POWER LOSS (W)
LTC3417A
Dual Synchronous
1.5A/1A 4MHz Step-Down
DC/DC Regulator
Fea T Descrip T
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High Efficiency: Up to 95% The LTC 3417A is a dual constant frequency, synchronous
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1.5A/1A Guaranteed Minimum Output Current step-down DC/DC converter. Intended for medium power
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Synchronizable to External Clock applications, it operates from a 2.25V to 5.5V input volt-
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No Schottky Diodes Required age range and has a constant programmable switching
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Programmable Frequency Operation: 1.5MHz or frequency, allowing the use of tiny, low cost capacitors
Adjustable From 0.6MHz to 4MHz and inductors 2mm or less in height. Each output voltage
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Low R Internal Switches is adjustable from 0.8V to 5V. Internal, synchronous, low
DS(ON)
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Short-Circuit Protected R power switches provide high efficiency without
DS(ON)
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V : 2.25V to 5.5V the need for external Schottky diodes.
IN
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Current Mode Operation for Excellent Line and Load
A user selectable mode input allows the user to trade
Transient Response
off ripple voltage for light load efficiency. Burst Mode
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125A Quiescent Current in Sleep Mode
operation provides high efficiency at light loads, while
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Ultralow Shutdown Current: I < 1A
Q
Pulse Skip mode provides low ripple noise at light loads.
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Low Dropout Operation: 100% Duty Cycle
A phase mode pin allows the second channel to operate
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Power Good Output
in-phase or 180 out-of-phase with respect to channel 1.
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Phase Pin Selects 2nd Channel Phase Relationship
Out-of-phase operation produces lower RMS current on V
IN
with Respect to 1st Channel
and thus a lower RMS derating on the input capacitor.
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Internal Soft-Start with Individual Run Pin Control
n To further maximize battery life, the P-channel MOSFETs
Available in Small Thermally Enhanced
are turned on continuously in dropout (100% duty cycle)
(5mm 3mm) DFN and 20-Lead TSSOP Packages
and both channels draw a total quiescent current of only
a T
125A. In shutdown, the device draws <1A.
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GPS/Navigation
L, LT, LTC, LTM and Burst Mode are registered trademarks and Hot Swap and ThinSOT are
trademarks of Linear Technology Corporation. All other trademarks are the property of their
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Digital Cameras
respective owners. Protected by U.S. Patents including 5481178, 6580258, 6304066, 6127815,
6498466, 6611131, 6144194.
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PC Cards
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Wireless and DSL Modems
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General Purpose Point of Load DC/DC
OUT2 Efficiency
Typical a T
(Burst Mode Operation)
V
IN
2.5V TO 5.5V 100 10
REFER TO FIGURE 4
10F
V
IN
95
EFFICIENCY
FREQ 1
1.5H 2.2H
V V
OUT1 OUT2
1.8V SW1 SW2 2.5V
22pF 22pF 90
1.5A 1A
RUN2
V RUN1 V 0.1
IN IN
LTC3417A
85
511k 866k
V
V FB2 0.01
FB1
80 POWER LOSS
47F 412k
412k 22F
I
I TH2
TH1 0.001
75
V = 3.6V
IN
5.9k 2.87k
V = 2.5V
GND
OUT
FREQ = 1MHz
0.0001
2200pF 6800pF 70
0.001 0.01 0.1 1
3417 TA01
LOAD CURRENT (A)
3417 TA01a
3417afc
1
EFFICIENCY (%)
ion pplica
ions pplica
ion uresLTC3417A
a Te Maxi Mu M r a T (Note 1)
V , V Voltages ...................................... 0.3V to 6V PGOOD Voltage ........................................... 0.3V to 6V
IN1 IN2
SYNC/MODE, SW1, SW2, RUN1, Operating Ambient Temperature Range
RUN2, V , V , PHASE, FREQ, (Note 2) ..................................................40C to 85C
FB1 FB2
I , I Voltages............... 0.3V to (V /V + 0.3V) Junction Temperature (Notes 7, 8) ...................... 125C
TH1 TH2 IN1 IN2
V V , V V .......................................... 0.3V Storage Temperature Range ...................65C to 125C
IN1 IN2 IN2 IN1
p in c F T
TOP VIEW
TOP VIEW
GNDD 1 20 GNDD
RUN1 2 19 PGND1
RUN1 1 16 PGND1
V 3 18 SW1
V 2 15 SW1 IN1
IN1
I 4 17 PHASE
I 3 14 PHASE TH1
TH1
V 5 16 GNDA
V 4 13 GNDA FB1
FB1
21
17
V 6 15 FREQ
V 5 12 FREQ FB2
FB2
I 7 14 PGOOD
I 6 11 PGOOD TH2
TH2
RUN2 8 13 SW2
RUN2 7 10 SW2
V 9 12 SYNC/MODE
V 8 9 SYNC/MODE IN2
IN2
PGND2 10 11 PGND2
DHC PACKAGE
16-LEAD (3mm 5mm) PLASTIC DFN
FE PACKAGE
20-LEAD PLASTIC TSSOP
T = 125C, = 43C/W
JMAX JA
EXPOSED PAD (PIN 17) IS PGND2/GNDD, MUST BE SOLDERED TO PCB
T = 125C, = 38C/W
JMAX JA
EXPOSED PAD (PIN 21) IS PGND2/GNDD, MUST BE SOLDERED TO PCB
Der in F Ma T
LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC3417AEDHC#PBF LTC3417AEDHC#TRPBF 3417A 16-Lead (3mm 3mm) Plastic DFN 40C to 85C
LTC3417AEFE#PBF LTC3417AEFE#TRPBF LTC3417AEFE 20-Lead Plastic TSSOP 40C to 85C
LTC3417AIFE#PBF LTC3417AIFE#TRPBF LTC3417AIFE 20-Lead Plastic TSSOP 40C to 85C
Consult LTC Marketing for parts specified with wider operating temperature ranges.
Consult LTC Marketing for information on non-standard lead based finish parts.
For more information on lead free part marking, go to: