.com/LTC3130
APPLICATIONS INFORMATION
In these “trickle-charge” applications, a larger input capaci-
tor 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 • VOUT2
ηVIN2– 0.9 • VIN2
( )
( )
( )
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) >
I
OUT
• V
OUT
•2• t
ηVIN2– 0.9 • VIN2
( )
( )
( )
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.
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 inde-
pendent 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
LTC3130/LTC3130-1
27
3130f
For more information www.linear.com/LTC3130
APPLICATIONS INFORMATION
LTC3130/
LTC3130-1
VOUT VOUT
4V TO 25V
PVIN
VIN
RUN
VIN
1V TO 25V
COUT BAT54C
EXTVCC
3031 F05
EXTVCC
SGND 4.7µF 3.6V
+
V
+
–
Figure 5. Using a Battery Just for Start-Up from Low VIN
V
+
–
+
–ENABLE
SWITCHING
1.05V
3130 F06
EXTVCC LTC3130
RUN
2M
1M
VEXT
Figure 6. Using the RUN Pin to Set the Minimum Voltage
for EXTVCC to 3.15V
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.
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.
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
Programming the MPPC Voltage
As discussed in the previous section, the LTC3130/
LTC3130-1 include an MPPC function to optimize perfor-
mance 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:
VIN(MPPC) =1.0V • 1+R5
R6
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% of its open-circuit voltage. For example, when operat-
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
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.
LTC3130/LTC3130-1
28
3130f
For more information www.linear.com/LTC3130
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
Thermal Considerations
The power switches of the LTC3130/LTC3130-1 are de-
signed to operate continuously with currents up to the
internal current limit thresholds. However, when operating
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
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 recom-
mended for these applications.
LTC3130/LTC3130-1
29
3130f
For more information www.linear.com/LTC3130
Figure 7. Typical 2-Layer PC Board Layout (QFN Package Shown)
APPLICATIONS INFORMATION
CBST1 CBST2
RPGD
COUT
CEXT
CVCC
CIN
VIN
GND
LTC3130
L1
R2 R1
RUN
MPPC
ILIM
MODE
PGOOD
VOUT
GND
CBST1 CBST2
RPGD
COUT
CEXT
CVCC
CIN
VIN
GND
LTC3130-1
L1
RUN
MPPC
VS1
VS2
MODE
PGOOD
VOUT
GND
8603 F07
LTC3130/LTC3130-1
30
3130f
For more information www.linear.com/LTC3130
APPLICATIONS INFORMATION
Figure 8. Outdoor Solar Panel Powered, 600mA Supercapacitor Charger Using MPPC
Figure 9. Battery-Powered 24V Converter with 200mA ILIM to Limit Battery Droop
BST1 BST2
PVIN
VIN
VIN
3130 F08
VOUT
RUN
4.99M
VOC = 5V
VOP = 3.5V
2M
MPPC
ILIM
MODE
FBVCC
PGOOD
VCC
4.7µF
4.7µF
47µF
1µF
VOUT
4.4V
EXTVCC
SW1 SW2
GND PGND
22nF22nF 4.7µH
LTC3130
1M
3.4M
100F
100k
100k
PV
PANEL
+
100F
+
TECATE
TPL-100/22x45F
BST1 BST2
PVIN
VIN
3.6V
Li-SOCI2
3130 F09
VOUT
RUN
MPPC
ILIM
MODE
FB
VCC PGOOD PGOOD
VCC
10µF
4.7µF
10µF
VOUT
24V
20mA
EXTVCC
SW1 SW2
GND PGND
22nF22nF 10µH
LTC3130
174k
4.02M
1M 10pF
+200k
VIN
1µF
LTC3130/LTC3130-1
31
3130f
For more information www.linear.com/LTC3130
Figure 10. Wide VIN Range 15V Converter with Burst Mode Operation
Figure 11. Low Noise, Wide VIN Range 5V Converter
APPLICATIONS INFORMATION
BST1 BST2
PVIN
VIN
2.4V TO 25V
3130 F10
VOUT
RUN
MPPC
ILIM
MODE
FB
VCC PGOOD
VCC
10µF 10pF
4.7µF
10µF
VOUT
15V
500mA
(VIN > 15V)
EXTVCC
SW1 SW2
GND PGND
22nF22nF 10µH
LTC3130
357k
4.99M
249k
VIN
1µF
BST1 BST2
PVIN
VCC
3130 F11
VOUT
RUN
MPPC
MODE
VS1
VS2
PGOOD PGOOD
VCC
22µF
4.7µF
1M
10µF
VIN
0.95V TO 25V
(2.4V TO START)
VOUT
5V
500mA
(VIN > 5V)
EXTVCC
SW1 SW2
GND PGND
22nF22nF 6.8µH
LTC3130-1
VIN
1µF
LTC3130/LTC3130-1
32
3130f
For more information www.linear.com/LTC3130
APPLICATIONS INFORMATION
Figure 12. Multiple VIN 5V Out Application, Using the LTC4412 PowerPath™ Controller
Figure 13. 12V Converter Uses MPPC Function to Maintain a Minimum VIN from a Current Limited Source
BST1
MBR0520
12V WALL ADAPTER INPUT
USB 3.0 INPUT BST2
PVIN
VCC
VCC
3130 F12
VOUT
RUN
VIN
CTL
GATE
SENSE
Li-Ion STAT
LTC4412
GND
MPPC
MODE
VS1
VS2
PGOOD PGOOD
VCC
22µF
4.7µF
1M
10µF
VOUT
5V
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
EXTVCC
SW1 SW2
GND PGND
22nF22nF 6.8µH
LTC3130-1
B130
BSS314
+
VIN
1µF
BST1 BST2
PVIN
VCC
3130 F13
VOUT
RUN
698k
VIN
VMPPC = 8V
MPPC
MODE
VS1
VS2
PGOOD
VCC
10µF
22µF
10V
TO
14V
4.7µF
VOUT
12V
100mA MIN
EXTVCC
SW1 SW2
GND PGND
22nF22nF 6.8µH
LTC3130-1
10Ω
100k
+
VIN
1µF
LTC3130/LTC3130-1
33
3130f
For more information www.linear.com/LTC3130
APPLICATIONS INFORMATION
Figure 14. 3.3V Converter with "Last Gasp" Hold-Up, Runs Storage Capacitor Down to 0.9V
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
BST1 BST2
PVIN
VCC
3130 F14
VOUT
RUN
MPPC
MODE
VS1
VS2
PGOOD
VCC
47µF
4.7µF
4.7µF
470µF
25V
×2
DC SOURCE
<0.9V TO 25V
(2.4V + VD1
TO START)
VOUT
3.3V
EXTVCC
SW1 SW2
GND PGND
22nF22nF 6.8µH
LTC3130-1
+
*D1 PREVENTS DISCHARGE OF INPUT CAPACITOR TO
THE SOURCE. MAY NOT BE REQUIRED IN ALL APPLICATIONS.
D1*
VIN
BST1 BST2
VCC
3130 F15
VOUT
RUN
10M
BAS70-05 UVLO THRESHOLDS
11.55V/0.95V
BAS70-06
MPPC
MODE
VS1
VS2
PGOOD
VCC
22µF
4.7µF
47µF
16V
CER
×2
INPUT SOURCES:
RF
AC
PIEZO
COIL-MAGNET
VOUT
5V
EXTVCC
SW1 SW2
GND PGND
22nF22nF 6.8µH
LTC3130-1
1M
PVIN
VIN
*D1 IS REQUIRED WHEN USING THE MSOP PACKAGE.
1µF
LTC3130/LTC3130-1
34
3130f
For more information www.linear.com/LTC3130
TYPICAL APPLICATIONS
Figure 16. 12V Converter with Burst Mode Operation and VIN UVLO
Figure 17. Single-Cell 1.2V, 200mA Buck Boost Converter,
Using the LTC3525-3.3 to Provide the EXTVCC Bias Supply
BST1 BST2
VIN
ALKALINE
OR NiMH
0.85V to 1.5V
3130 F17
VOUT
RUN
MPPC
ILIM
MODE
FB
VCC PGOOD
VCC
47µF
2.2µF 4.7µF
100pF
4.7µF
10µF
VOUT2
1.2V
EXTVCC
SW1 SW2
GND PGND
22nF
VOUT1
3.3V
22nF 1.5µH
10µH
SW
GND
LTC3525-3.3
VIN
SHDN
VOUT
LTC3130
2M
402k
+20k
PVIN
VIN
1µF
BST1 BST2
VCC
3130 F16
VIN
4 Li-Ion
VOUT
RUN
MPPC
MODE
VS1
PGOOD
VCC
10µF
4.7µF
10µF
4.99M
UVLO = 11.41V VOUT
12V
500mA
EXTVCC
SW1 SW2
GND PGND
22nF22nF 6.8µH
LTC3130-1
453k
PVIN
VIN
+
*D1 IS REQUIRED WHEN USING THE MSOP PACKAGE.
LTC3130/LTC3130-1
35
3130f
For more information www.linear.com/LTC3130
TYPICAL APPLICATIONS
Figure 18. Wide VIN Range, Low Noise 1.8V Converter Uses Charge Pump to Generate an EXTVCC Supply
Figure 19. Wide VIN Range 3.6V Converter with Tw o Programmed Current Limit Levels
BST1 BST2
VCC
3130 F18
VOUT
RUN
MPPC
MODE
VS1
VS2
PGOOD
VCC
47µF
4.7µF
10µF
VIN
<0.9V TO 25V
(2.4V TO START)
VOUT
1.80V
EXTVCC
SW1 SW2
GND PGND
22nF
1μF BAT54S
22nF 3.3µH
LTC3130-1
PVIN
VIN
1µF
4.7µF
BST1 BST2
VIN
0.95V TO 25V
(2.4V TO START)
3130 F19
VOUT
RUN
MPPC
ILIM
MODE
FB
VCC PGOOD
VCC
47µF 15pF
4.7µF
10µF
VOUT
3.6V
EXTVCC
SW1 SW2
GND PGND
22nF22nF 6.8µH
LTC3130
1M
2.61M
200mA 600mA
100k
PVIN
VIN
1µF
LTC3130/LTC3130-1
36
3130f
For more information www.linear.com/LTC3130
PACKAGE DESCRIPTION
Please refer to http://www.linear.com/product/LTC3130#packaging for the most recent package drawings.
3.00 ±0.10 1.50 REF
4.00 ±0.10
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
PIN 1
TOP MARK
(NOTE 6)
0.40 ±0.10
19 20
1
2
BOTTOM VIEW—EXPOSED PAD
2.50 REF
0.75 ±0.05
R = 0.115
TYP
PIN 1 NOTCH
R = 0.20 OR 0.25
× 45° CHAMFER
0.25 ±0.05
0.50 BSC
0.200 REF
0.00 – 0.05
(UDC20) QFN 1106 REV Ø
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED
0.70 ±0.05
0.25 ±0.05
2.50 REF
3.10 ±0.05
4.50 ±0.05
1.50 REF
2.10 ±0.05
3.50 ±0.05
PACKAGE OUTLINE
R = 0.05 TYP
1.65 ±0.10
2.65 ±0.10
1.65 ±0.05
2.65 ±0.05
0.50 BSC
UDC Package
20-Lead Plastic QFN (3mm × 4mm)
(Reference LTC DWG # 05-08-1742 Rev Ø)
LTC3130/LTC3130-1
37
3130f
For more information www.linear.com/LTC3130
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-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
PACKAGE DESCRIPTION
Please refer to http://www.linear.com/product/LTC3130#packaging for the most recent package drawings.
MSOP (MSE16) 0213 REV F
0.53 ±0.152
(.021 ±.006)
SEATING
PLANE
0.18
(.007)
1.10
(.043)
MAX
0.17 –0.27
(.007 – .011)
TYP
0.86
(.034)
REF
0.50
(.0197)
BSC
16
16151413121110
12345678
9
9
18
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.
0.254
(.010) 0° – 6° TYP
DETAIL “A”
DETAIL “A”
GAUGE PLANE
5.10
(.201)
MIN
3.20 – 3.45
(.126 – .136)
0.889 ±0.127
(.035 ±.005)
RECOMMENDED SOLDER PAD LAYOUT
0.305 ±0.038
(.0120 ±.0015)
TYP
0.50
(.0197)
BSC
BOTTOM VIEW OF
EXPOSED PAD OPTION
2.845 ±0.102
(.112 ±.004)
2.845 ±0.102
(.112 ±.004)
4.039 ±0.102
(.159 ±.004)
(NOTE 3)
1.651 ±0.102
(.065 ±.004)
1.651 ±0.102
(.065 ±.004)
0.1016 ±0.0508
(.004 ±.002)
3.00 ±0.102
(.118 ±.004)
(NOTE 4)
0.280 ±0.076
(.011 ±.003)
REF
4.90 ±0.152
(.193 ±.006)
DETAIL “B”
DETAIL “B”
CORNER TAIL IS PART OF
THE LEADFRAME FEATURE.
FOR REFERENCE ONLY
NO MEASUREMENT PURPOSE
0.12 REF
0.35
REF
MSE Package
16-Lead Plastic MSOP, Exposed Die Pad
(Reference LTC DWG # 05-08-1667 Rev F)
LTC3130/LTC3130-1
38
3130f
For more information www.linear.com/LTC3130
LINEAR TECHNOLOGY CORPORATION 2016
LT 0816 • PRINTED IN USA
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com/LTC3130
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PART DESCRIPTION
VIN
RANGE (V)
VOUT
RANGE (V) IQ(μA) PACKAGE
LTC3129/LTC3129-1 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
BST1 BST2
VCC
VCC
3130 TA02
VOUT
RUN
MPPC
MODE
VS1
VS2
PGOOD
VCC
22µF BAT54C
4.7µF
4.7µF
10µF 3.6V
TADIRAN TL-4902
VIN
0.95V TO 25V
VOUT
5V
EXTVCC
SW1 SW2
GND PGND
22nF22nF 6.8µH
LTC3130-1
STOP RUN
+
PVIN
VIN
1µF
