LMZ12001EXT,LMZ12002EXT,LMZ12003EXT, LMZ14201EXT,LMZ14202EXT,LMZ14203EXT Application Note 2084 LMZ1420xEXT / LMZ1200xEXT Evaluation Board Literature Number: SNVA456 National Semiconductor Application Note 2084 Alan Martin August 16, 2010 Introduction Board Specifications The LMZ1420xEXT and LMZ1200xEXT SIMPLE SWITCHER(R) power modules are easy-to-use DC-DC solution capable of driving up to a 3A load with exceptional power conversion efficiency, output voltage accuracy, line and load regulation. They are available in an innovative package that enhances thermal performance and allows for hand or machine soldering. The LMZ14203EXT/2EXT/1EXT can accept an input voltage rail between 6V and 42V and the LMZ12003EXT/2EXT/1EXT can accept an input voltage rail between 4.5V and 20V. The devices can deliver an adjustable and highly accurate output voltage as low as 0.8V and as high as 6V. The control structure is constant on-time with input voltage feed forward. This creates a nearly constant switching frequency across the input voltage range. The control loop operates well with low ESR output capacitors such as ceramics. An output feed-forward capacitor across the upper feedback resistor trims for optimum transient response. The precision enable input allows for programmable UVLO of the input supply. The external soft-start capacitor facilitates controlled startup output rise time. The LMZ1420xEXT and LMZ1200xEXT family is a reliable and robust solution with the following features: lossless cycle-by-cycle valley current limit to protect for over current or short-circuit fault, thermal shutdown, input under-voltage lock-out, and will start up into a pre-biased output. The LMZ1420xEXT and LMZ1200xEXT families are shock and vibration certified and rated for operation down to -55C. * * * * * * * * * LMZ1420xEXT VIN = 6V to 42V LMZ1420xEXT enable UVLO = 8V LMZ1420xEXT VOUT = 3.3V LMZ1200xEXT VIN = 4.5V to 20V LMZ1200xEXT enable UVLO = 4.5V LMZ1200xEXT VOUT = 1.8V Operates at full load up to 80C ambient at 12V input JA = 20C / W, JC = 1.9C / W Designed on four layers, all four layers are 1 oz. copper weight * The two internal ground planes are identical * Measures 1.705 in. x 3.03 in. (4.33 cm x 7.7cm) and is 62mil (.062") thick of FR4 laminate material For additional circuit modifications refer to the Design Consideration section of the LMZ1420xEXT or LMZ1200xEXT data sheet. For negative output voltage connections see AN-2027. Additional Footprints Additional component mounting pads are available to experiment with alternative Cin and Cout combinations or a zener clamp on the enable input. See Figure 6 for corresponding schematic locations. AN-2084 30131501 FIGURE 1. Evaluation Board Schematic (LMZ1200xEXT 1.8V application values shown in parentheses) (c) 2010 National Semiconductor Corporation 301315 LMZ1420xEXT / LMZ1200xEXT Evaluation Board LMZ1420xEXT / LMZ1200xEXT Evaluation Board www.national.com AN-2084 TABLE 1. LMZ1420xEXT Bill of Materials, VIN = 8V to 42V, VOUT = 3.3V, IOUT (MAX) = 3A / 2A / 1A Designator Description Case Size Manufacturer Manufacturer P/N Quantity U1 SIMPLE SWITCHER(R) TO-PMOD-7 National Semiconductor LMZ14203EXTTZ or LMZ14202EXTTZ or LMZ14201EXTTZ 1 CIN4, CO1 1 F, X7R, 50V 1206 Taiyo Yuden UMK316B7105KL-T 2 CIN2 10 F, X5R, 50V 1210 Taiyo Yuden UMK325BJ106MM-T 1 CO2 100 F, X5R, 6.3V 1210 Taiyo Yuden JMK325BJ107MM-T 1 CSS, CFF 0.022 F, X7R, 100V 0805 AVX 08051C223JAT2A 2 RENB 11.8k 0805 Panasonic ERJ-6ENF1182V 1 RENT 68.1 k 0805 Panasonic ERJ-6ENF6812V 1 RFBT 3.32 k 0805 Vishay-Dale CRCW08053K32FKEA 1 RFBB 1.07 k 0805 Panasonic CRCW080534K8FKEA 1 RON 61.9 k 0805 Panasonic ERJ-6ENF6192V 1 TABLE 2. LMZ1200xEXT Bill of Materials, VIN = 4.5 to 20V, VOUT = 1.8V, IOUT (MAX) = 3A / 2A / 1A Designator Description Case Size Manufacturer Manufacturer P/N Quantity U1 SIMPLE SWITCHER(R) TO-PMOD-7 National Semiconductor LMZ12003EXTTZ or LMZ12002EXTTZ or LMZ12001EXTTZ 1 CIN4, CO1 1 F, X7R, 50V 1206 Taiyo Yuden UMK316B7105KL-T 2 CIN2 10 F, X5R, 50V 1210 Taiyo Yuden UMK325BJ106MM-T 1 CO2 100 F, X5R, 6.3V 1210 Taiyo Yuden JMK325BJ107MM-T 1 CSS, CFF 0.022 