LT3480
36V, 2A, 2.4MHz Step-Down
Switching Regulator with
70A Quiescent Current
FEATURES DESCRIPTION
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Wide Input Range:
The LT 3480 is an adjustable frequency (200kHz to
Operation from 3.6V to 36V
2.4MHz) monolithic buck switching regulator that ac-
Over-Voltage Lockout Protects Circuits
cepts input voltages up to 36V (60V maximum). A high
through 60V Transients
efficiency 0.25 switch is included on the die along with
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2A Maximum Output Current
a boost Schottky diode and the necessary oscillator, con-
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Low Ripple Burst Mode Operation
trol, and logic circuitry. Current mode topology is used
70A I at 12V to 3.3V
for fast transient response and good loop stability. Low
Q IN OUT
Output Ripple < 15mV
ripple Burst Mode operation maintains high efficiency at
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Adjustable Switching Frequency: 200kHz to 2.4MHz
low output currents while keeping output ripple below
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Low Shutdown Current: I < 1A
15mV in a typical application. In addition, the LT3480 can
Q
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Integrated Boost Diode
further enhance low output current efficiency by draw -
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Synchronizable Between 250kHz to 2MHz
ing bias current from the output when V is above 3V.
OUT
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Power Good Flag
Shutdown reduces input supply current to less than 1A
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Saturating Switch Design: 0.25 On-Resistance
while a resistor and capacitor on the RUN/SS pin provide a
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0.790V Feedback Reference Voltage
controlled output voltage ramp (soft-start). A power good
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Output Voltage: 0.79V to 20V
flag signals when V reaches 86% of the programmed
OUT
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Soft-Start Capability
output voltage. The LT3480 is available in 10-lead MSOP
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Small 10-Lead Thermally Enhanced MSOP and
and 3mm 3mm DFN packages with exposed pads for
(3mm 3mm) DFN Packages
low thermal resistance.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
Burst Mode is a registered trademark of Linear Technology Corporation. All other
APPLICATIONS
trademarks are the property of their respective owners.
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Automotive Battery Regulation
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Power for Portable Products
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Distributed Supply Regulation
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Industrial Supplies
TYPICAL APPLICATION
3.3V Step-Down Converter Efficiency
V V 100
IN OUT
4.5V TO 36V 3.3V
TRANSIENT 2A
V = 5V
V BD OUT
IN
TO 60V
90
RUN/SS BOOST
OFF ON
V = 3.3V
OUT
0.47F 80
4.7H
14k
V LT3480 SW
C
4.7F
70
RT
470pF
PG
60
316k
40.2k V = 12V
SYNC FB IN
GND
L = 5.6H
F = 800 kHz
100k 22F
50
0 0.5 1.0 1.5 2
LOAD CURRENT (A)
3480 TA01
3480 TA01b
3480fe
1
For more information www.linear.com/LT3480
EFFICIENCY (%)LT3480
(Note 1)
ABSOLUTE MAXIMUM RATINGS
V , RUN/SS Voltage (Note 5) ...................................60V Storage Temperature Range ................... 65C to 150C
IN
BOOST Pin Voltage ...................................................56V Lead Temperature (Soldering, 10 sec)
BOOST Pin Above SW Pin .........................................30V (MSE Only) ....................................................... 300C
FB, RT, V Voltage .......................................................5V
C
PG, BD, SYNC Voltage ..............................................30V
Operating Junction Temperature Range (Note 2)
LT3480E ............................................. 40C to 125C
LT3480I .............................................. 40C to 125C
LT3480H ............................................ 40C to 150C
LT3480MP.......................................... 55C to 150C
PIN CONFIGURATION
TOP VIEW
TOP VIEW
BD 10 RT
1
BD 1 10 RT
BOOST 2 9 V
C BOOST 2 9 V
C
SW 3 11 8 FB
11
SW 3 8 FB
V 4 7 PG
IN
V 4 7 PG
IN
RUN/SS 5 6 SYNC
RUN/SS 5 6 SYNC
MSE PACKAGE
10-LEAD PLASTIC MSOP
DD PACKAGE
= 45C/W, = 10C/W
JA JC
10-LEAD (3mm 3mm) PLASTIC DFN
EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB
= 45C/W, = 10C/W
JA JC
EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB
ORDER INFORMATION
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LT3480EDD#PBF LT3480EDD#TRPBF LCTP 10-Lead (3mm 3mm) Plastic DFN 40C to 125C
LT3480IDD#PBF LT3480IDD#TRPBF LCTP 40C to 125C
10-Lead (3mm 3mm) Plastic DFN
LT3480EMSE#PBF LT3480EMSE#TRPBF LTCTM 10-Lead Plastic MSOP 40C to 125C
LT3480IMSE#PBF LT3480IMSE#TRPBF LTCTM 10-Lead Plastic MSOP 40C to 125C
LT3480HMSE#PBF LT3480HMSE#TRPBF LTCTM 10-Lead Plastic MSOP 40C to 150C
LT3480MPMSE#PBF LT3480MPMSE#TRPBF LTCTM 10-Lead Plastic MSOP 55C to 150C
LEAD BASED FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LT3480EDD LT3480EDD#TR LCTP 40C to 125C
10-Lead (3mm 3mm) Plastic DFN
LT3480IDD LT3480IDD#TR LCTP 10-Lead (3mm 3mm) Plastic DFN 40C to 125C
LT3480EMSE LT3480EMSE#TR LTCTM 10-Lead Plastic MSOP 40C to 125C
LT3480IMSE LT3480IMSE#TR LTCTM 10-Lead Plastic MSOP 40C to 125C
LT3480HMSE LT3480HMSE#TR LTCTM 10-Lead Plastic MSOP 40C to 150C
LT3480MPMSE LT3480MPMSE#TR LTCTM 10-Lead Plastic MSOP 55C to 150C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
For more information on lead free part marking, go to: