POWER LOSS (W)
LTC3122
15V, 2.5A Synchronous
Step-Up DC/DC Converter
with Output Disconnect
Fea T Descrip T
?
n
V Range: 1.8V to 5.5V, 500mV After Start-Up The LTC 3122 is a synchronous step-up DC/DC converter
IN
n
Output Voltage Range: 2.2V to 15V with true output disconnect and inrush current limiting. The
n
800mA Output Current for V = 5V and V = 12V 2.5A current limit along with the ability to program output
IN OUT
n
Output Disconnects from Input When Shut Down voltages up to 15V makes the LTC3122 well suited for a
n
Synchronous Rectification: Up to 95% Efficiency variety of demanding applications. Once started, opera-
n
Inrush Current Limit tion will continue with inputs down to 500mV, extending
n
Up to 3MHz Adjustable Switching Frequency runtime in many applications.
Synchronizable to External Clock
The LTC3122 features output disconnect in shutdown,
?
n
Selectable Burst Mode Operation: 25?A I
Q
dramatically reducing input power drain and enabling
n
Output Overvoltage Protection
V to completely discharge. Adjustable PWM switching
OUT
n
Soft-Start
from 100kHz to 3MHz optimizes applications for highest
n
<1?A I in Shutdown
Q
efficiency or smallest solution footprint. The oscillator
n
12-Lead, 3mm ? 4mm ? 0.75mm Thermally
can also be synchronized to an external clock for noise
Enhanced DFN and MSOP Packages
sensitive applications. Selectable Burst Mode operation
reduces quiescent current to 25?A, ensuring high efficiency
a T
across the entire load range. An internal soft-start limits
inrush current during start-up.
n
RF Power
n
Piezo Actuators
Other features include a <1?A shutdown current and ro-
n
Small DC Motors
bust protection under short-circuit, thermal overload, and
n
12V Analog Rail From Battery, 5V, or Backup Capacitor
output overvoltage conditions. The LTC3122 is offered in
both a low profile 12-lead (3mm ? 4mm ? 0.75 mm) DFN
L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks
and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the
package and a 12-lead thermally enhanced MSOP package.
property of their respective owners.
Typical a T
5V to 12V Synchronous Boost Converter with Output Disconnect Efficiency Curve
100 10
3.3?H
V
IN
Burst Mode
5V 90
OPERATION
SW 80
V
OUT
V V
12V
IN OUT
70
1
800mA
LTC3122
PWM
SD
OFF ON 100nF 60
4.7?F
BURST PWM PWM/SYNC CAP 50
1.02M
40
RT FB
22?F
0.1
30
PWM POWER LOSS
V V
113k
CC C
20
SGND PGND 210k
57.6k
10
10pF
4.7?F 390pF
0 0.01
0.01 0.1 1 10 100 1000
LOAD CURRENT (mA)
3122 TA01b
3122 TA01a
3122fa
1
For more information www.linear.com/LTC3122
EFFICIENCY (%)
ion pplica
ions pplica
ion uresPOWER LOSS (W)
LTC3122
15V, 2.5A Synchronous
Step-Up DC/DC Converter
with Output Disconnect
Fea T Descrip T
?
n
V Range: 1.8V to 5.5V, 500mV After Start-Up The LTC 3122 is a synchronous step-up DC/DC converter
IN
n
Output Voltage Range: 2.2V to 15V with true output disconnect and inrush current limiting. The
n
800mA Output Current for V = 5V and V = 12V 2.5A current limit along with the ability to program output
IN OUT
n
Output Disconnects from Input When Shut Down voltages up to 15V makes the LTC3122 well suited for a
n
Synchronous Rectification: Up to 95% Efficiency variety of demanding applications. Once started, opera-
n
Inrush Current Limit tion will continue with inputs down to 500mV, extending
n
Up to 3MHz Adjustable Switching Frequency runtime in many applications.
Synchronizable to External Clock
The LTC3122 features output disconnect in shutdown,
?
n
Selectable Burst Mode Operation: 25?A I
Q
dramatically reducing input power drain and enabling
n
Output Overvoltage Protection
V to completely discharge. Adjustable PWM switching
OUT
n
Soft-Start
from 100kHz to 3MHz optimizes applications for highest
n
<1?A I in Shutdown
Q
efficiency or smallest solution footprint. The oscillator
n
12-Lead, 3mm ? 4mm ? 0.75mm Thermally
can also be synchronized to an external clock for noise
Enhanced DFN and MSOP Packages
sensitive applications. Selectable Burst Mode operation
reduces quiescent current to 25?A, ensuring high efficiency
a T
across the entire load range. An internal soft-start limits
inrush current during start-up.
n
RF Power
n
Piezo Actuators
Other features include a <1?A shutdown current and ro-
n
Small DC Motors
bust protection under short-circuit, thermal overload, and
n
12V Analog Rail From Battery, 5V, or Backup Capacitor
output overvoltage conditions. The LTC3122 is offered in
both a low profile 12-lead (3mm ? 4mm ? 0.75 mm) DFN
L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks
and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the
package and a 12-lead thermally enhanced MSOP package.
property of their respective owners.
