FEATURES
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LTC3526/LTC3526B
500mA 1MHz Synchronous
Step-Up DC/DC Converters
in 2mm
×
2mm DFN
DESCRIPTION
The LTC
®
3526/LTC3526B are synchronous, fixed frequency
step-up DC/DC converters with output disconnect. Syn-
chronous rectification enables high efficiency in the low
profile 2mm
×
2mm DFN package. Battery life in single
AA/AAA powered products is extended further with an
850mV start-up voltage and operation down to 500mV
once started.
A switching frequency of 1MHz minimizes solution foot-
print by allowing the use of tiny, low profile inductors and
ceramic capacitors. The current mode PWM design is
internally compensated, reducing external parts count. The
LTC3526 features automatic Burst Mode operation at light
load conditions, while the LTC3526B features continuous
switching at light loads. Anti-ringing control circuitry also
reduces EMI concerns by damping the inductor in discon-
tinuous mode. Additional features include a low shutdown
current of under 1μA and thermal shutdown.
The LTC3526/LTC3526B are housed in a 2mm
×
2mm
×
0.75mm DFN package.
, LT, LTC, LTM and Burst Mode are registered trademarks of Linear Technology
Corporation. All other trademarks are the property of their respective owners.
Delivers 3.3V at 100mA from a Single Alkaline/
NiMH Cell or 3.3V at 200mA from Two Cells
V
IN
Start-Up Voltage: 850mV
1.6V to 5.25V V
OUT
Range
Up to 94% Efficiency
Output Disconnect
1MHz Fixed Frequency Operation
V
IN
> V
OUT
Operation
Integrated Soft-Start
Current Mode Control with Internal Compensation
Automatic Burst Mode
®
Operation with 9μA
Quiescent Current (LTC3526)
Low Noise PWM Operation (LTC3526B)
Internal Synchronous Rectifier
Logic Controlled Shutdown (I
Q
< 1μA)
Anti-Ringing Control
Low Profile (2mm
×
2mm
×
0.75mm) DFN Package
APPLICATIONS
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Medical Instruments
Flash-Based MP3 Players
Noise Canceling Headphones
Wireless Mice
Bluetooth Headsets
TYPICAL APPLICATION
4.7μH
LTC3526 Efficiency and Power Loss vs Load Current
100
90
80
V
IN
= 2.4V
EFFICIENCY
100
POWER LOSS (mW)
1000
V
IN
1.6V TO 3.2V
1μF
OFF ON
V
IN
V
OUT
1.78M
FB
1M
V
OUT
3.3V
200mA
4.7μF
EFFICIENCY (%)
SW
70
60
50
40
30
POWER LOSS
1
10
LTC3526
SHDN
GND
3526 TA01a
20
10
0
0.01
0.1
1
10
100
0.1
0.01
1000
3526 TA01b
LOAD CURRENT (mA)
3526bfb
1
LINER [ LINEAR TECHNOLOGY ]
