LTC3428 Datasheet, PDF (1/12 Pages) Linear Technology – 4A, 2MHz Dual Phase Step-Up DC/DC Converter in 3mm 3mm DFN

FEATURES
■ _{High Efficiency: Up to 92%}
■ _{2-Phase Control Reduces Output Voltage Ripple}
■ _{5V at 2A from 3.3V Input}
■ _{3.3V at 1.5A from 1.8V Input}
■ _{1.6V to 5.25V Adjustable Output Voltage}
■ _{1.6V to 4.5V Input Range}
■ _{Internal Soft-Start Operation}
■ _{Low Shutdown Current: <1µA}
■ _{Uses Small Surface Mount Components}
■ _{10-Pin 3mm × 3mm DFN Package}
U
APPLICATIO S
■ _{Networking Equipment}
■ _{Handheld Instruments}
■ _{Digital Cameras}
■ _{Distributed Power}
■ _{Local 3.3V to 5V Conversion}
TYPICAL APPLICATIO
LTC3428
4A, 2MHz Dual Phase
Step-Up DC/DC Converter
in 3mm × 3mm DFN
DESCRIPTIO
The LTC^®3428 is a 2-phase, current mode boost con-
verter, capable of supplying 2A at 5V from a 3.3V input.
Two 93mΩ, 2A N-channel MOSFET switches allow the
LTC3428 to deliver high efficiency from input voltages as
low as 1.6V.
External parts count and size are minimized by a 1MHz
switching frequency and a 2-phase design. Two phase
operation significantly reduces peak inductor currents
and capacitor ripple current, doubling the effective switch-
ing frequency and minimizing inductor and capacitor size.
External compensation allows the feedback loop response
to be optimized for a particular application.
Other features include: an active low shutdown pin re-
duces supply current to below 1µA, internal soft-start,
antiringing control and thermal shutdown. The LTC3428
is available in a low profile (0.75mm) 10-lead (3mm ×
3mm) DFN package.
, LTC and LT are registered trademarks of Linear Technology Corporation.
3.3V to 5V at 2A Converter
V_IN
3.3V
4.7µF***
10k
1000pF
OFF ON
22pF
V_IN
V_OUT
SHDN
SWA
V_C ^LTC3428 SWB
AGND
FB
PGNDA
PGNDB
2.2µH* 2.2µH*
**
**
22µF****
V_OUT
5V/2A
383k
121k
* TOKO FDV06302R2
** PHILIPS PMEG1020
*** TAIYO YUDEN X5R JMK212BJ475MD
**** TAIYO YUDEN X5R JMK316BJ226ML
3428 TA01
Efficiency vs Load Current
95
90
85
80
75
70
65
60
55
50
45
0.1
V_IN = 3.3V
V_OUT = 5V
L = 2.2µH
1
2
LOAD CURRENT (A)
3428 TA02
3428f
1