LTC3525-3.3 Datasheet, PDF (1/12 Pages) Linear Technology – 400mA Micropower Synchronous Step-Up DC/DC Converter with Output Disconnect

LTC3525-3.3/LTC3525-5
400mA Micropower
Synchronous Step-Up DC/DC
Converter with Output Disconnect
FEATURES
■ _{Up to 95% Efficiency}
■ _{Output Disconnect and Inrush Current Limit}
■ _{Fixed Output Voltages of 3.3V or 5V}
■ _{Delivers 60mA at 3.3V from a 1V Input,}
or 140mA at 3.3V from a 1.8V Input
■ _{Delivers 175mA at 5V from a 3V Input}
■ _{Burst Mode}^® _{Operation: IQ = 7µA}
■ _{Only Three External Components}
■ _{1V to 4.5V Input Range}
■ _{<1µA Shutdown Current}
■ _{Antiringing Control}
■ _{Short-Circuit and Overtemperature Protection}
■ _{Very low profile of 1mm}
■ _{Tiny 6-Pin SC-70 Package}
U
APPLICATIO S
■ _{MP3 Players}
■ _{Portable Instruments}
■ _{Glucose Meters}
■ _{Digital Cameras}
DESCRIPTIO
The LTC^®3525-3.3/LTC3525-5 are high efficiency syn-
chronous step-up DC/DC converters with output discon-
nect that can start up with an input as low as 1V. They offer
a compact, high efficiency alternative to charge pumps in
single cell or dual cell alkaline or Li-ion applications. Only
three small external components are required. The LTC3525
is offered in fixed output voltages of 3.3V or 5V.
The device includes a 0.5Ω N-channel MOSFET switch and
a 0.8Ω P-channel synchronous rectifier. Peak switch
current ranges from 150mA to 400mA, depending on load,
providing enhanced efficiency. Quiescent current is an
ultralow 7µA, maximizing battery life in portable applica-
tions.
Other features include <1µA shutdown current, anti-
ringing control and thermal shutdown. The LTC3525 is
available in a tiny 6-pin SC-70 package.
, LTC and LT are registered trademarks of Linear Technology Corporation.
Burst Mode is a registered trademark of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
Patents Pending
TYPICAL APPLICATIO
V_IN
1V to 1.6V
OFF ON
1µF
L1*
10µH
LTC3525-3.3
V_IN
SW
SHDN
V_OUT
GND
GND
V_OUT
3.3V
60mA
10µF
3525 TA01
*MURATA LQH32CN100K53
LTC3525-3.3 Efficiency and Power
Loss vs Load Current
100
100
90
80
10
EFFICIENCY
70
60
1
POWER LOSS
50
40
30
20
0.01 0.1
1
10
LOAD (mA)
0.1
V_IN = 3V
V_IN = 2.4V
V_IN = 1.2V
0.01
100 1000
LT3525 • TA02
3525f
1