LM2743-19AEVAL National Semiconductor, LM2743-19AEVAL Datasheet
LM2743-19AEVAL
Specifications of LM2743-19AEVAL
Related parts for LM2743-19AEVAL
LM2743-19AEVAL Summary of contents
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... Low Voltage N-Channel MOSFET Synchronous Buck Regulator Controller General Description The LM2743 is a high-speed synchronous buck regulator controller with an accurate feedback voltage accuracy of ±2%. It can provide simple down conversion to output volt- ages as low as 0.6V. Though the control sections of the IC are rated for 3 to 6V, the driver sections are designed to ac- cept input supply rails as high as 16V ...
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... Connection Diagram Ordering Information Order Number LM2743MTC LM2743MTCX Pin Descriptions BOOT (Pin 1) - Bootstrap pin. This is the supply rail for the gate drivers. When the high-side MOSFET turns on, the volt- age on this pin should be at least one gate threshold above the regulator input voltage V ...
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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 I SEN All other pins Junction Temperature Storage Temperature 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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Symbol Parameter GATE DRIVE I BOOT Pin Quiescent Current Q-BOOT R High-Side MOSFET Driver Pull-Up HG_UP ON resistance R High-Side MOSFET Driver Pull- HG_DN Down ON resistance R Low-Side MOSFET Driver Pull-Up LG_UP ON resistance R Low-Side MOSFET Driver Pull- ...
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Typical Performance Characteristics Efficiency (V = 1.2V) OUT V = 3.3V 300 kHz CC SW Efficiency (V = 3.3V) OUT 300 kHz CC SW BOOT Pin Current vs Temperature for BOOT Voltage = ...
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BOOT Pin Current vs Temperature for BOOT Voltage = 12V f = 300 kHz, FDS6898A FET, No-Load SW Frequency vs Temperature Switch Waveforms (HG Rising 3. 12nF, ...
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Start-Up (No-Load 3. OUT C = 12nF 300 kHz SS SW Shutdown (Full-Load 3. OUT I = 4A, ...
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Line Transient Response ( 3.3V OUT 300 kHz OUT SW www.national.com = 3V to 9V) Line Transient Response ( 1.2V 20095254 3V ...
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9 www.national.com ...
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... If the master supply voltage was 5V and the LM2743 output voltage was 1.8V, for example, then the value of R plies identical soft-start times would be 150Ω. A timing dia- ...
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... Be- cause the output of the master supply is divided down, in order to track properly the output voltage of the LM2743 must be lower than the voltage of the master supply. In this case, the tracking resistors can be determined based on the following ...
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... V because the drive voltage depends only on V 20095206 Note that the LM2743 can be paired with a low cost linear regulator like the LM78L05 to run from a single input rail be- tween 6.0 and 14V. The 5V output of the linear regulator powers both the V cient drive for logic level MOSFETs ...
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... both high-side and low-side gates will have at least 4.5V of drive. The power dissipation of the gate drive circuitry is di- rectly proportional to gate drive voltage, hence the thermal limits of the LM2743 IC will quickly be reached if this circuit is used with voltages over 5V FIGURE 9 ...
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... The 200 SW enters shutdown mode, and discharges the soft-start capac- itor through a MOSFET switch. The high and low-side MOS- FETs are turned off. The LM2743 remains in this state as long as V sees a logic low (see the Electrical Characteristics ta- SD ble). To assure proper IC start-up the shutdown pin should not be left floating ...
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... R value of the MOSFETs, the minimum input voltage, DS(on) and maximum load. As shown in Figure maximum duty cycles of the LM2743 occurs at 125°C junction temperature vs V (IC control section voltage). Ensure that CC the operating duty cycle is below the curve in condition is not satisfied, the system will be unable to develop the required duty cycle to derive the necessary system power and so the output voltage will fall out of regulation ...
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... The second part is is the gate charge of the the error amplifier, which for the LM2743 MHz op-amp used in the classic inverting configuration. the regulator and control loop components. ...
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... The power stage modulator provides a DC gain A equal to the input voltage divided by the peak-to-peak value of the PWM ramp. This ramp is 1.0VP-P for the LM2743. The inductor and output capacitor create a double pole at fre- quency f , and the capacitor ESR and capacitance create a ...
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... The error amplifier of the LM2743 has a unity-gain bandwidth of 9 MHz. In order to model the effect of this limitation, the open-loop gain can be calculated as: ...
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In practice, a good trade off between phase margin and band- width can be obtained by selecting the closest ±10% capac- itor values above what are suggested for C closest ±10% capacitor value below the suggestion for C and the ...
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OUT P = 0 300 kHz 61. The FDS6898A has a typical turn-on rise time t ...
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... Example Circuits PART PART NUMBER U1 LM2743 Q1 FDS6898A D1 MBR0520LTI L1 DO3316P-472 C 1 16SP100M 6SP220M VJ1206Y104KXXA CC BOOT VJ0805Y332KXXA C3 C VJ0805A123KXAA SS C VJ0805A821KXAA C2 C VJ0805A220KXAA C1 R CRCW08051002F FB2 R CRCW08054991F FB1 R CRCW08051103F FADJ R CRCW08052101F C2 R CRCW08052101F CS R CRCW080510R0F CC R CRCW08055492F C1 R CRCW08051003J PULL-UP FIGURE 17. 3.3V to 1.8V @ 2A, f ...
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... PART PART NUMBER U1 LM2743 Q1 FDS6898A D1 MBR0520LTI L1 DO3316P-682 C 1 16SP100M 10SP56M VJ1206Y104KXXA CC BOOT VJ0805Y182KXXA C3 C VJ0805A123KXAA SS C VJ0805A821KXAA C2 C VJ0805A330KXAA C1 R CRCW08051002F FB2 R CRCW08053161F FB1 R CRCW08051103F FADJ R CRCW08051301F C2 R CRCW08052101F CS R CRCW080510R0F CC R CRCW08053322F C1 R CRCW08051003J PULL-UP www.national.com FIGURE 18 2. 300kHz SW TYPE ...
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... PART PART NUMBER U1 LM2743 Q1 FDS6898A D1 MBR0520LTI L1 DO3316P-332 C 1 16SP100M 6SP220M VJ1206Y104KXXA CC BOOT VJ0805Y222KXXA C3 C VJ0805A123KXAA SS C VJ0805Y332KXXA C2 C VJ0805A820KXAA C1 R CRCW08051002F FB2 R CRCW08052211F FB1 R CRCW08051103F FADJ R CRCW08052611F C2 R CRCW08054121F CS R CRCW080510R0F CC R CRCW08051272F C1 R CRCW08051003J PULL-UP FIGURE 19. 12V to 3. 300kHz SW TYPE ...
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Physical Dimensions www.national.com inches (millimeters) unless otherwise noted TSSOP-14 Pin Package NS Package Number MTC14 24 ...
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Notes 25 www.national.com ...
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