POWER LOSS (W)
LTC3419
Dual Monolithic 600mA
Synchronous Step-Down
Regulator
FEATURES DESCRIPTION
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High Ef ciency Dual Step-Down Outputs: Up to 96%
The LTC 3419 is a dual, 2.25MHz, constant-frequency,
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600mA Current per Channel at V = 3V
synchronous step-down DC/DC converter in a tiny
IN
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Only 35A Quiescent Current During Operation
3mm 3mm DFN package. 100% duty cycle provides
(Both Channels)
low dropout operation, extending battery life in portable
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2.25MHz Constant-Frequency Operation
systems. Low output voltages are supported with the 0.6V
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2.5V to 5.5V Input Voltage Range
feedback reference voltage. Each regulator can supply
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Low Dropout Operation: 100% Duty Cycle
600mA output current.
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No Schottky Diodes Required
The input voltage range is 2.5V to 5.5V, making it ideal
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Internally Compensated for All Ceramic Capacitors
for Li-Ion and USB powered applications. Supply current
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Independent Internal Soft-Start for Each Channel
during operation is only 35A and drops to <1A in
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Available in Fixed Output Versions
shutdown. A user-selectable mode input allows the user
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Current Mode Operation for Excellent Line and Load
to trade off between high ef ciency Burst Mode operation
Transient Response
and pulse-skipping mode.
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0.6V Reference Allows Low Output Voltages
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An internally set 2.25MHz switching frequency allows the
User-Selectable Burst Mode Operation
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use of tiny surface mount inductors and capacitors. Internal
Short-Circuit Protected
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soft-start reduces inrush current during start-up. Both
Ultralow Shutdown Current: I < 1A
Q
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outputs are internally compensated to work with ceramic
Available in Small MSOP or 3mm 3mm DFN-8
output capacitors. The LTC3419 is available in a low pro le
Packages
(0.75mm) 3mm 3mm DFN package. The LTC3419 is also
available in a xed output voltage con guration selected
APPLICATIONS
via internal resistor dividers (see Table 2).
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Cellular Telephones
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
Burst Mode is a registered trademark of Linear Technology Corporation. All other
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Digital Still Cameras
trademarks are the property of their respective owners. Protected by U.S. Patents,
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Wireless and DSL Modems including 5481178, 6127815, 6304066, 6498466, 6580258, 6611131.
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Portable Media Players
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PDAs/Palmtop PCs
TYPICAL APPLICATION Ef ciency and Power Loss
vs Output Current
Dual Monolithic Buck Regulator in 8-Lead 3 3 DFN
100 10
V = 3.6V
IN
90
V
IN
2.5V TO 5.5V
80 1
10F
70
RUN2 V RUN1
IN
MODE
60 0.1
LTC3419
50
3.3H3.3H
V V
OUT2 OUT1
2.5V AT
1.8V AT SW2 SW1
40 0.01
600mA
600mA 22pF 22pF
30
20 0.001
V = 1.2V
V V OUT
FB2 FB1
10 V = 1.8V
118k GND 187k OUT
10F 10F
59k 59k
V = 2.5V
OUT
0 0.0001
0.1 1 10 100 1000
3419 TA01
OUTPUT CURRENT (mA)
3419 TA01b
3419fa
1
EFFICIENCY (%)LTC3419
ABSOLUTE MAXIMUM RATINGS
(Note 1)
Input Supply Voltage (V ) ............................. 0.3 to 6V Peak SW Source and Sink Current (Note 2) .............1.3A
IN
V , V ........................................0.3V to V + 0.3V Operating Junction Temperature Range
FB1 FB2 IN
RUN1, RUN2, MODE ........................0.3V to V + 0.3V (Note 3) .................................................40 to 125C
IN
SW1, SW2 .......................................0.3V to V + 0.3V Junction Temperature (Note 6) ............................. 125C
IN
P-Channel SW Source Current (DC) (Note 2) .......800mA Storage Temperature Range ...................65C to 125C
N-Channel SW Source Current (DC) (Note 2) ......800mA Lead Temperature (Soldering, 10 sec)
MSOP Package ................................................. 300C
PIN CONFIGURATION
TOP VIEW
TOP VIEW
V 1 8 V
FB1 FB2
V 1 10 V
FB1 FB2
RUN1 2 7 RUN2
RUN1 2 9 RUN2
9
MODE 3 8 SW2
MODE SW2
3 6
SW1 4 7 V
IN
SW1 4 5 V
IN GND 5 6 GND
MS PACKAGE
10-LEAD PLASTIC MSOP
DD PACKAGE
T = 125C, = 120C/W
8-LEAD (3mm s 3mm ) PLASTIC DFN JMAX JA
T = 125C, = 40C/W
JMAX JA
EXPOSED PAD (PIN 9) IS GND, MUST BE SOLDERED TO PCB
ORDER INFORMATION
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC3419EDD#PBF LTC3419EDD#TRPBF LCQJ 8-Lead (3mm 3mm) Plastic DFN 40C to 125C
LTC3419EDD-1#PBF LTC3419EDD-1#TRPBF LCWW 8-Lead (3mm 3mm) Plastic DFN 40C to 125C
LTC3419IDD#PBF LTC3419IDD#TRPBF LCQJ 40C to 125C
8-Lead (3mm 3mm) Plastic DFN
LTC3419IDD-1#PBF LTC3419IDD-1#TRPBF LCWW 40C to 125C
8-Lead (3mm 3mm) Plastic DFN
LTC3419EMS#PBF LTC3419EMS#TRPBF LTCQK 10-Lead Plastic MSOP 40C to 125C
LTC3419EMS-1#PBF LTC3419EMS-1#TRPBF LTCWX 10-Lead Plastic MSOP 40C to 125C
LTC3419IMS#PBF LTC3419IMS#TRPBF LTCQK 10-Lead Plastic MSOP 40C to 125C
LTC3419IMS-1#PBF LTC3419IMS-1#TRPBF LTCWX 10-Lead Plastic MSOP 40C to 125C
Consult LTC Marketing for parts speci ed with wider operating temperature ranges. *The temperature grade is identi ed by a label on the shipping container.
Consult LTC Marketing for information on non-standard lead based nish parts.
For more information on lead free part marking, go to: