LTC3245 Datasheet, PDF (1/16 Pages) Linear Technology – Wide VIN Range, Low Noise, 250mA Buck-Boost Charge Pump

LTC3245
Features
Wide V_IN Range,
Low Noise, 250mA Buck-Boost
Charge Pump
Description
n _{2.7V to 38V VIN Range}
n _{IQ = 18µA Operating; 4μA in Shutdown}
n _{12V to 5V Efficiency = 81%}
n _{Multimode Operation (2:1, 1:1, 1:2) with Automatic}
Mode Switching
n _{Low Noise, Constant Frequency Operation}
n _{Pin Selectable Burst Mode}^® _Operation
n _{VOUT: Fixed 3.3V, 5V or Adjustable (2.5V to 5V)}
n _{IOUT Up to 250mA}
n _{Overtemperature and Short-Circuit Protection}
n _{Operating Junction Temperature: 150°C Maximum}
n _{Thermally Enhanced 12-Pin MSOP and Low Profile}
12-Pin (3mm × 4mm) DFN Packages
Applications
n _{Automotive ECU/CAN Transceiver Supplies}
n _{Industrial Housekeeping Supplies}
n _{Low Power 12V to 5V Conversion}
L, LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks
and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the
property of their respective owners.
The LTC^®3245 is a switched capacitor buck-boost DC/DC
converter that produces a regulated output (3.3V, 5V or
adjustable) from a 2.7V to 38V input. The device uses
switched capacitor fractional conversion to maintain
regulation over a wide range of input voltage. Internal
circuitry automatically selects the conversion ratio to
optimize efficiency as input voltage and load conditions
vary. No inductors are required.
The unique constant frequency architecture provides a
lower noise output than conventional charge pump regu-
lators. To optimize efficiency at the expense of slightly
higher output ripple, the device has pin selectable Burst
Mode operation.
Low operating current (20μA with no load, 4μA in shut-
down) and low external parts count (three small ceramic
capacitors) make the LTC3245 ideally suited for low power,
space constrained automotive/industrial applications. The
device is short-circuit and overtemperature protected, and
is available in thermally enhanced 12-pin MSOP and low
profile 3mm × 4mm 12-pin DFN packages.
Typical Application
Efficient Regulated 5V Output
1µF
C⁺
C^–
LTC3245
V_IN = 2.7V TO 38V
V_IN
V_OUT
SEL2 OUTS/ADJ
1µF
BURST PGOOD
SEL1
GND
3245 TA01a
500k
V_OUT = 5V
I_OUT UP TO 250mA
10µF
5V_OUT Efficiency vs Output Current
90
400
V_IN = 12V
80
350
EFFICIENCY
70
300
60
250
50
200
40
150
P_LOSS
30
100
20
50
10
0.1
0
1
10
100
1000
I_OUT (mA)
3245 TA01b
3245f
For more information www.linear.com/LTC3245
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