LTC3255
Wide V Range
IN
Fault Protected 50mA
Step-Down Charge Pump
FEATURES DESCRIPTION
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Input Voltage Range: 4V to 48V The LTC 3255 is a switched-capacitor step-down DC/DC
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Adjustable Regulated Output: 2.4V to 12.5V converter that produces a regulated output (2.4V to 12.5V
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Output Current: 50mA Maximum adjustable) from a 4V to 48V input. In applications where
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16A Quiescent Current in Regulation at No Load the input voltage exceeds twice the output voltage, 2:1
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Input Fault Protection from 52V to 60V capacitive charge pumping extends output current capabil-
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Multimode Charge Pump (2:1, 1:1) with Automatic ity beyond input supply current limits. At no load, Burst
Mode Switching Maintains Regulation Over Wide Mode operation cuts V quiescent current to 16A.
IN
V Range
IN
With its integrated V shunt regulator, the LTC3255
IN
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Input Voltage Shunt Mode for Current-Fed Applications
excels in 4mA to 20mA current loop applications. The
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Power Good Output
device enables current multiplication; a 4mA input current
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Overtemperature and Short-Circuit Protection
can power a 7.4mA load continuously. Alternatively, the
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Operating Junction Temperature: 150C Maximum
LTC3255 serves as a higher efficiency replacement for
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Thermally Enhanced 10-Lead MSOP and 10-Lead
linear regulators and provides a space-saving inductor-
(3mm 3mm) DFN packages
free alternative to buck DC/DC converters.
APPLICATIONS
The LTC3255 withstands reverse-polarity input supplies
and output short-circuits without damage. Safety features
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Industrial Control, Factory Automation, Sensors, and
including current limit and overtemperature protection
SCADA Systems
further enhance robustness. The LTC3255 is available in
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Housekeeping Power Supplies
thermally enhanced 10-lead MSOP and low profile 3mm
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Current-Boosting Voltage Regulators for 4mA to
3mm 10-lead DFN packages.
20mA Current Loops
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
property of their respective owners.
TYPICAL APPLICATION
Available Output Current
vs Input Current
7.4mA DC Supply from 4mA to 20mA Current Loop
40
1F
37
34
OUTPUT
+ 31
C C
+ V V 3.3V
IN OUT
28
7.4mA
AVAILABLE
EN LTC3255 220k
25
INCREASED
I
OUT
I CAPABILITY
22 OUT
PGOOD PGOOD
4mA TO 20mA INPUT
1F 10F
19
>10V COMPLIANCE 2.15M
SHUNT
16
BIAS GND FB
13
1.21M
INPUT
0.1F
10
CURRENT
3255 TA01a
7
4
4 6 8 10 12 14 16 18 20
INPUT CURRENT (mA)
3255 TA01b
3255f
1
For more information www.linear.com/LTC3255
AVAILABLE OUTPUT CURRENT (mA)LTC3255
ABSOLUTE MAXIMUM RATINGS (Notes 1, 2)
V , EN ........................................................ 52V to 60V I When V < 0V (Note 5) .....................100A
IN PGOOD PGOOD
V ..........................................................................15V Operating Junction Temperature
OUT
V Short-Circuit Duration (Note 6) ............... Indefinite Range (Notes 3, 6) ................................. 55C to 150C
OUT
I When V < 0V (Note 4) .............................50mA Storage Temperature Range .................. 65C to 150C
VOUT OUT
FB .............................................................................6V Lead Temperature (Soldering, 10 sec)
PGOOD ......................................................................15V MSE Only ..........................................................300C
PIN CONFIGURATION
TOP VIEW
TOP VIEW
+
C 1 10 V
IN
+
C 1 10 V
IN
V 2 9 C
OUT
V 2 9 C
OUT
11 11
FB 3 8 GND
FB 3 8 GND
GND GND
SHUNT 4 7 BIAS
SHUNT 4 7 BIAS
PGOOD 5 6 EN
PGOOD 5 6 EN
MSE PACKAGE
10-LEAD PLASTIC MSOP
DD PACKAGE
T = 150C, = 40C/W
JMAX JA
10-LEAD (3mm 3mm) PLASTIC DFN
EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB
T = 150C, = 43C/W
JMAX JA
EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB
ORDER INFORMATION
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC3255EDD#PBF LTC3255EDD#TRPBF LGHD 10-Lead (3mm 3mm) Plastic DFN 40C to 125C
LTC3255IDD#PBF LTC3255IDD#TRPBF LGHD 40C to 125C
10-Lead (3mm 3mm) Plastic DFN
LTC3255HDD#PBF LTC3255HDD#TRPBF LGHD 10-Lead (3mm 3mm) Plastic DFN 40C to 150C
LTC3255MPDD#PBF LTC3255MPDD#TRPBF LGHD 10-Lead (3mm 3mm) Plastic DFN 55C to 150C
LTC3255EMSE#PBF LTC3255EMSE#TRPBF LTGHF 10-Lead Plastic MSOP 40C to 125C
LTC3255IMSE#PBF LTC3255IMSE#TRPBF LTGHF 10-Lead Plastic MSOP 40C to 125C
LTC3255HMSE#PBF LTC3255HMSE#TRPBF LTGHF 10-Lead Plastic MSOP 40C to 150C
LTC3255MPMSE#PBF LTC3255MPMSE#TRPBF LTGHF 10-Lead Plastic MSOP 55C to 150C
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 nonstandard lead based finish parts.
For more information on lead free part marking, go to: