LT3474EFE#PBF Linear Technology, LT3474EFE#PBF Datasheet
LT3474EFE#PBF
Specifications of LT3474EFE#PBF
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LT3474EFE#PBF Summary of contents
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... Display Backlighting ■ ■ Constant Current Sources L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. True Color PWM is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. Patent Pending TYPICAL APPLICATION Step-Down 1A LED Driver V ...
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... LT3474E, LT3474E-1 ............................ –40°C to 85°C LT3474I, LT3474I-1 ............................ –40°C to 125°C Storage Temperature Range ................... –65°C to 150°C Lead Temperature (Soldering, 10 sec) .................. 300°C ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL LT3474EFE#PBF LT3474EFE#TRPBF LT3474IFE#PBF LT3474IFE#TRPBF LT3474EFE-1#PBF LT3474EFE-1#TRPBF LT3474IFE-1#PBF LT3474IFE-1#TRPBF Consult LTC Marketing for parts specifi ...
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ELECTRICAL CHARACTERISTICS temperature range, otherwise specifi cations are at T PARAMETER Reference Voltage Line Regulation Reference Voltage Load Regulation V Pin Bias Current (Note 4) ADJ Switching Frequency Maximum Duty Cycle Foldback Frequency SHDN Threshold (to Switch) SHDN Pin Current ...
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LT3474/LT3474-1 TYPICAL PERFORMANCE CHARACTERISTICS LED Current vs V ADJ 1000 T = 25°C A 800 600 400 200 0 0.25 0. (V) ADJ 3474 GO3 Current Limit vs Duty Cycle 2.5 2 TYPICAL MINIMUM (85°C) 1.5 ...
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TYPICAL PERFORMANCE CHARACTERISTICS Boost Pin Current 25° 250 500 750 1000 1250 1500 SWITCH CURRENT (mA) 3473 G12 Schottky Reverse Leakage ...
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LT3474/LT3474-1 PIN FUNCTIONS DNC (Pins 1, 16): Do not connect external circuitry to these pins, or tie them to GND. Leave the DNC pins fl oating. OUT (Pin 2): The OUT pin is the input to the current sense resistor. ...
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BLOCK DIAGRAM INT REG SHDN 10 AND UVLO ∑ SLOPE COMP R T OSC FREQUENCY FOLDBACK – REF 11 PWM 14 V ADJ ...
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LT3474/LT3474-1 APPLICATIONS INFORMATION Operation The LT3474 is a constant frequency, current mode regula- tor with an internal power switch capable of generating a constant 1A output. Operation can be best understood by referring to the Block Diagram. If the SHDN ...
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APPLICATIONS INFORMATION The switch driver operates either from V BOOST pin. An external capacitor and internal Schottky diode are used to generate a voltage at the BOOST pin that is higher than the input supply. This allows the driver to ...
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LT3474/LT3474-1 APPLICATIONS INFORMATION Setting the Switching Frequency The LT3474 uses a constant frequency architecture that can be programmed over a 200kHz to 2MHz range with a single external timing resistor from the R The current that fl ows into the ...
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... For details of maximum output current and discontinuous mode operation, see Linear Technology’s Application Note 44. Finally, for duty cycles greater than 50% (V inductance is required to avoid sub-harmonic oscillations. See Application Note 19. ...
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LT3474/LT3474-1 APPLICATIONS INFORMATION To maintain output regulation, this peak current must be less than the LT3474’s switch current limit least 1.6A (1.5A at 125°C) at low duty cycles and LIM decreases linearly to 1.15A (1.08A at ...
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APPLICATIONS INFORMATION A fi nal caution is in order regarding the use of ceramic capacitors at the input. A ceramic input capacitor can combine with stray inductance to form a resonant tank circuit. If power is applied quickly (for example ...
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LT3474/LT3474-1 APPLICATIONS INFORMATION Diode Selection The catch diode (D1 from Figure 1) conducts current only during switch off time. Average forward current in normal operation can be calculated from – V OUT IN OUT I = ...
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APPLICATIONS INFORMATION BOOST and BIAS Pin Considerations The capacitor and internal diode tied to the BOOST pin generate a voltage that is higher than the input voltage. In most cases, a 0.22μF capacitor will work well. Figure 4 shows three ...
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LT3474/LT3474-1 APPLICATIONS INFORMATION To minimize the error from variations in V use resistors with a parallel resistance of less than 4k. Use resistors with a series resistance of 5.11k or greater so as not to exceed the 250μA current limit ...
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APPLICATIONS INFORMATION LED Voltage Range The LT3474 can drive LED voltages from 2.4V to 12V. The LT3474-1 can drive LED voltages from 2.4V to 30V. Be careful not to exceed the ABSMAX rating of the OUT, LED, or BOOST pins ...
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LT3474/LT3474-1 TYPICAL APPLICATIONS Step-Down 1A LED Driver with PWM Dimming 36V C1 V BOOST 2.2μF IN 50V SHDN SW LT3474 R BIAS T REF OUT V PWM R1 ADJ 80.6k V LED C C4 GND 3.3nF ...
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... DIMENSIONS ARE IN 3. DRAWING NOT TO SCALE Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa- tion that the interconnection of its circuits as described herein will not infringe on existing patent rights. FE Package 16-Lead Plastic TSSOP (4 ...
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... Step-Up Regulator with Dual Rail to Rail Current Sense V LT3479 3A, Full Featured DC/DC Converter with Soft-Start and Inrush Current Protection Burst Mode is a registered trademark of Linear Technology Corporation. ThinSOT is a trademark of Linear Technology Corporation. Linear Technology Corporation 20 1630 McCarthy Blvd., Milpitas, CA 95035-7417 ...