LTC3536_15 Datasheet, PDF (1/28 Pages) Linear Technology – 1A Low Noise, Buck-Boost DC/DC Converter

LTC3536
1A Low Noise, Buck-Boost
DC/DC Converter
Features
n _{Regulated Output with Input Voltage Above, Below}
or Equal to the Output Voltage
n _{1.8V to 5.5V Input and Output Voltage Range}
n _{1A Continuous Output Current for}
V_IN ≥ 3V, V_OUT = 3.3V
n _{±1% Output Voltage Accuracy}
n _{Low Noise Buck-Boost Architecture}
n _{Up to 95% Efficiency}
n _{Programmable Frequency from 300kHz to 2MHz}
n _{Synchronizable Oscillator}
n _{Burst Mode}^® _{Operation: 32µA IQ}
n _{Internal 1ms Soft-Start}
n _{Output Disconnect in Shutdown}
n _{Shutdown Current: 1µA}
n _{Short-Circuit Protection}
n _{Small Thermally Enhanced 12-Pin MSOP}
and 10-Pin (3mm × 3mm) DFN Packages
Applications
n _{Wireless Inventory Terminals}
n _{Handheld Medical Instruments}
n _{Wireless Locators, Microphones}
n _{Supercapacitor Backup Power Supply}
Description
The LTC^®3536 is an extended V_IN range, fixed frequency,
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.
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.
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.
L, LT, LTC, LTM, Burst Mode, LTspice, Linear Technology and the Linear logo are registered
trademarks and PowerPath and No R_SENSE are trademarks of Linear Technology Corporation. All
other trademarks are the property of their respective owners.
Typical Application
V_IN
1.8V TO 5.5V
10µF
4.7µH
PWM BURST
OFF ON
SW1
V_IN
SW2
V_OUT
LTC3536
MODE/SYNC FB
SHDN
RT
VC
PGND SGND
47pF
6.49k
220pF
49.9k
1000k
221k
V_OUT
3.3V
1A FOR V_IN ≥ 3V
22µF
3536 TA01a
Efficiency vs Input Voltage
100
95
I_LOAD = 200mA
90
85
I_LOAD = 1A
80
75
70
65
60
55
50
1.5 2 2.5 3 3.5 4 4.5 5 5.5
INPUT VOLTAGE (V)
3536 TA01b
3536fa
1