Typical a T
5V to 12V Synchronous Boost Converter with Output Disconnect Efficiency Curve
100 10
3.3?H
V
IN
Burst Mode
5V 90
OPERATION
SW 80
V
OUT
V V
12V
IN OUT
70
1
800mA
LTC3122
PWM
SD
OFF ON 100nF 60
4.7?F
BURST PWM PWM/SYNC CAP 50
1.02M
40
RT FB
22?F
0.1
30
PWM POWER LOSS
V V
113k
CC C
20
SGND PGND 210k
57.6k
10
10pF
4.7?F 390pF
0 0.01
0.01 0.1 1 10 100 1000
LOAD CURRENT (mA)
3122 TA01b
3122 TA01a
3122fa
1
For more information www.linear.com/LTC3122
EFFICIENCY (%)
ion pplica
ions pplica
ion uresLTC3122
a Te Maxi Mu M r a T
(Note 1)
V Voltage .................................................. ?0.3V to 6V All Other Pins ............................................... ?0.3V to 6V
IN
V Voltage ............................................ ?0.3V to 18V Operating Junction Temperature Range (Notes 3, 4)
OUT
SW Voltage (Note 2) .................................. ?0.3V to 18V LTC3122E/LTC3122I .......................... ?40?C to 125?C
SW Voltage (Pulsed < 100ns) (Note 2) ....... ?0.3V to 19V LTC3122H .......................................... ?40?C to 150?C
V , RT Voltage .......................................... ?0.3V to V Storage Temperature Range .................. ?65?C to 150?C
C CC
CAP Voltage MSE Lead Temperature (Soldering, 10sec) ...........300?C
V < 5.7V ............................?0.3V to (V + 0.3V)
OUT OUT
5.7V ? V ? 11.7V...... (V ? 6V) to (V + 0.3V)
OUT OUT OUT
V > 11.7V .................................(V ? 6V) to 12V
OUT OUT
p in c F T
TOP VIEW
TOP VIEW
SW 1 12 CAP
SW 1 12 CAP
PGND 2 11 V
OUT
PGND 2 11 V
OUT
V 3 10 SGND
IN
13 V 3 13 10 SGND
IN
PGND PGND
PWM/SYNC 4 9 SD
PWM/SYNC 4 9 SD
5
V 8 FB
CC
V 5 8 FB
CC RT 6 7 V
C
RT 6 7 V
C
MSE PACKAGE
12-LEAD PLASTIC MSOP
DE PACKAGE
T = 150?C, ? = 40?C/W (NOTE 5), ? = 10?C/W
JMAX JA JC
12-LEAD (4mm ? 3mm) PLASTIC DFN
EXPOSED PAD (PIN 13) IS PGND,
T = 125?C, ? = 43?C/W (NOTE 5), ? = 5?C/W
JMAX JA JC
MUST BE SOLDERED TO PCB FOR RATED THERMAL PERFORMANCE
EXPOSED PAD (PIN 13) IS PGND,
MUST BE SOLDERED TO PCB FOR RATED THERMAL PERFORMANCE
o r Der i n F Ma T
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC3122EDE#PBF LTC3122EDE#TRPBF 3122 12-Lead (4mm ? 3mm) Plastic DFN ?40?C to 125?C
LTC3122IDE#PBF LTC3122IDE#TRPBF 3122 12-Lead (4mm ? 3mm) Plastic DFN ?40?C to 125?C
LTC3122EMSE#PBF LTC3122EMSE#TRPBF 3122 12-Lead Plastic MSOP ?40?C to 125?C
LTC3122IMSE#PBF LTC3122IMSE#TRPBF 3122 12-Lead Plastic MSOP ?40?C to 125?C
LTC3122HMSE#PBF LTC3122HMSE#TRPBF 3122 12-Lead Plastic MSOP ?40?C to 150?C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Consult LTC Marketing for information on non-standard lead based finish parts.
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/
3122fa
2
For more information www.linear.com/LTC3122
ion or
ion igura on
ings bsoluPOWER LOSS (W)
LTC3122
15V, 2.5A Synchronous
Step-Up DC/DC Converter
with Output Disconnect
Fea T Descrip T
?
n
V Range: 1.8V to 5.5V, 500mV After Start-Up The LTC 3122 is a synchronous step-up DC/DC converter
IN
n
Output Voltage Range: 2.2V to 15V with true output disconnect and inrush current limiting. The
n
800mA Output Current for V = 5V and V = 12V 2.5A current limit along with the ability to program output
IN OUT
n
Output Disconnects from Input When Shut Down voltages up to 15V makes the LTC3122 well suited for a
n
Synchronous Rectification: Up to 95% Efficiency variety of demanding applications. Once started, opera-
n
Inrush Current Limit tion will continue with inputs down to 500mV, extending
n
Up to 3MHz Adjustable Switching Frequency runtime in many applications.
Synchronizable to External Clock
The LTC3122 features output disconnect in shutdown,
?
n
Selectable Burst Mode Operation: 25?A I
Q
dramatically reducing input power drain and enabling
n
Output Overvoltage Protection
V to completely discharge. Adjustable PWM switching
OUT
n
Soft-Start
from 100kHz to 3MHz optimizes applications for highest
n
<1?A I in Shutdown
Q
efficiency or smallest solution footprint. The oscillator
n
12-Lead, 3mm ? 4mm ? 0.75mm Thermally
can also be synchronized to an external clock for noise
Enhanced DFN and MSOP Packages
sensitive applications. Selectable Burst Mode operation
reduces quiescent current to 25?A, ensuring high efficiency
a T
across the entire load range. An internal soft-start limits
inrush current during start-up.
n
RF Power
n
Piezo Actuators
Other features include a <1?A shutdown current and ro-
n
Small DC Motors
bust protection under short-circuit, thermal overload, and
n
12V Analog Rail From Battery, 5V, or Backup Capacitor
output overvoltage conditions. The LTC3122 is offered in
both a low profile 12-lead (3mm ? 4mm ? 0.75 mm) DFN
L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks
and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the
package and a 12-lead thermally enhanced MSOP package.
property of their respective owners.
Typical a T
5V to 12V Synchronous Boost Converter with Output Disconnect Efficiency Curve
100 10
3.3?H
V
IN
Burst Mode
5V 90
OPERATION
SW 80
V
OUT
V V
12V
IN OUT
70
1
800mA
LTC3122
PWM
SD
OFF ON 100nF 60
4.7?F
BURST PWM PWM/SYNC CAP 50
1.02M
40
RT FB
22?F
0.1
30
PWM POWER LOSS
V V
113k
CC C
20
SGND PGND 210k
57.6k
10
10pF
4.7?F 390pF
0 0.01
0.01 0.1 1 10 100 1000
LOAD CURRENT (mA)
3122 TA01b
3122 TA01a
3122fa
1
For more information www.linear.com/LTC3122
EFFICIENCY (%)
ion pplica
ions pplica
ion uresPOWER LOSS (W)
LTC3122
15V, 2.5A Synchronous
Step-Up DC/DC Converter
with Output Disconnect
Fea T Descrip T
?
n
V Range: 1.8V to 5.5V, 500mV After Start-Up The LTC 3122 is a synchronous step-up DC/DC converter
IN
n
Output Voltage Range: 2.2V to 15V with true output disconnect and inrush current limiting. The
n
800mA Output Current for V = 5V and V = 12V 2.5A current limit along with the ability to program output
IN OUT
n
Output Disconnects from Input When Shut Down voltages up to 15V makes the LTC3122 well suited for a
n
Synchronous Rectification: Up to 95% Efficiency variety of demanding applications. Once started, opera-
n
Inrush Current Limit tion will continue with inputs down to 500mV, extending
n
Up to 3MHz Adjustable Switching Frequency runtime in many applications.
Synchronizable to External Clock
The LTC3122 features output disconnect in shutdown,
?
n
Selectable Burst Mode Operation: 25?A I
Q
dramatically reducing input power drain and enabling
n
Output Overvoltage Protection
V to completely discharge. Adjustable PWM switching
OUT
n
Soft-Start
from 100kHz to 3MHz optimizes applications for highest
n
<1?A I in Shutdown
Q
efficiency or smallest solution footprint. The oscillator
n
12-Lead, 3mm ? 4mm ? 0.75mm Thermally
can also be synchronized to an external clock for noise
Enhanced DFN and MSOP Packages
sensitive applications. Selectable Burst Mode operation
reduces quiescent current to 25?A, ensuring high efficiency
a T
across the entire load range. An internal soft-start limits
inrush current during start-up.
n
RF Power
n
Piezo Actuators
Other features include a <1?A shutdown current and ro-
n
Small DC Motors
bust protection under short-circuit, thermal overload, and
n
12V Analog Rail From Battery, 5V, or Backup Capacitor
output overvoltage conditions. The LTC3122 is offered in
both a low profile 12-lead (3mm ? 4mm ? 0.75 mm) DFN
L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks
and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the
package and a 12-lead thermally enhanced MSOP package.
property of their respective owners.
Typical a T
5V to 12V Synchronous Boost Converter with Output Disconnect Efficiency Curve
100 10
3.3?H
V
IN
Burst Mode
5V 90
OPERATION
SW 80
V
OUT
V V
12V
IN OUT
70
1
800mA
LTC3122
PWM
SD
OFF ON 100nF 60
4.7?F
BURST PWM PWM/SYNC CAP 50
1.02M
40
RT FB
22?F
0.1
30
PWM POWER LOSS
V V
113k
CC C
20
SGND PGND 210k
57.6k
10
10pF
4.7?F 390pF
0 0.01
0.01 0.1 1 10 100 1000
LOAD CURRENT (mA)
3122 TA01b
3122 TA01a
3122fa
1
For more information www.linear.com/LTC3122
EFFICIENCY (%)
ion pplica
ions pplica
ion uresLTC3122
a Te Maxi Mu M r a T
(Note 1)
V Voltage .................................................. ?0.3V to 6V All Other Pins ............................................... ?0.3V to 6V
IN
V Voltage ............................................ ?0.3V to 18V Operating Junction Temperature Range (Notes 3, 4)
OUT
SW Voltage (Note 2) .................................. ?0.3V to 18V LTC3122E/LTC3122I .......................... ?40?C to 125?C
SW Voltage (Pulsed < 100ns) (Note 2) ....... ?0.3V to 19V LTC3122H .......................................... ?40?C to 150?C
V , RT Voltage .......................................... ?0.3V to V Storage Temperature Range .................. ?65?C to 150?C
C CC
CAP Voltage MSE Lead Temperature (Soldering, 10sec) ...........300?C
V < 5.7V ............................?0.3V to (V + 0.3V)
OUT OUT
5.7V = V = 11.7V...... (V ? 6V) to (V + 0.3V)
OUT OUT OUT
V > 11.7V .................................(V ? 6V) to 12V
OUT OUT
p in c F T
TOP VIEW
TOP VIEW
SW 1 12 CAP
SW 1 12 CAP
PGND 2 11 V
OUT
PGND 2 11 V
OUT
V 3 10 SGND
IN
13 V 3 13 10 SGND
IN
PGND PGND
PWM/SYNC 4 9 SD
PWM/SYNC 4 9 SD
5
V 8 FB
CC
V 5 8 FB
CC RT 6 7 V
C
RT 6 7 V
C
MSE PACKAGE
12-LEAD PLASTIC MSOP
DE PACKAGE
T = 150?C, ? = 40?C/W (NOTE 5), ? = 10?C/W
JMAX JA JC
12-LEAD (4mm ? 3mm) PLASTIC DFN
EXPOSED PAD (PIN 13) IS PGND,
T = 125?C, ? = 43?C/W (NOTE 5), ? = 5?C/W
JMAX JA JC
MUST BE SOLDERED TO PCB FOR RATED THERMAL PERFORMANCE
EXPOSED PAD (PIN 13) IS PGND,
MUST BE SOLDERED TO PCB FOR RATED THERMAL PERFORMANCE
o r Der i n F Ma T
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC3122EDE#PBF LTC3122EDE#TRPBF 3122 12-Lead (4mm ? 3mm) Plastic DFN ?40?C to 125?C
LTC3122IDE#PBF LTC3122IDE#TRPBF 3122 12-Lead (4mm ? 3mm) Plastic DFN ?40?C to 125?C
LTC3122EMSE#PBF LTC3122EMSE#TRPBF 3122 12-Lead Plastic MSOP ?40?C to 125?C
LTC3122IMSE#PBF LTC3122IMSE#TRPBF 3122 12-Lead Plastic MSOP ?40?C to 125?C
LTC3122HMSE#PBF LTC3122HMSE#TRPBF 3122 12-Lead Plastic MSOP ?40?C to 150?C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Consult LTC Marketing for information on non-standard lead based finish parts.
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/
3122fa
2
For more information www.linear.com/LTC3122
ion or
ion igura on
ings bsoluLTC3122
e Trical c T TThe l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T = 25?C (Note 3). V = 3.6V, V = 12V, RT = 57.6k unless otherwise noted.
A IN OUT
PARAMETER CONDITIONS MIN. TYP MAX UNITS
Minimum Start-Up Voltage V = 0V l 1.7 1.8 V
OUT
l
Input Voltage Range After V ? 2.2V 0.5 5.5 V
OUT
Output Voltage Adjust Range l 2.2 15 V
l
Feedback Voltage 1.178 1.202 1.225 V
Feedback Input Current V = 1.4V 1 50 nA
FB
Quiescent Current, Shutdown V = 0V, V = 0V, Not Including Switch Leakage 0.01 1 ?A
SD OUT
Quiescent Current, Active V = 0V, Measured On V , Non-Switching 500 700 ?A
C IN
Quiescent Current, Burst Measured on V , V > 1.4V 25 40 ?A
IN FB
Measured on V , V > 1.4V 10 20 ?A
OUT FB
l
N-channel MOSFET Switch Leakage Current V = 15V, V = 15V, V = 0V 0.1 30 ?A
SW OUT C
P-channel MOSFET Switch Leakage Current V = 0V, V = 15V, V = 0V l 0.1 70 ?A
SW OUT SD
N-channel MOSFET Switch On-Resistance 0.121 ?
P-channel MOSFET Switch On-Resistance 0.188 ?
N-channel MOSFET Current Limit l 2.5 3.5 4.5 A
l
Maximum Duty Cycle V = 1.0V 90 94 %
FB
Minimum Duty Cycle V = 1.4V l 0 %
FB
l
Switching Frequency 0.85 1 1.15 MHz
SYNC Frequency Range l 0.1 3 MHz
l
PWM/SYNC Input High 0.9 ?V V
CC
PWM/SYNC Input Low l 0.1?V V
CC
PWM/SYNC Input Current V = 5.5V 0.01 1 ?A
PWM/SYNC
CAP Clamp Voltage V > 6.1V, Referenced to V ?5.2 ?5.6 ?6.0 V
OUT OUT
V Regulation Voltage V < 2.8V, V > 5V 4 4.25 4.5 V
CC IN OUT
Error Amplifier Transconductance l 70 95 120 ?S
Error Amplifier Output Current ?25 ?A
Soft-Start Time 10 ms
SD Input High l 1.6 V
l
SD Input Low 0.25 V
SD Input Current V = 5.5V 1 2 ?A
SD
Note 1: Stresses beyond those listed under Absolute Maximum Ratings temperature range. The LTC3122H is guaranteed to meet specifications
may cause permanent damage to the device. Exposure to any Absolute over the full ?40?C to 150?C operating junction range. The junction
Maximum Rating condition for extended periods may affect device temperature (T in ?C) is calculated from the ambient temperature (T in
J A
reliability and lifetime. ?C) and power dissipation (P in Watts) according to the formula: T = T
D J A
+ (P ? ? ) where ? is the thermal impedance of the package.
Note 2: Voltage transients on the SW pin beyond the DC limit specified in D JA JA
the Absolute Maximum Ratings are non-disruptive to normal operations Note 4: The LTC3122 includes overtemperature protection that is intended
when using good layout practices, as shown on the demo board or to protect the device during momentary overload conditions. Junction
described in the data sheet or application notes. temperature will exceed 150?C when overtemperature shutdown is active.
Continuous operation above the specified maximum operating junction
Note 3: The LTC3122 is tested under pulsed load conditions such that
temperature may result in device degradation or failure.
