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LM21215AMHE-1 Datasheet(PDF) 17 Page - Texas Instruments |
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LM21215AMHE-1 Datasheet(HTML) 17 Page - Texas Instruments |
17 / 38 page ![]() FB PGOOD VIN LM21215A-1 VOUT AGND COMP PVIN SYNC SW EN CIN3 LF RC1 CC1 CC2 CC3 RFB1 RFB2 RC2 PGND AVIN CF 1 11Å16 3 4 17 19 18 20 8,9,10 5,6,7 RF SS/TRK CSS 2 CIN2 CIN1 VIN RPGOOD CO1 CO2 CO3 OPEN PGOOD LM21215A www.ti.com SNOSB87C – MARCH 2011 – REVISED JANUARY 2016 8 Application and Implementation NOTE Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality. 8.1 Application Information The LM21215A is a synchronous buck DC/DC converter with a maximum output current of 15 A. The following design procedure assists with component selection for the LM21215A. Alternately, the WEBENCH® Design Tool is available to generate a complete design. With access to a comprehensive component database, this tool uses an iterative design procedure to create an optimized design, allowing the user to experiment with various design options. As well as numerous LM21215 reference designs populated in the TI Designs reference design library, the LM21215A Quickstart Design Calculator is also available as a free download. 8.2 Typical Application 8.2.1 Typical Application 1 The schematic diagram of a 15-A regulator is given in Figure 28. The target full-load efficiency in this example is 89% at an output voltage of 1.2 V and nominal input voltage of 5 V. The free-running switching frequency (with the SYNC pin open circuit) is 500 kHz. In terms of control loop performance, the target loop crossover frequency is 100 kHz with a phase margin in excess of 50°. Figure 28. Typical Application Schematic 1 8.2.1.1 Design Requirements An example of the step-by-step procedure to generate power stage and compensation component values using the typical application setup of Figure 28) is given in Table 1. The relevant design specifications are given in Table 1. Here, fcrossover is the desired loop crossover frequency, which generally is less than one-fifth of the switching frequency, and ΔVOUT(pk-pk) is the peak-to-peak output voltage ripple. Copyright © 2011–2016, Texas Instruments Incorporated Submit Documentation Feedback 17 Product Folder Links: LM21215A |
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