Document
FEATURES
n 1.3MHz (LT3460) Switching Frequency n 650kHz (LT3460-1) Switching Frequency n High Output Voltage: Up to 36V n 300mA Integrated Switch (LT3460) n 180mA Integrated Switch (LT3460-1) n Wide Input Range: 2.5V to 16V n Uses Small Surface Mount Components n Low Shutdown Current: <1μA n Low Profile (1mm) SC70 (LT3460 and LT3460-1),
SOT-23 (ThinSOT™) (LT3460) and 2mm × 2mm DFN (LT3460-1) Packages
APPLICATIONS
n Digital Cameras n CCD Bias Supply n XDSL Power Supply n TFT-LCD Bias Supply n Local 5V or 12V Supply n Medical Diagnostic Equipment n Battery Backup
LT3460/LT3460-1
1.3 MHz/650kHz Step-Up DC/DC Converter in SC70,
ThinSOT and DFN DESCRIPTION
The LT®3460/LT3460-1 are general purpose step-up DC/ DC converters. The LT3460/LT3460-1 switch at 1.3MHz/ 650kHz, allowing the use of tiny, low cost and low height capacitors and inductors. The constant frequency results in low, predictable output noise that is easy to filter.
The high voltage switches in the LT3460/LT3460-1 are rated at 38V, making the device ideal for boost converters up to 36V. The LT3460 can generate 12V at up to 70mA from a 5V supply.
The low 1mA quiescent current and 650kHz switching frequency of LT3460-1 make it ideal for lower current applications.
The LT3460 is available in SC70 and SOT-23 packages. The LT3460-1 is available in SC70 and 2mm × 2mm DFN packages.
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners.
TYPICAL APPLICATION
5V to 12V, 70mA Step-Up DC/DC Converter
22μH VIN 5V
4.7μF OFF ON
VIN SW LT3460
SHDN
FB
GND
130k
22pF
VOUT 12V
70mA
1μF 15k
3460 F01
EFFICIENCY (%)
Efficiency
90
85
80
75
70
65
60 0
20 40
60
LOAD CURRENT (mA)
80
3460 F01a
Switching Waveforms
VSW 5V/DIV
IL 100mA/DIV
0.2μs/DIV
3460 F01b
3460fb
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LT3460/LT3460-1
ABSOLUTE MAXIMUM RATINGS (Note 1)
Input Voltage (VIN)....................................................16V SW Voltage ...............................................................38V
FB Voltage...................................................................5V
SHDN Voltage ...........................................................16V
Operating Ambient Temperature Range (Note 2)....................– 40°C to 85°C Maximum Junction Temperature........................... 125°C Storage Temperature Range................... –65°C to 150°C Lead Temperature (Soldering, 10 sec) .................. 300°C
PIN CONFIGURATION
TOP VIEW
SW 1 GND 2
FB 3
5 VIN 4 SHDN
S5 PACKAGE 5-LEAD PLASTIC TSOT-23
TJMAX = 125°C, θJA = 256°C/W IN FREE AIR θJA = 120°C ON BOARD OVER GROUND PLANE
TOP VIEW
FB 1
6 SHDN
NC 2 7 5 NC
SW 3
4 VIN
TOP VIEW
SW 1 GND 2
FB 3
6 VIN 5 GND 4 SHDN
SC6 PACKAGE 6-LEAD PLASTIC SC70
TJMAX = 125°C, θJA = 400°C/W IN FREE AIR θJA = 270°C/W ON BOARD OVER GROUND PLANE
DC PACKAGE 6-LEAD (2mm × 2mm) PLASTIC DFN
TJMAX = 125°C, θJA = 102°C/W EXPOSED PAD (PIN 7) IS GND, MUST BE SOLDERED TO PCB
ORDER INFORMATION
LEAD FREE FINISH
TAPE AND REEL
PART MARKING
PACKAGE DESCRIPTION
LT3460ES5#PBF
LT3460ES5#TRPBF
LTB1
5-Lead Plastic TSOT-23
LT3460ESC6#PBF
LT3460ESC6#TRPBF
LAAF
6-Lead Plastic SC70
LT3460ESC6-1#PBF
LT3460ESC6-1#TRPBF LDJV
6-Lead Plastic SC70
LT3460EDC-1#PBF
LT3460EDC-1#TRPBF LDNB
6-Lead (2mm × 2mm) Plastic DFN
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: http://www.linear.com/leadfree/ For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/
TEMPERATURE RANGE –40°C to 85°C –40°C to 85°C –40°C to 85°C –40°C to 85°C
3460fb
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LT3460/LT3460-1
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C, VIN = 3V, VSHDN = 3V, unless otherwise noted.
LT3460
LT3460-1
PARAMETER
CONDITIONS
MIN TYP MAX MIN TYP MAX UNITS
Minimum Operating Voltage
2.5 2.5
V
Maximum Operating Voltage
16 16 V
Feedback Voltage
1.235 1.255 1.275 1.235 1.255 1.275
l 1.225
1.280 1.225
1.280
V V
Feedback Line Regulation 2.5V < VIN < 16V FB Pin Bias Current
0.015
l5
25 80
0.015
%/V
0 25 80 nA
Supply Current
SHDN = 0V
2.0 3.0 0.1 0.5
1.0 1.5 mA
0.1 0.5
μA
Switching Frequency
1.0 1.3 1.7 0.35 0.65 1.0 MHz
Maximum Duty Cycle
85 90
80 90
%
Switch Current Limit
300 420 600 180 260 380 mA
Switch VCESAT Switch Leakage Current SHDN Voltage High SHDN Voltage Low SHDN Pin Bias Current
ISW = 250mA (LT3460), ISW = 100mA (LT3460-1) VSW = 5V
320 450
220 350
mV
0.01 1
0.01 1
μA
1.5 1.5
V
0.4 0.4 V
40 15 μA
Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect .