LTC3458
1.4A, 1.5MHz Synchronous
Step-Up DC/DC Converter
with Output Disconnect
DESCRIPTIO
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FEATURES
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High Efficiency: Up to 93%
Inrush Current Limiting and Output Disconnect
Programmable Output Voltages up to 7.5V
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
700mA at 7V from 5V Input
0.3Ω N-Channel and 0.4Ω P-Channel 1.4A Switches
at 5VOUT
Ultralow Quiescent Currents: 15μA Sleep, <1μA in
Shutdown
3mm × 4mm Thermally Enhanced DFN Package
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APPLICATIO S
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Point-of-Load Regulators
USB VBUS Power
LCD Bias
OLED Displays
Quiescent current is only 15μA during Burst Mode operation maximizing battery life in portable applications. The
Burst Mode current threshold, peak current limit, and softstart are externally programmable. Other features include
<1μA shutdown current, antiringing control, and thermal
limit. The LTC3458 is available in a low profile (0.75mm),
3mm × 4mm 12-pin DFN package.
, 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.
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The LTC®3458 is a high efficiency, current mode, fixed
frequency, step up DC/DC converter with true output
disconnect and inrush current limiting. The LTC3458 is
rated for a 7.5V output and includes a 0.3Ω N-channel
MOSFET switch and a 0.4Ω P-channel MOSFET synchronous rectifier. The LTC3458 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 synchronized to an external clock.
TYPICAL APPLICATIO
USB to 7V at 1MHz
COEV
10μH
DQ7545
USB to 7VOUT
1000
100
SW
VIN
95
LTC3458
2.2μF
VOUT
10pF
SHDN
SYNC
ON OFF
FB
COMP
124k
4.35VIN
10
85
POWER LOSS
80
33k
SS
0.01μF
ILIM
90
316k
0.01μF
RT
200k
1.5M
5.25VIN
75
22μF
X5R
10pF
BURST
133k
POWER LOSS (mW)
GND/PGND
VOUT
7V
500mA
EFFICIENCY
USB
4.35V to 5.25V
560pF
70
0.1
1
10
100
LOAD CURRENT (mA)
0.1
1000
3458 TA01b
3458 TA01a
3458fa
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