LM2743MTC National Semiconductor, LM2743MTC Datasheet
LM2743MTC
Specifications of LM2743MTC
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LM2743MTC Summary of contents
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... Both high-side and low-side MOS- FETs are the lower cost N-Channel type, and the IC can accept a bootstrap structure to saturate the high-side MOS- FET for highest efficiency. Typical Application © 2004 National Semiconductor Corporation Features n MOSFET input voltage ( input voltage (V n Output voltage adjustable down to 0.6V ...
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Connection Diagram Pin Description BOOT (Pin 1) - Supply rail for the N-channel MOSFET gate drive. The voltage should be at least one gate threshold (V ) above the regulator input voltage (V GS(th) turn on the high-side FET. LG ...
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... Absolute Maximum Ratings If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications BOOT Voltage All other pins Junction Temperature Storage Temperature Soldering Information Electrical Characteristics V = 3.3V unless otherwise indicated. Typicals and limits appearing in plain type apply for T CC boldface type apply over full Operating Temperature Range ...
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Electrical Characteristics V = 3.3V unless otherwise indicated. Typicals and limits appearing in plain type apply for T CC boldface type apply over full Operating Temperature Range. Datasheet min/max specification limits are guaranteed by design, test, or statistical analysis. Symbol ...
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Typical Performance Characteristics Efficiency (V = 1.2V) OUT V = 3.3V 300kHz CC SW Efficiency (V = 3.3V) OUT 300kHz Operating Current plus BOOT Current vs Frequency CC FDS689A FET ...
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Typical Performance Characteristics BOOT Pin Current vs Temperature for BOOT Voltage = 300kHz, FDS689A FET, No-Load SW Internal Reference Voltage vs Temperature Frequency vs Temperature www.national.com (Continued) BOOT Pin Current vs Temperature for BOOT Voltage = 12V ...
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Typical Performance Characteristics Switch Waveforms (HG Rising 3.3V 5V OUT 12nF, F OUT SS SW Start-Up (No-Load 3.3V 5V OUT I ...
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Typical Performance Characteristics Load Transient Response ( 3.3V 5V 12nF 300kHz SS SW Line Transient Response ( 3.3V OUT 300kHz ...
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Block Diagram Application Information THEORY OF OPERATION The LM2743 is a voltage-mode, high-speed synchronous buck regulator with a PWM control scheme designed for use in set-top boxes, thin clients, DSL/Cable modems, and other applications that require high efficiency ...
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Application Information FIGURE 1. Start-Up Behavior NORMAL OPERATION While in normal operation mode, the LM2743 regulates the output voltage by controlling the duty cycle of the high side and low side FETs. The equation governing output voltage is: The PWM ...
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Application Information *(R /(R FB OUT2 FB2 FB1 Since =0.6V, then SS FB Tracking Equation The total value of the track resistor divider (Figure 3 should be set below 10kΩ for ...
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Application Information FIGURE 8. Timing Behavior of Case 3 If the tracking through SS/TRACK pin is not used, a capaci- tor to ground is needed to limit the inrush current. MOSFET GATE DRIVERS The LM2743 has two gate drivers designed ...
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Application Information FIGURE 11. Bootstrap Configuration input voltage of 3V both, the high and low, side FETs are driven with about 4.5V. The decision on which configuration to use depends on the desired output current and operating ...
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Application Information Input Capacitor The input capacitors in a Buck switching converter are sub- jected to high stress due to the input current square wave- form. Hence input capacitors are selected for their ripple current capability and their ability to ...
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Application Information In this example, in order to maintain a 2% peak-to-peak output voltage ripple and a 40% peak-to-peak inductor cur- rent ripple, the required maximum ESR is 15mΩ.The Sanyo 4SP560M aluminum electrolytic capacitor will give an equivalent ESR of ...
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Example Circuits PART PART NUMBER U LM2743 1 Q FDS6898A 1 D MBR0520LTI 1 L DO3316P-472 16SP100M 6SP220M VJ1206Y104KXXA CC BOOT VJ805Y332KXXA C3 ...
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Example Circuits (Continued) PART PART NUMBER U LM2743 1 Q FDS6898A 1 D MBR0520LTI 1 L DO3316P-682 16SP100M 10SP56M VJ1206Y104KXXA CC BOOT VJ0805A182KXAA ...
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Example Circuits (Continued) PART PART NUMBER U LM2743 1 Q FDS6898A 1 D MBR0520LTI 1 L DO3316P-332 16SP100M 6SP220M VJ1206Y104KXXA CC BOOT VJ805Y222KXXA ...
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Evaluation Board Schematic PART PART NUMBER U LM2743 1 Q FDS6898A 1 D MBR0520LTI 1 L DO3316P-222 1 J NOT USED 1 C12 20SP120M C16 4SP560M C4,C5,C10, VJ1206Y104KXXA C13,C19 C11 VJ805Y332KXXA C7 VJ0805Y123KXXA FIGURE 15. 3.3V to 1.2V @ 4A, ...
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Evaluation Board Schematic PART PART NUMBER C8 VJ1206Y122KXXA C9 VJ0805A270KXAA C1, C2, C3, C6, NOT USED C14, C15, C17, C18, C20 R6 CRCW08051002F R7 CRCW08051002F R2 CRCW08051103F R5 CRCW08052551F R4 CRCW08051501F R1 CRCW080510R0F R3 CRCW08054022F R11 CRCW08050R00F R8 CRCW08051003J PCB ...
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PCB Layout for the Evaluation Board (Continued) Top Copper Bottom Silkscreen 21 20095237 20095238 www.national.com ...
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PCB Layout for the Evaluation Board www.national.com (Continued) Bottom Copper 22 20095239 ...
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... BANNED SUBSTANCE COMPLIANCE National Semiconductor certifies that the products and packing materials meet the provisions of the Customer Products Stewardship Specification (CSP-9-111C2) and the Banned Substances and Materials of Interest Specification (CSP-9-111S2) and contain no ‘‘Banned Substances’’ as defined in CSP-9-111S2. ...