Datasheet

LTC3428
1
3428fb
TYPICAL APPLICATION
DESCRIPTION
4A, 2MHz Dual Phase
Step-Up DC/DC Converter
in 3mm × 3mm DFN
The LTC
®
3428 is a 2-phase, current mode boost con-
verter, capable of supplying 2A at 5V from a 3.3V input.
Two 93m, 2A N-channel MOSFET switches allow the
LTC3428 to deliver high effi ciency 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 signifi cantly reduces peak inductor currents and
capacitor ripple current, doubling the effective switching
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 profi le (0.75mm) 10-lead (3mm ×
3mm) DFN package.
3.3V to 5V at 2A Converter
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other
trademarks are the property of their respective owners.
FEATURES
APPLICATIONS
n
High Effi ciency: Up to 92%
n
2-Phase Control Reduces Output Voltage Ripple
n
5V at 2A from 3.3V Input
n
3.3V at 1.5A from 1.8V Input
n
1.6V to 5.25V Adjustable Output Voltage
n
1.6V to 4.5V Input Range
n
Internal Soft-Start Operation
n
Low Shutdown Current: <1A
n
Uses Small Surface Mount Components
n
10-Pin 3mm × 3mm DFN Package
n
Networking Equipment
n
Handheld Instruments
n
Digital Cameras
n
Distributed Power
n
Local 3.3V to 5V Conversion
V
OUT
SWA
SWB
FB
PGNDB
V
IN
SHDN
V
C
AGND
PGNDA
LTC3428
383k
121k
22µF****
22pF
10k
1000pF
4.7µF***
V
IN
3.3V
V
OUT
5V/2A
3428 TA01
2.2µH*
2.2µH*
OFF ON
TOKO FDV06302R2
PHILIPS PMEG1020
TAIYO YUDEN X5R JMK212BJ475MD
TAIYO YUDEN X5R JMK316BJ226ML
*
**
***
****
**
**
LOAD CURRENT (A)
0.1
EFFICIENCY (%)
95
90
85
80
75
70
65
60
55
50
45
12
3428 TA02
V
IN
= 3.3V
V
OUT
= 5V
L = 2.2µH
Effi ciency vs Load Current