LTC3536
1A Low Noise, Buck-Boost
DC/DC Converter
FeaTures
DescripTion
The LTC®3536 is an extended V range, fixed frequency,
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Regulated Output with Input Voltage Above, Below
IN
or Equal to the Output Voltage
synchronous buck-boost DC/DC converter that operates
from input voltages above, below or equal to the regulated
output voltage. The topology incorporated in the LTC3536
provides low noise operation, making it ideal for RF and
precision measurement applications.
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1.8V to 5.5V Input and Output Voltage Range
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1A Continuous Output Current for
V ≥ 3V, V
= 3.3V
IN
OUT
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1ꢀ Output Voltage Accuracy
Low Noise Buck-Boost Architecture
Up to 95% Efficiency
The device can produce up to 1A of continuous output
current, and it includes two N-channel and two P-channel
MOSFET switches. Switching frequencies up to 2MHz can
be programmed with an external resistor and the oscilla-
tor can be synchronized to an external clock. Quiescent
current is only 32µA in Burst Mode operation, maximizing
battery life in portable applications. Burst Mode operation
is user controlled and improves efficiency at light loads.
Programmable Frequency from 300kHz to 2MHz
Synchronizable Oscillator
Burst Mode® Operation: 32µA I
Q
Internal 1ms Soft-Start
Output Disconnect in Shutdown
Shutdown Current: 1µA
Short-Circuit Protection
Small Thermally Enhanced 12-Pin MSOP
and 10-Pin (3mm × 3mm) DFN Packages
Other features include a 1µA shutdown current, internal
soft-start, overtemperature protection and current limit.
The LTC3536 is available in 12-pin thermally enhanced
MSOP and 10-pin (3mm × 3mm) DFN packages.
applicaTions
L, LT, LTC, LTM, Burst Mode, LTspice, Linear Technology and the Linear logo are registered
trademarks and PowerPath and No R
are trademarks of Linear Technology Corporation. All
SENSE
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Wireless Inventory Terminals
other trademarks are the property of their respective owners.
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Handheld Medical Instruments
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Wireless Locators, Microphones
Supercapacitor Backup Power Supply
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Typical applicaTion
Efficiency vs Input Voltage
100
95
90
85
80
75
70
65
60
55
50
I
= 200mA
LOAD
4.7µH
SW1
SW2
V
OUT
3.3V
V
IN
I
= 1A
V
V
LOAD
IN
OUT
1.8V TO 5.5V
47pF
1A FOR V ≥ 3V
IN
LTC3536
6.49k
1000k
221k
MODE/SYNC
SHDN
PWM BURST
OFF ON
FB
220pF
10µF
22µF
49.9k
RT
VC
PGND SGND
3536 TA01a
1.5
3.5
INPUT VOLTAGE (V)
4.5
5
2
2.5
3
4
5.5
3536 TA01b
3536fa
1