LTC3112_15 Datasheet, PDF (1/32 Pages) Linear Technology – 15V, 2.5A Synchronous Buck-Boost DC/DC Converter

Features
n _{Regulated Output with VIN Above, Below or Equal to VOUT}
n _{2.7V to 15V Input Voltage Range}
n _{2.5V to 14V Output Voltage Range}
n _{2.5A Continuous Output Current: VIN ≥ 5V,}
V_OUT = 5V, PWM Mode
n _{Output Current Monitor}
n _{Up to 95% Efficiency}
n _{750kHz Switching Frequency, Synchronizable}
Between 300kHz and 1.5MHz
n _{Internal N-Channel MOSFETs}
n _{Selectable Burst Mode}^® _{Operation, IQ = 50µA}
n _{Shutdown Current < 1µA}
n _{Overvoltage Protection}
n _{Output Disconnect in Shutdown}
n _{Internal Soft-Start}
n _{Small, Thermally Enhanced 16-Lead (4mm × 5mm ×}
0.75mm) DFN and 20-Lead TSSOP Package
Applications
n _{3.3V or 5V from 1, 2 or 3 Li-Ion, Backup Capacitor Stack}
n _{Hand Held Inventory Terminals}
n _{RF Transmitters}
n _{12V Synchronous Boost Converter}
n _{Multiple Power Input Systems}
n _{LED Lighting with Current Regulation}
n _{12V Lead Acid Battery to 12V}
LTC3112
15V, 2.5A Synchronous
Buck-Boost DC/DC
Converter
Description
The LTC^®3112 is a fixed frequency synchronous buck-boost
DC/DC converter with an extended input and output range.
The unique 4-switch, single inductor architecture provides
low noise and seamless operation from input voltages
above, below or equal to the output voltage.
With an input range of 2.7V to 15V, the LTC3112 is well-
suited for a wide variety of single or multiple cell battery,
backup capacitor or wall adapter source applications. Low
R_DS(ON) internal N-Channel MOSFET switches provide
highly efficient operation in applications with higher load
current requirements.
The LTC3112 features selectable PWM or Burst Mode
operation, an easily synchronized oscillator and output
disconnect in shutdown. An output current monitor circuit
allows the load current to be controlled or measured. Other
features include <1µA shutdown current, short circuit
protection, soft-start, current limit and thermal shutdown.
The LTC3112 is offered in both a 16-pin (4mm × 5mm ×
0.75mm) DFN and 20-pin TSSOP packages.
L, LT, LTC, LTM, Linear Technology Burst Mode, LTSpice and the Linear logo are registered
trademarks and No R_SENSE and PowerPath are trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners. Protected by U.S. Patents,
including 5481178.
Typical Application
5V, 750kHz Wide Input Voltage Range Buck-Boost Regulator
4.7µH
0.1µF
2.7V TO 15V
V_IN
BURST PWM
10µF
OFF ON
1µF
SW1
SW2
BST1
BST2
V_IN
V_OUT
V_CC LTC3112 COMP
PWM/SYNC
FB
RUN
I_OUT
GND
OVP
0.1µF
680pF ^33k
22pF
845k
5V/2.5A, V_IN > 5V
V_OUT
47pF
10k
TO ADC
1V PER AMP
47µF
100pF 42.2k
158k
3112 TA01
For more information www.linear.com/LTC3112
Efficiency at 5V_OUT
100
PWM
90
BURST
80
70
60
50
40
30
0.0001 0.001 0.01 0.1
LOAD CURRENT (A)
2.7V_IN
5.0V_IN
12V_IN
1
3112 TA02
3112fc
1