LTC3255_15 Datasheet, PDF (1/16 Pages) Linear Technology – Wide VIN Range Fault Protected 50mA Step-Down Charge Pump

LTC3255
Wide V_IN Range
Fault Protected 50mA
Step-Down Charge Pump
FEATURES
DESCRIPTION
n _{Input Voltage Range: 4V to 48V}
n _{Adjustable Regulated Output: 2.4V to 12.5V}
n _{Output Current: 50mA Maximum}
n _{16μA Quiescent Current in Regulation at No Load}
n _{Input Fault Protection from –52V to 60V}
n _{Multimode Charge Pump (2:1, 1:1) with Automatic}
Mode Switching Maintains Regulation Over Wide
V_IN Range
n _{Input Voltage Shunt Mode for Current-Fed Applications}
n _{Power Good Output}
n _{Overtemperature and Short-Circuit Protection}
n _{Operating Junction Temperature: 150°C Maximum}
n _{Thermally Enhanced 10-Lead MSOP and 10-Lead}
(3mm × 3mm) DFN packages
APPLICATIONS
n _{Industrial Control, Factory Automation, Sensors, and}
SCADA Systems
n _{Housekeeping Power Supplies}
n _{Current-Boosting Voltage Regulators for 4mA to}
20mA Current Loops
The LTC^®3255 is a switched-capacitor step-down DC/DC
converter that produces a regulated output (2.4V to 12.5V
adjustable) from a 4V to 48V input. In applications where
the input voltage exceeds twice the output voltage, 2:1
capacitive charge pumping extends output current capabil-
ity beyond input supply current limits. At no load, Burst
Mode^® operation cuts V_IN quiescent current to 16µA.
With its integrated V_IN shunt regulator, the LTC3255
excels in 4mA to 20mA current loop applications. The
device enables current multiplication; a 4mA input current
can power a 7.4mA load continuously. Alternatively, the
LTC3255 serves as a higher efficiency replacement for
linear regulators and provides a space-saving inductor-
free alternative to buck DC/DC converters.
The LTC3255 withstands reverse-polarity input supplies
and output short-circuits without damage. Safety features
including current limit and overtemperature protection
further enhance robustness. The LTC3255 is available in
thermally enhanced 10-lead MSOP and low profile 3mm
× 3mm 10-lead DFN packages.
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
7.4mA DC Supply from 4mA to 20mA Current Loop
1µF
+
4mA TO 20mA INPUT
>10V COMPLIANCE
–
V_IN ^C+
C^– _VOUT
EN LTC3255
1µF
SHUNT
PGOOD
BIAS GND
FB
0.1µF
220k
PGOOD
2.15M
OUTPUT
3.3V
7.4mA
10µF
1.21M
3255 TA01a
For more information www.linear.com/LTC3255
Available Output Current
vs Input Current
40
37
34
31
28
25
22
AVAILABLE
I_OUT
INCREASED
I_OUT CAPABILITY
19
16
13
10
INPUT
CURRENT
7
4
4 6 8 10 12 14 16 18 20
INPUT CURRENT (mA)
3255 TA01b
3255f
1