LTC3458L Datasheet, PDF (1/16 Pages) Linear Technology – 1.7A, 1.5MHz Synchronous Step-Up DC/DC Converter with Output Disconnect

FEATURES
■ _{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
U
APPLICATIO S
■ _{Point-of-Load Regulators}
■ _{USB VBUS Power}
■ _{Portable GPS}
■ _{MP3 Players}
LTC3458L
1.7A, 1.5MHz Synchronous
Step-Up DC/DC Converter
with Output Disconnect
DESCRIPTIO
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.
, LTC and LT are registered trademarks of Linear Technology Corporation.
Burst Mode is a registered trademark of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
Protected by U.S. Patents including 5481178, 6304066, 6580258, 5511131, 6498466
TYPICAL APPLICATIO
Li-Ion to 5V at 1MHz
7.4µH
Li Ion
3.1V TO 4.2V
2.2µF
V_IN
SW
LTC3458L
GND/PGND
V_OUT
ON OFF
SHDN
FB
SYNC
R_T
I_LIM
200k 84.5k
COMP
SS
BURST
0.01µF
0.01µF
133k
V_OUT
5V
10pF
750mA
1M
33k
10pF
324k
22µF
X5R
560pF
3458L TA01a
100
95
90
85
80
75
70
65
60
0.1
Li-Ion to 5V_OUT
1000
4.2V_IN
3.1V_IN
100
3.6V_IN
10
POWER
LOSS
1
1
10
100
LOAD CURRENT (mA)
0.1
1000
3458L TA01b
3458lf
1