T ? T . The LTC3122E is guaranteed to meet performance specifications
A J
from 0?C to 85?C. Specifications over the ?40?C to 125?C operating Note 5: Failure to solder the exposed backside of the package to the PC
junction temperature range are assured by design, characterization and board ground plane will result in a thermal impedance much higher than
correlation with statistical process controls. The LTC3122I is guaranteed the rated package specifications.
to meet specifications over the full ?40?C to 125?C operating junction
3122fa
3
For more information www.linear.com/LTC3122
ics eris harac lecPOWER LOSS (W)
LTC3122
15V, 2.5A Synchronous
Step-Up DC/DC Converter
with Output Disconnect
Fea T Descrip T
?
n
V Range: 1.8V to 5.5V, 500mV After Start-Up The LTC 3122 is a synchronous step-up DC/DC converter
IN
n
Output Voltage Range: 2.2V to 15V with true output disconnect and inrush current limiting. The
n
800mA Output Current for V = 5V and V = 12V 2.5A current limit along with the ability to program output
IN OUT
n
Output Disconnects from Input When Shut Down voltages up to 15V makes the LTC3122 well suited for a
n
Synchronous Rectification: Up to 95% Efficiency variety of demanding applications. Once started, opera-
n
Inrush Current Limit tion will continue with inputs down to 500mV, extending
n
Up to 3MHz Adjustable Switching Frequency runtime in many applications.
Synchronizable to External Clock
The LTC3122 features output disconnect in shutdown,
?
n
Selectable Burst Mode Operation: 25?A I
Q
dramatically reducing input power drain and enabling
n
Output Overvoltage Protection
V to completely discharge. Adjustable PWM switching
OUT
n
Soft-Start
from 100kHz to 3MHz optimizes applications for highest
n
<1?A I in Shutdown
Q
efficiency or smallest solution footprint. The oscillator
n
12-Lead, 3mm ? 4mm ? 0.75mm Thermally
can also be synchronized to an external clock for noise
Enhanced DFN and MSOP Packages
sensitive applications. Selectable Burst Mode operation
reduces quiescent current to 25?A, ensuring high efficiency
a T
across the entire load range. An internal soft-start limits
inrush current during start-up.
n
RF Power
n
Piezo Actuators
Other features include a <1?A shutdown current and ro-
n
Small DC Motors
bust protection under short-circuit, thermal overload, and
n
12V Analog Rail From Battery, 5V, or Backup Capacitor
output overvoltage conditions. The LTC3122 is offered in
both a low profile 12-lead (3mm ? 4mm ? 0.75 mm) DFN
L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks
and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the
package and a 12-lead thermally enhanced MSOP package.
property of their respective owners.
Typical a T
5V to 12V Synchronous Boost Converter with Output Disconnect Efficiency Curve
100 10
3.3?H
V
IN
Burst Mode
5V 90
OPERATION
SW 80
V
OUT
V V
12V
IN OUT
70
1
800mA
LTC3122
PWM
SD
OFF ON 100nF 60
4.7?F
BURST PWM PWM/SYNC CAP 50
1.02M
40
RT FB
22?F
0.1
30
PWM POWER LOSS
V V
113k
CC C
20
SGND PGND 210k
57.6k
10
10pF
4.7?F 390pF
0 0.01
0.01 0.1 1 10 100 1000
LOAD CURRENT (mA)
3122 TA01b
3122 TA01a
3122fa
1
For more information www.linear.com/LTC3122
EFFICIENCY (%)
ion pplica
ions pplica
ion uresPOWER LOSS (W)
LTC3122
15V, 2.5A Synchronous
Step-Up DC/DC Converter
with Output Disconnect
Fea T Descrip T
?
n
V Range: 1.8V to 5.5V, 500mV After Start-Up The LTC 3122 is a synchronous step-up DC/DC converter
IN
n
Output Voltage Range: 2.2V to 15V with true output disconnect and inrush current limiting. The
n
800mA Output Current for V = 5V and V = 12V 2.5A current limit along with the ability to program output
IN OUT
n
Output Disconnects from Input When Shut Down voltages up to 15V makes the LTC3122 well suited for a
n
Synchronous Rectification: Up to 95% Efficiency variety of demanding applications. Once started, opera-
n
Inrush Current Limit tion will continue with inputs down to 500mV, extending
n
Up to 3MHz Adjustable Switching Frequency runtime in many applications.
Synchronizable to External Clock
The LTC3122 features output disconnect in shutdown,
?
n
Selectable Burst Mode Operation: 25?A I
Q
dramatically reducing input power drain and enabling
n
Output Overvoltage Protection
V to completely discharge. Adjustable PWM switching
OUT
n
Soft-Start
from 100kHz to 3MHz optimizes applications for highest
n
<1?A I in Shutdown
Q
efficiency or smallest solution footprint. The oscillator
n
12-Lead, 3mm ? 4mm ? 0.75mm Thermally
can also be synchronized to an external clock for noise
Enhanced DFN and MSOP Packages
sensitive applications. Selectable Burst Mode operation
reduces quiescent current to 25?A, ensuring high efficiency
a T
across the entire load range. An internal soft-start limits
inrush current during start-up.
n
RF Power
n
Piezo Actuators
Other features include a <1?A shutdown current and ro-
n
Small DC Motors
bust protection under short-circuit, thermal overload, and
n
12V Analog Rail From Battery, 5V, or Backup Capacitor
output overvoltage conditions. The LTC3122 is offered in
both a low profile 12-lead (3mm ? 4mm ? 0.75 mm) DFN
L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks
and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the
package and a 12-lead thermally enhanced MSOP package.
property of their respective owners.
