LTC3536
1A Low Noise, Buck-Boost
DC/DC Converter
Features
Description
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
VIN ≥ 3V, VOUT = 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 I
Q
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
The LTC®3536 is an extended VIN 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.
n
Applications
n
n
n
n
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 oscillator 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 RSENSE are trademarks of Linear Technology Corporation. All
other trademarks are the property of their respective owners.
Wireless Inventory Terminals
Handheld Medical Instruments
Wireless Locators, Microphones
Supercapacitor Backup Power Supply
Typical Application
Efficiency vs Input Voltage
100
4.7µH
SW2
VOUT
47pF
LTC3536
10µF
PWM BURST
OFF ON
MODE/SYNC FB
SHDN
RT
VC
PGND SGND
VOUT
3.3V
1A FOR VIN ≥ 3V
6.49k
49.9k
1000k
220pF
22µF
90
EFFICIENCY (%)
SW1
VIN
VIN
1.8V TO 5.5V
ILOAD = 200mA
95
85
ILOAD = 1A
80
75
70
65
60
221k
55
3536 TA01a
50
1.5
2
2.5
3 3.5
4 4.5
INPUT VOLTAGE (V)
5
5.5
3536 TA01b
3536fa
1
