FEATURES
n Delivers 3.3V at 200mA from a Single Alkaline/
NiMH Cell or 3.3V at 400mA from Two Cells
n VIN Start-Up Voltage: 700mV
n 0.50V to 5.5V Input Range
n 1.6V to 5.25V VOUT Range
n Up to 94% Efficiency
n Output Disconnect
n 2MHz Fixed Frequency Operation
n VIN > VOUT Operation
n Integrated Soft-Start
n Current Mode Control with Internal Compensation
n Low Noise PWM Operation
n Internal Synchronous Rectifier
n Logic Controlled Shutdown: <1µA
n Anti-Ringing Control
n Low Profile (2mm × 3mm × 0.75mm) DFN Package
APPLICATIONS
n Medical Instruments
n Flash-Based MP3 Players
n Noise Canceling Headphones
n Wireless Mice
n Bluetooth Headsets
LTC3528B-2
1A, 2MHz Synchronous
Step-Up DC/DC Converter
in 2mm × 3mm DFN
DESCRIPTION
The LTC®3528B-2 is a synchronous, fixed frequency
step-up DC/DC converter with output disconnect. High
efficiency synchronous rectification, in addition to a 700mV
start-up voltage and operation down to 500mV once
started, provides longer run-time for single or multiple
cell battery-powered products.
A switching frequency of 2MHz minimizes solution
footprint by allowing the use of tiny, low profile induc-
tors and ceramic capacitors. The current mode PWM is
internally compensated, simplifying the design process.
The LTC3528B-2 features continuous switching at light
loads. Anti-ringing circuitry reduces EMI by damping the
inductor in discontinuous mode. Additional features include
a low shutdown current, open-drain power good output,
short-circuit protection and thermal overload protection.
The LTC3528B-2 is offered in an 8-lead 2mm × 3mm ×
0.75mm DFN package.
L, LT, LTC, LTM, 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.
TYPICAL APPLICATION
2.2µH
VIN
1.8V TO 3.2V
4.7µF
OFF ON
SW
VIN
VOUT
LTC3528B-2
PGOOD FB
SHDN
GND
499k
287k
68pF
VOUT
3.3V
400mA
10µF
35282 TA01a
Efficiency and Power Loss
100
VOUT = 3.3V
90 VIN = 2.4V
80
1000
70
EFFICIENCY
100
60
50
POWER LOSS
40
30
10
20
10
0
1
0.1
1
10
100
1000
LOAD CURRENT (mA)
35282 TA01b
3528b2fa
1