Typical a T
5V to 12V Synchronous Boost Converter with Output Disconnect Efficiency Curve
100 10
3.3?H
V
IN
Burst Mode
5V 90
OPERATION
SW 80
V
OUT
V V
12V
IN OUT
70
1
800mA
LTC3122
PWM
SD
OFF ON 100nF 60
4.7?F
BURST PWM PWM/SYNC CAP 50
1.02M
40
RT FB
22?F
0.1
30
PWM POWER LOSS
V V
113k
CC C
20
SGND PGND 210k
57.6k
10
10pF
4.7?F 390pF
0 0.01
0.01 0.1 1 10 100 1000
LOAD CURRENT (mA)
3122 TA01b
3122 TA01a
3122fa
1
For more information www.linear.com/LTC3122
EFFICIENCY (%)
ion pplica
ions pplica
ion uresLTC3122
a Te Maxi Mu M r a T
(Note 1)
V Voltage .................................................. ?0.3V to 6V All Other Pins ............................................... ?0.3V to 6V
IN
V Voltage ............................................ ?0.3V to 18V Operating Junction Temperature Range (Notes 3, 4)
OUT
SW Voltage (Note 2) .................................. ?0.3V to 18V LTC3122E/LTC3122I .......................... ?40?C to 125?C
SW Voltage (Pulsed < 100ns) (Note 2) ....... ?0.3V to 19V LTC3122H .......................................... ?40?C to 150?C
V , RT Voltage .......................................... ?0.3V to V Storage Temperature Range .................. ?65?C to 150?C
C CC
CAP Voltage MSE Lead Temperature (Soldering, 10sec) ...........300?C
V < 5.7V ............................?0.3V to (V + 0.3V)
OUT OUT
5.7V = V = 11.7V...... (V ? 6V) to (V + 0.3V)
OUT OUT OUT
V > 11.7V .................................(V ? 6V) to 12V
OUT OUT
p in c F T
TOP VIEW
TOP VIEW
SW 1 12 CAP
SW 1 12 CAP
PGND 2 11 V
OUT
PGND 2 11 V
OUT
V 3 10 SGND
IN
13 V 3 13 10 SGND
IN
PGND PGND
PWM/SYNC 4 9 SD
PWM/SYNC 4 9 SD
5
V 8 FB
CC
V 5 8 FB
CC RT 6 7 V
C
RT 6 7 V
C
MSE PACKAGE
12-LEAD PLASTIC MSOP
DE PACKAGE
T = 150?C, ? = 40?C/W (NOTE 5), ? = 10?C/W
JMAX JA JC
12-LEAD (4mm ? 3mm) PLASTIC DFN
EXPOSED PAD (PIN 13) IS PGND,
T = 125?C, ? = 43?C/W (NOTE 5), ? = 5?C/W
JMAX JA JC
MUST BE SOLDERED TO PCB FOR RATED THERMAL PERFORMANCE
EXPOSED PAD (PIN 13) IS PGND,
MUST BE SOLDERED TO PCB FOR RATED THERMAL PERFORMANCE
o r Der i n F Ma T
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC3122EDE#PBF LTC3122EDE#TRPBF 3122 12-Lead (4mm ? 3mm) Plastic DFN ?40?C to 125?C
LTC3122IDE#PBF LTC3122IDE#TRPBF 3122 12-Lead (4mm ? 3mm) Plastic DFN ?40?C to 125?C
LTC3122EMSE#PBF LTC3122EMSE#TRPBF 3122 12-Lead Plastic MSOP ?40?C to 125?C
LTC3122IMSE#PBF LTC3122IMSE#TRPBF 3122 12-Lead Plastic MSOP ?40?C to 125?C
LTC3122HMSE#PBF LTC3122HMSE#TRPBF 3122 12-Lead Plastic MSOP ?40?C to 150?C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Consult LTC Marketing for information on non-standard lead based finish parts.
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/
3122fa
2
For more information www.linear.com/LTC3122
ion or
ion igura on
ings bsoluPOWER LOSS (W)
LTC3122
15V, 2.5A Synchronous
Step-Up DC/DC Converter
with Output Disconnect
Fea T Descrip T
?
n
V Range: 1.8V to 5.5V, 500mV After Start-Up The LTC 3122 is a synchronous step-up DC/DC converter
IN
n
Output Voltage Range: 2.2V to 15V with true output disconnect and inrush current limiting. The
n
800mA Output Current for V = 5V and V = 12V 2.5A current limit along with the ability to program output
IN OUT
n
Output Disconnects from Input When Shut Down voltages up to 15V makes the LTC3122 well suited for a
n
Synchronous Rectification: Up to 95% Efficiency variety of demanding applications. Once started, opera-
n
Inrush Current Limit tion will continue with inputs down to 500mV, extending
n
Up to 3MHz Adjustable Switching Frequency runtime in many applications.
Synchronizable to External Clock
The LTC3122 features output disconnect in shutdown,
?
n
Selectable Burst Mode Operation: 25?A I
Q
dramatically reducing input power drain and enabling
n
Output Overvoltage Protection
V to completely discharge. Adjustable PWM switching
OUT
n
Soft-Start
from 100kHz to 3MHz optimizes applications for highest
n
<1?A I in Shutdown
Q
efficiency or smallest solution footprint. The oscillator
n
12-Lead, 3mm ? 4mm ? 0.75mm Thermally
can also be synchronized to an external clock for noise
Enhanced DFN and MSOP Packages
sensitive applications. Selectable Burst Mode operation
reduces quiescent current to 25?A, ensuring high efficiency
a T
across the entire load range. An internal soft-start limits
inrush current during start-up.
n
RF Power
n
Piezo Actuators
Other features include a <1?A shutdown current and ro-
n
Small DC Motors
bust protection under short-circuit, thermal overload, and
n
12V Analog Rail From Battery, 5V, or Backup Capacitor
output overvoltage conditions. The LTC3122 is offered in
both a low profile 12-lead (3mm ? 4mm ? 0.75 mm) DFN
L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks
and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the
package and a 12-lead thermally enhanced MSOP package.
property of their respective owners.
Typical a T
5V to 12V Synchronous Boost Converter with Output Disconnect Efficiency Curve
100 10
3.3?H
V
IN
Burst Mode
5V 90
OPERATION
SW 80
V
OUT
V V
12V
IN OUT
70
1
800mA
LTC3122
PWM
SD
OFF ON 100nF 60
4.7?F
BURST PWM PWM/SYNC CAP 50
1.02M
40
RT FB
22?F
0.1
30
PWM POWER LOSS
V V
113k
CC C
20
SGND PGND 210k
57.6k
10
10pF
4.7?F 390pF
0 0.01
0.01 0.1 1 10 100 1000
LOAD CURRENT (mA)
3122 TA01b
3122 TA01a
3122fa
1
For more information www.linear.com/LTC3122
EFFICIENCY (%)
ion pplica
ions pplica
ion uresPOWER LOSS (W)
LTC3122
15V, 2.5A Synchronous
Step-Up DC/DC Converter
with Output Disconnect
Fea T Descrip T
?
n
V Range: 1.8V to 5.5V, 500mV After Start-Up The LTC 3122 is a synchronous step-up DC/DC converter
IN
n
Output Voltage Range: 2.2V to 15V with true output disconnect and inrush current limiting. The
n
800mA Output Current for V = 5V and V = 12V 2.5A current limit along with the ability to program output
IN OUT
n
Output Disconnects from Input When Shut Down voltages up to 15V makes the LTC3122 well suited for a
n
Synchronous Rectification: Up to 95% Efficiency variety of demanding applications. Once started, opera-
n
Inrush Current Limit tion will continue with inputs down to 500mV, extending
n
Up to 3MHz Adjustable Switching Frequency runtime in many applications.
Synchronizable to External Clock
The LTC3122 features output disconnect in shutdown,
?
n
Selectable Burst Mode Operation: 25?A I
Q
dramatically reducing input power drain and enabling
n
Output Overvoltage Protection
V to completely discharge. Adjustable PWM switching
OUT
n
Soft-Start
from 100kHz to 3MHz optimizes applications for highest
n
<1?A I in Shutdown
Q
efficiency or smallest solution footprint. The oscillator
n
12-Lead, 3mm ? 4mm ? 0.75mm Thermally
can also be synchronized to an external clock for noise
Enhanced DFN and MSOP Packages
sensitive applications. Selectable Burst Mode operation
reduces quiescent current to 25?A, ensuring high efficiency
a T
across the entire load range. An internal soft-start limits
inrush current during start-up.
n
RF Power
n
Piezo Actuators
Other features include a <1?A shutdown current and ro-
n
Small DC Motors
bust protection under short-circuit, thermal overload, and
n
12V Analog Rail From Battery, 5V, or Backup Capacitor
output overvoltage conditions. The LTC3122 is offered in
both a low profile 12-lead (3mm ? 4mm ? 0.75 mm) DFN
L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks
and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the
package and a 12-lead thermally enhanced MSOP package.
property of their respective owners.
Typical a T
5V to 12V Synchronous Boost Converter with Output Disconnect Efficiency Curve
100 10
3.3?H
V
IN
Burst Mode
5V 90
OPERATION
SW 80
V
OUT
V V
12V
IN OUT
70
1
800mA
LTC3122
PWM
SD
OFF ON 100nF 60
4.7?F
BURST PWM PWM/SYNC CAP 50
1.02M
40
RT FB
22?F
0.1
30
PWM POWER LOSS
V V
113k
CC C
20
SGND PGND 210k
57.6k
10
10pF
4.7?F 390pF
0 0.01
0.01 0.1 1 10 100 1000
LOAD CURRENT (mA)
3122 TA01b
3122 TA01a
3122fa
1
For more information www.linear.com/LTC3122
EFFICIENCY (%)
ion pplica
ions pplica
ion uresLTC3122
a Te Maxi Mu M r a T
(Note 1)
V Voltage .................................................. ?0.3V to 6V All Other Pins ............................................... ?0.3V to 6V
IN
V Voltage ............................................ ?0.3V to 18V Operating Junction Temperature Range (Notes 3, 4)
OUT
SW Voltage (Note 2) .................................. ?0.3V to 18V LTC3122E/LTC3122I .......................... ?40?C to 125?C
SW Voltage (Pulsed < 100ns) (Note 2) ....... ?0.3V to 19V LTC3122H .......................................... ?40?C to 150?C
V , RT Voltage .......................................... ?0.3V to V Storage Temperature Range .................. ?65?C to 150?C
C CC
CAP Voltage MSE Lead Temperature (Soldering, 10sec) ...........300?C
V < 5.7V ............................?0.3V to (V + 0.3V)
OUT OUT
5.7V = V = 11.7V...... (V ? 6V) to (V + 0.3V)
OUT OUT OUT
V > 11.7V .................................(V ? 6V) to 12V
OUT OUT
p in c F T
TOP VIEW
TOP VIEW
SW 1 12 CAP
SW 1 12 CAP
PGND 2 11 V
OUT
PGND 2 11 V
OUT
V 3 10 SGND
IN
13 V 3 13 10 SGND
IN
PGND PGND
PWM/SYNC 4 9 SD
PWM/SYNC 4 9 SD
5
V 8 FB
CC
V 5 8 FB
CC RT 6 7 V
C
RT 6 7 V
C
MSE PACKAGE
12-LEAD PLASTIC MSOP
DE PACKAGE
T = 150?C, ? = 40?C/W (NOTE 5), ? = 10?C/W
JMAX JA JC
12-LEAD (4mm ? 3mm) PLASTIC DFN
EXPOSED PAD (PIN 13) IS PGND,
T = 125?C, ? = 43?C/W (NOTE 5), ? = 5?C/W
JMAX JA JC
MUST BE SOLDERED TO PCB FOR RATED THERMAL PERFORMANCE
EXPOSED PAD (PIN 13) IS PGND,
MUST BE SOLDERED TO PCB FOR RATED THERMAL PERFORMANCE
o r Der i n F Ma T
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC3122EDE#PBF LTC3122EDE#TRPBF 3122 12-Lead (4mm ? 3mm) Plastic DFN ?40?C to 125?C
LTC3122IDE#PBF LTC3122IDE#TRPBF 3122 12-Lead (4mm ? 3mm) Plastic DFN ?40?C to 125?C
LTC3122EMSE#PBF LTC3122EMSE#TRPBF 3122 12-Lead Plastic MSOP ?40?C to 125?C
LTC3122IMSE#PBF LTC3122IMSE#TRPBF 3122 12-Lead Plastic MSOP ?40?C to 125?C
LTC3122HMSE#PBF LTC3122HMSE#TRPBF 3122 12-Lead Plastic MSOP ?40?C to 150?C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Consult LTC Marketing for information on non-standard lead based finish parts.
