LTC3526L_15 Datasheet, PDF (1/16 Pages) Linear Technology – 550mA 1MHz Synchronous Step-Up DC/DC Converters

Features
n _{Delivers 3.3V at 100mA from a Single Alkaline/}
NiMH Cell or 3.3V at 200mA from Two Cells
n _{VIN Start-Up Voltage: 680mV}
n _{1.5V to 5.25V VOUT Range}
n _{Up to 94% Efficiency}
n _{Output Disconnect}
n _{1MHz Fixed Frequency Operation}
n _{VIN > VOUT Operation}
n _{Integrated Soft-Start}
n _{Current Mode Control with Internal Compensation}
n _{Burst Mode}^® _{Operation with 9µA IQ (LTC3526L)}
n _{Low Noise PWM Operation (LT3526LB)}
n _{Internal Synchronous Rectifier}
n _{Logic Controlled Shutdown (IQ < 1µA)}
n _{Anti-Ring Control}
n _{Low Profile (2mm × 2mm × 0.75mm)}
DFN-6 Package
Applications
n _{Medical Instruments}
n _{Noise Canceling Headphones}
n _{Wireless Mice}
n _{Bluetooth Headsets}
LTC3526L/LTC3526LB
550mA 1MHz Synchronous
Step-Up DC/DC Converters
in 2mm × 2mm DFN
Description
The LTC^®3526L/LTC3526LB are synchronous, fixed
frequency step-up DC/DC converters with output discon-
nect. Synchronous rectification enables high efficiency in
the low profile 2mm × 2mm DFN package. Battery life in
single AA/AAA powered products is extended further with
a 680mV 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 LTC3526L features Burst Mode operation at light load
conditions allowing it to maintain high efficiency over a
wide range of load. The LTC3526LB features fixed frequency
operation for low noise applications. Anti-ring circuitry
reduces EMI by damping the inductor in discontinuous
mode. Additional features include a low shutdown current
of under 1µA and thermal shutdown.
The LTC3526L/LTC3526LB are housed in a 2mm × 2mm
× 0.75mm DFN package.
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
4.7µH
V_IN
1.6V TO 3.2V
4.7µF
OFF ON
SW
V_IN
V_OUT
LTC3526L
SHDN FB
GND
1.78M
V_OUT
3.3V
200mA
4.7µF
1M
3526l TA01a
Efficiency and Power Loss vs Load Current
100
V_IN = 2.4V
90
80
EFFICIENCY
1000
100
70
60
10
50
POWER LOSS
40
1
30
20
0.1
10
0
0.01
0.1
1
0.01
10 100 1000
LOAD CURRENT (mA)
3526l TA01b
3526lfc