LTC3617
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Features
Description
TheLTC®3617isahighefficiencymonolithicsynchronous
buckregulatorutilizingacurrentmode,constantfrequency
architecture. It operates from an input voltage range of
2.25V to 5.5V and provides a regulated output voltage
equal to 0.5 • VDDQIN while sourcing and sinking up to
6A of load current. An internal amplifier provides a VTTR
output voltage equal to 0.5 • VDDQIN with an output cur-
rent capability of 1ꢀmA.
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6A Output Current
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2.25V to 5.5V Input Voltage Range
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±±10V Output Voltage Accuracy
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Opti0ized for Low Output Voltages Down to 1.5V
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High Efficiency
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Integrated Buffer for VTTR = VDDQIN • 0.5
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Shutdown Current: <1µA
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Adjustable Switching Frequency: Up to 4MHz
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Optional Internal Compensation
The operating frequency is externally programmable up to
4MHz, allowing the use of small surface mount inductors.
For switching-noise-sensitive applications, the LTC3617
can be synchronized to an external clock up to 4MHz.
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Internal Soft-Start
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Power Good Status Output
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Input Overvoltage Protected
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Thermally Enhanced 24-Pin 3mm × 5mm
ForcedcontinuousmodeoperationintheLTC3617reduces
noise and RF interference. Adjustable external compensa-
tion allows the transient response to be optimized over a
wide range of loads and output capacitors.
QFN Package
applications
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DDR Termination
The internal synchronous switch increases efficiency and
eliminatestheneedforanexternalcatchdiode,minimizing
external component count and board space. The LTC3617
is offered in a leadless 24-pin 3mm × 5mm thermally
enhanced QFN package.
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Supports DDR, DDR2 and DDR3 Standards
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Tracking Supplies
L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks
of Linear Technology Corporation. All other trademarks are the property of their respective
owners. Protected by U.S. Patents, including 6580258, 5481178, 6498466, 6611131.
Efficiency and Power Loss
vs Load Current
typical application
100
90
80
70
60
50
40
30
20
10
0
10
V
IN
2.5V
22µF
×4
SV
PV
IN
IN
V
REF
RUN
VDDQIN
RT
VTTR
1.25V
10ꢀm
1
0.1µF
0.15µH
VTT
1.25V
6m
LTC3617
SW
PGOOD
ITH
SGND
PGND
47µF
×2
0.1
0.01
SYNC
V
FB
3617 Tm01a
0.1
1
10
LOAD CURRENT (A)
3617 TA01b
3617fa
1