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/
3122fa
2
For more information www.linear.com/LTC3122
ion or
ion igura on
ings bsoluLTC3122
e Trical c T TThe l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T = 25?C (Note 3). V = 3.6V, V = 12V, RT = 57.6k unless otherwise noted.
A IN OUT
PARAMETER CONDITIONS MIN. TYP MAX UNITS
Minimum Start-Up Voltage V = 0V l 1.7 1.8 V
OUT
l
Input Voltage Range After V = 2.2V 0.5 5.5 V
OUT
Output Voltage Adjust Range l 2.2 15 V
l
Feedback Voltage 1.178 1.202 1.225 V
Feedback Input Current V = 1.4V 1 50 nA
FB
Quiescent Current, Shutdown V = 0V, V = 0V, Not Including Switch Leakage 0.01 1 ?A
SD OUT
Quiescent Current, Active V = 0V, Measured On V , Non-Switching 500 700 ?A
C IN
Quiescent Current, Burst Measured on V , V > 1.4V 25 40 ?A
IN FB
Measured on V , V > 1.4V 10 20 ?A
OUT FB
l
N-channel MOSFET Switch Leakage Current V = 15V, V = 15V, V = 0V 0.1 30 ?A
SW OUT C
P-channel MOSFET Switch Leakage Current V = 0V, V = 15V, V = 0V l 0.1 70 ?A
SW OUT SD
N-channel MOSFET Switch On-Resistance 0.121 O
P-channel MOSFET Switch On-Resistance 0.188 O
N-channel MOSFET Current Limit l 2.5 3.5 4.5 A
l
Maximum Duty Cycle V = 1.0V 90 94 %
FB
Minimum Duty Cycle V = 1.4V l 0 %
FB
l
Switching Frequency 0.85 1 1.15 MHz
SYNC Frequency Range l 0.1 3 MHz
l
PWM/SYNC Input High 0.9 ?V V
CC
PWM/SYNC Input Low l 0.1?V V
CC
PWM/SYNC Input Current V = 5.5V 0.01 1 ?A
PWM/SYNC
CAP Clamp Voltage V > 6.1V, Referenced to V ?5.2 ?5.6 ?6.0 V
OUT OUT
V Regulation Voltage V < 2.8V, V > 5V 4 4.25 4.5 V
CC IN OUT
Error Amplifier Transconductance l 70 95 120 ?S
Error Amplifier Output Current ?25 ?A
Soft-Start Time 10 ms
SD Input High l 1.6 V
l
SD Input Low 0.25 V
SD Input Current V = 5.5V 1 2 ?A
SD
Note 1: Stresses beyond those listed under Absolute Maximum Ratings temperature range. The LTC3122H is guaranteed to meet specifications
may cause permanent damage to the device. Exposure to any Absolute over the full ?40?C to 150?C operating junction range. The junction
Maximum Rating condition for extended periods may affect device temperature (T in ?C) is calculated from the ambient temperature (T in
J A
reliability and lifetime. ?C) and power dissipation (P in Watts) according to the formula: T = T
D J A
+ (P ? ? ) where ? is the thermal impedance of the package.
Note 2: Voltage transients on the SW pin beyond the DC limit specified in D JA JA
the Absolute Maximum Ratings are non-disruptive to normal operations Note 4: The LTC3122 includes overtemperature protection that is intended
when using good layout practices, as shown on the demo board or to protect the device during momentary overload conditions. Junction
described in the data sheet or application notes. temperature will exceed 150?C when overtemperature shutdown is active.
Continuous operation above the specified maximum operating junction
Note 3: The LTC3122 is tested under pulsed load conditions such that
temperature may result in device degradation or failure.
T ? T . The LTC3122E is guaranteed to meet performance specifications
A J
from 0?C to 85?C. Specifications over the ?40?C to 125?C operating Note 5: Failure to solder the exposed backside of the package to the PC
junction temperature range are assured by design, characterization and board ground plane will result in a thermal impedance much higher than
correlation with statistical process controls. The LTC3122I is guaranteed the rated package specifications.
to meet specifications over the full ?40?C to 125?C operating junction
3122fa
3
For more information www.linear.com/LTC3122
ics eris harac lec