POWER LOSS (mW)
LT3580
Boost/Inverting DC/DC
Converter with 2A Switch,
Soft-Start, and Synchronization
FEATURES DESCRIPTION
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2A Internal Power Switch The LT 3580 is a PWM DC/DC converter containing an
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Adjustable Switching Frequency internal 2A, 42V switch. The LT3580 can be configured
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Single Feedback Resistor Sets V as either a boost, SEPIC or inverting converter. Capable
OUT
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Synchronizable to External Clock of generating 12V at 550mA or 12V at 350mA from a
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High Gain SHDN Pin Accepts Slowly Varying 5V input, the LT3580 is ideal for many local power supply
Input Signals designs.
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Wide Input Voltage Range: 2.5V to 32V
The LT3580 has an adjustable oscillator, set by a resistor
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Low V Switch: 300mV at 1.5A (Typical)
CESAT
from the RT pin to ground. Additionally, the LT3580 can
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Integrated Soft-Start Function
be synchronized to an external clock. The free running or
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Easily Configurable as a Boost or Inverting Converter
synchronized switching frequency range of the part can
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User Configurable Undervoltage Lockout (UVLO)
be set between 200kHz and 2.5MHz.
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Tiny 8-Lead 3mm 3mm DFN and 8-Lead MSOP
The LT3580 also features innovative SHDN pin circuitry
Packages
that allows for slowly varying input signals and an adjust-
able undervoltage lockout function.
APPLICATIONS
Additional features such as frequency foldback and
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VFD Bias Supplies
soft-start are integrated. The LT3580 is available in tiny
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TFT-LCD Bias Supplies
3mm 3mm 8-lead DFN and 8-lead MSOP packages.
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GPS Receivers
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
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DSL Modems
Technology Corporation. ThinSOT is a trademark of Linear Technology Corporation. All other
trademarks are the property of their respective owners.
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Local Power Supply
TYPICAL APPLICATION
1.2MHz, 5V to 12V Boost Converter Achieves Over 88% Efficiency Efficiency and Power Loss
95 1200
4.2H
V
OUT
V
IN 90
12V
5V 1000
550mA
85
10F
V SW
IN
80 800
SHDN GND
LT3580 130k
75
RT FB
600
70
VC
SYNC SS
10k
65 400
2.2F 75k 0.1F
1nF
60
200
3580 TA01
55
50 0
0 100 200 300 600
400 500
LOAD CURRENT (mA)
3580 TA01b
3580fg
1
EFFICIENCY (%)LT3580
ABSOLUTE MAXIMUM RATINGS
(Note 1)
V Voltage ................................................. 0.3V to 32V
Operating Junction Temperature Range
IN
SW Voltage ................................................ 0.4V to 42V
LT3580E (Notes 2, 5) .........................40C to 125C
RT Voltage ...................................................0.3V to 5V
LT3580I (Notes 2, 5) ..........................40C to 125C
SS and FB Voltage ....................................0.3V to 2.5V
LT3580H (Notes 2, 5) ........................40C to 150C
VC Voltage ...................................................0.3V to 2V
LT3580MP (Notes 2, 5) ..................... 55C to 125C
SHDN Voltage ............................................ 0.3V to 32V
Storage Temperature Range ..................65C to 150C
SYNC Voltage ............................................ 0.3V to 5.5V
PIN CONFIGURATION
TOP VIEW
TOP VIEW
FB 1 8 SYNC
FB 1 8 SYNC
VC 2 7 SS
VC 2 9 7 SS
9
V 3 GND 6 RT
GND IN
V RT
3 6
IN
5
SW 4 SHDN
SW SHDN
4 5
MS8E PACKAGE
8-LEAD PLASTIC MSOP
DD PACKAGE
= 35C/W TO 40C/W
JA
8-LEAD (3mm 3mms ) PLASTIC DFN
EXPOSED PAD (PIN 9) IS GND, MUST BE SOLDERED TO PCB
T = 125C, = 43C/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
LT3580EDD#PBF LT3580EDD#TRPBF LCXY 8-Lead (3mm 3mm) Plastic DFN 40C to 125C
LT3580IDD#PBF LT3580IDD#TRPBF LCXY 8-Lead (3mm 3mm) Plastic DFN 40C to 125C
LT3580EMS8E#PBF LT3580EMS8E#TRPBF LTDCJ 8-Lead Plastic MSOP 40C to 125C
LT3580IMS8E#PBF LT3580IMS8E#TRPBF LTDCJ 8-Lead Plastic MSOP 40C to 125C
LT3580HMS8E#PBF LT3580HMS8E#TRPBF LTDCJ 8-Lead Plastic MSOP 40C to 150C
LT3580MPMS8E#PBF LT3580MPMS8E#TRPBF LTDCJ 8-Lead Plastic MSOP 55C to 125C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Consult LTC Marketing for information on non-standard lead based finish parts.
For more information on lead free part marking, go to: