LTC3458L
1
3458lfa
FEATURES
DESCRIPTIO
U
APPLICATIO S
U
TYPICAL APPLICATIO
U
■
High Efficiency: Up to 95%
■
Inrush Current Limiting and Output Disconnect
■
Programmable Output Voltages up to 6V
■
1.5V to 6V Input Range
■
Programmable/Synchronizable Fixed Frequency
Operation up to 1.5MHz
■
Programmable Automatic Burst Mode
®
Operation
■
Current Mode Control with Programmable Soft-Start
Period and Peak Current Limit
■
0.2Ω N-Channel and 0.3Ω P-Channel Switches
■
Ultralow Quiescent Currents: 12μA Sleep, <1μA in
Shutdown
■
12-Pin 4mm × 3mm Thermally Enhanced DFN
Package
■
Point-of-Load Regulators
■
USB V
BUS
Power
■
Portable GPS
■
MP3 Players
1.7A, 1.5MHz Synchronous
Step-Up DC/DC Converter
with Output Disconnect
The LTC
®
3458L is a high efficiency, current mode, fixed
frequency, step up DC/DC converter with true output
disconnect and inrush current limiting. The LTC3458L is
rated for up to 6V output and includes a 0.2Ω N-channel
MOSFET switch and a 0.3Ω P-channel MOSFET synchro-
nous rectifier. The LTC3458L is well suited for battery
powered applications and includes programmable output
voltage, switching frequency and loop compensation. The
oscillator frequency can be set up to 1.5MHz or synchro-
nized to an external clock.
Quiescent current is only 12μA during Burst Mode opera-
tion maximizing battery life in portable applications. The
Burst Mode current threshold, peak current limit, and soft-
start are externally programmable. Other features include
<1μA shutdown current, antiringing control, and thermal
limit. The LTC3458L is available in a low profile (0.75mm),
4mm × 3mm 12-pin DFN package.
Li-Ion to 5V at 1MHz
Li-Ion to 5V
OUT
V
IN
GND/PGND
SHDN
SYNC
R
T
I
LIM
SW
V
OUT
FB
COMP
SS
BURST
LTC3458L
Li Ion
3.1V TO 4.2V
2.2μF
7.4μH
ON OFF
200k 84.5k 133k
324k
33k
0.01μF
0.01μF
560pF
10pF
10pF
1M
22μF
X5R
V
OUT
5V
750mA
3458L TA01a
LOAD CURRENT (mA)
0.1
EFFICIENCY (%)
3.6 V
IN
POWER LOSS (mW)
100
95
90
85
80
75
70
65
60
1000
100
10
1
0.1
110
3458L TA01b
100 1000
4.2V
IN
3.1V
IN
POWER
LOSS
3.6V
IN
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All
other trademarks are the property of their respective owners. Burst Mode is a registered
trademark of Linear Technology Corporation. Protected by U.S. Patents including 5481178,
6580258, 6304066, 6127815, 6498466, 6611131.