LTC3525-3_15 Datasheet, PDF (1/16 Pages) Linear Technology – 400mA Micropower Synchronous Step-Up DC/DC Converter with Output Disconnect

LTC3525-3/
LTC3525-3.3/LTC3525-5
400mA Micropower
Synchronous Step-Up DC/DC
Converter with Output Disconnect
Features
n _{Up to 95% Efficiency}
n _{Output Disconnect and Inrush Current Limit}
n _{Fixed Output Voltages of 3V, 3.3V or 5V}
n _{Delivers 65mA at 3V from a 1V Input}
n _{Delivers 60mA at 3.3V from a 1V Input,}
or 140mA at 3.3V from a 1.8V Input
n _{Delivers 175mA at 5V from a 3V Input}
n _{Burst Mode}^® _{Operation: IQ = 7µA}
n _{Only Three External Components}
n _{VIN > VOUT Operation}
n _{<1µA Shutdown Current}
n _{Antiringing Control}
n _{Short-Circuit and Overtemperature Protection}
n _{Very Low Profile of 1mm}
n _{Tiny 6-Lead SC70 Package}
Applications
n _{MP3 Players}
n _{Portable Instruments}
n _{Glucose Meters}
n _{Digital Cameras}
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. Patents pending.
Description
The LTC^®3525-3/LTC3525-3.3/LTC3525-5 are high efficiency
synchronous step-up DC/DC converters with output discon-
nect that can start up with an input as low as 0.85V. 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 3V, 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 applications.
Other features include <1µA shutdown current, anti-
ringing control and thermal shutdown. The LTC3525 is
available in a tiny 6-Lead SC70 package.
List of LTC3525 Options
PART NAME INPUT START-UP
VOLTAGE
LTC3525-3
0.85V
LTC3525-3.3
0.85V
LTC3525-5
0.85V
LTC3525D-3.3
0.85V
LTC3525L-3
0.7V
OUTPUT
VOLTAGE
3V
3.3V
5V
3.3V
3V
V_OUT STATUS IN
SHUTDOWN MODE
Output Disconnect
Output Disconnect
Output Disconnect
Pass Through Mode
Output Disconnect
Typical Application
L1*
10µH
V_IN
1V TO 1.6V
OFF ON
1µF
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
For more information www.linear.com/LTC3525
3525fc
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