LTC3415 Datasheet, PDF (1/28 Pages) Linear Technology – 7A, PolyPhase Synchronous Step-Down Regulator

FEATURES
n _{High Efficiency: Up to 96%}
n _{7A Output Current at VIN = 3V}
n _{Adjustable Frequency: 1.5MHz Nominal}
n _{PolyPhase Operation (Up to 12 Phases)}
n _{Spread Spectrum Frequency Modulation}
n _{Output Tracking and Margining}
n _{±1% Reference Accuracy}
n _{2.5V to 5.5V VIN Range}
n _{Phase Lockable from 0.75MHz to 2.25MHz}
n _{Selectable Burst Mode}^® _Operation
n _{Low Dropout Operation: 100% Duty Cycle}
n _{Low Quiescent Current: 450μA}
n _{Current Mode Operation for Excellent Line and Load}
Transient Response
n _{Shutdown Mode Draws Only 0.2μA Supply Current}
n _{Available in 38-Pin (5mm × 7mm) QFN Package}
APPLICATIONS
n _{Point of Load Power Supply}
n _{Portable Instruments}
n _{Distributed Power Systems}
n _{Battery-Powered Equipment}
LTC3415
7A, PolyPhase
Synchronous Step-Down
Regulator
DESCRIPTION
The LTC^®3415 is a high efficiency, monolithic synchronous
buck regulator using a phase lockable constant frequency,
current mode architecture. PolyPhase^® operation allows
multiple LTC3415s to run out of phase while using mini-
mal input and output capacitance. The operating supply
range is from 5.5V down to 2.5V, making it suitable for
single Lithium-Ion battery as well as point of load power
supply applications. Burst Mode operation provides high
efficiency at low load currents. 100% duty cycle provides
low dropout operation that extends operating time in bat-
tery-operated systems.
The operating frequency is internally set at 1.5MHz, al-
lowing the use of small surface mount inductors. For
switching-noise sensitive applications, it can be externally
synchronized from 0.75MHz to 2.25MHz. The PHMODE
pin allows user control of the phase of the outgoing clock
signal. The current sense comparator is factory trimmed
for accurate output current sharing. Burst Mode operation
is inhibited during synchronization or when the MODE pin
is pulled low to reduce noise and RF interference.
, LT, LTC, LTM, Burst Mode and PolyPhase are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
Protected by U.S. Patents, including 5481178, 6580258, 6304066, 6127815, 6498466,
6611131.
TYPICAL APPLICATION
V_IN, 2.5V to 5.5V
CLKIN ^SVIN
PV_{IN SW}
CLKOUT
SW
PHMODE
SW
PLLLPF
SW
RUN
LTC3415
SW
60k
TRACK
FB
MODE
PGOOD
I_TH
120k
SGND
PGND
22μF
x3
0.2μH
V_OUT
1.8V
47μF
x3
3415 TA01
Figure 1. High Efficiency Step-Down Converter
Efficiency and Power Loss
100
90
80
70
60
50
40
30
20
10
0
0.01
10
EFFICIENCY
1
0.1
POWER LOSS
0.1
1
LOAD CURRENT (A)
0.01
2.5V
3.3V
5V _0.001
10
3415 TA01B
3415fa
1