F, X7R, 100V 0805 AVX 08051C223JAT2A 2 RENB 11.8k 0805 Panasonic ERJ-6ENF1182V 1 RENT 32.4K 0805 Panasonic ERJ-6ENF3242V 1 RFBT 1.87 k 0805 Vishay-Dale CRCW08051K87FKEA 1 RFBB 1.50 k 0805 Panasonic CRCW08051K50FKEA 1 RON 32.4K 0805 Panasonic ERJ-6ENF3242V 1 Performance Characteristics LMZ14203EXT Load and Line Regulation LMZ12003EXT Load and Line Regulation 30131504 30131505 www.national.com 2 AN-2084 LMZ14203EXT Efficiency LMZ12003EXT Efficiency 30131502 30131503 LMZ14202EXT Efficiency LMZ12002EXT Efficiency 30131520 30131521 LMZ14201EXT Efficiency LMZ12001EXT Efficiency 30131522 30131523 3 www.national.com AN-2084 LMZ14203EXT Thermal Derating LMZ12003EXT Thermal Derating 30131515 30131516 LMZ14202EXT Thermal Derating LMZ12002EXT Thermal Derating 30131524 30131525 LMZ14201EXT Thermal Derating LMZ12001EXT Thermal Derating 30131527 30131526 www.national.com 4 LMZ12003EXT Current Limit VOUT = 1.8V 30131528 30131529 LMZ14202EXT Current LimitVOUT = 3.3V LMZ12002EXT Current Limit VOUT = 1.8V 30131530 30131531 LMZ14201EXT Current Limit VOUT = 3.3V LMZ12001EXT Current Limit VOUT = 1.8V 30131533 30131532 5 www.national.com AN-2084 LMZ14203EXT Current Limit VOUT = 3.3V AN-2084 LMZ14203EXT Startup VIN = 12V LMZ12003EXT Startup VIN = 12V 30131535 30131534 LMZ14203EXT Output Ripple VOUT = 3.3V IOUT = 3A, BW = 200 MHz LMZ14203EXT Transient Response VIN = 24V VOUT = 3.3V, 0.6 A to 3A Step 30131518 30131517 PCB Layout Diagrams Gerber and CAD files can be download from the LMZ14203EXT product folder. 30131509 FIGURE 2. Top Layer www.national.com 6 AN-2084 30131510 FIGURE 3. Internal Layer I (Ground) Heat Sinking Layer 30131511 FIGURE 4. Internal Layer II (Ground) Heat Sinking Layer 30131512 FIGURE 5. Bottom Layer (Ground and Routing) Heat Sinking Layer 7 www.national.com AN-2084 30131513 FIGURE 6. LMZ14203EXT PCB CAD package schematic DNS = Component not installed www.national.com 8 AN-2084 Notes 9 www.national.com LMZ1420xEXT / LMZ1200xEXT Evaluation Board Notes For more National Semiconductor product information and proven design tools, visit the following Web sites at: www.national.com Products Design Support Amplifiers www.national.com/amplifiers WEBENCH(R) Tools www.national.com/webench Audio www.national.com/audio App Notes www.national.com/appnotes Clock and Timing www.national.com/timing Reference Designs www.national.com/refdesigns Data Converters www.national.com/adc Samples www.national.com/samples Interface www.national.com/interface Eval Boards www.national.com/evalboards LVDS www.national.com/lvds Packaging www.national.com/packaging Power Management www.national.com/power Green Compliance www.national.com/quality/green Switching Regulators www.national.com/switchers Distributors www.national.com/contacts LDOs www.national.com/ldo Quality and Reliability www.national.com/quality LED Lighting www.national.com/led Feedback/Support www.national.com/feedback Voltage References www.national.com/vref Design Made Easy www.national.com/easy www.national.com/powerwise Applications & Markets www.national.com/solutions Mil/Aero www.national.com/milaero PowerWise(R) Solutions Serial Digital Interface (SDI) www.national.com/sdi Temperature Sensors www.national.com/tempsensors SolarMagicTM www.national.com/solarmagic PLL/VCO www.national.com/wireless www.national.com/training PowerWise(R) Design University THE CONTENTS OF THIS DOCUMENT ARE PROVIDED IN CONNECTION WITH NATIONAL SEMICONDUCTOR CORPORATION ("NATIONAL") PRODUCTS. NATIONAL MAKES NO REPRESENTATIONS OR WARRANTIES WITH RESPECT TO THE ACCURACY OR COMPLETENESS OF THE CONTENTS OF THIS PUBLICATION AND RESERVES THE RIGHT TO MAKE CHANGES TO SPECIFICATIONS AND PRODUCT DESCRIPTIONS AT ANY TIME WITHOUT NOTICE. NO LICENSE, WHETHER EXPRESS, IMPLIED, ARISING BY ESTOPPEL OR OTHERWISE, TO ANY INTELLECTUAL PROPERTY RIGHTS IS GRANTED BY THIS DOCUMENT. TESTING AND OTHER QUALITY CONTROLS ARE USED TO THE EXTENT NATIONAL DEEMS NECESSARY TO SUPPORT NATIONAL'S PRODUCT WARRANTY. EXCEPT WHERE MANDATED BY GOVERNMENT REQUIREMENTS, TESTING OF ALL PARAMETERS OF EACH PRODUCT IS NOT NECESSARILY PERFORMED. NATIONAL ASSUMES NO LIABILITY FOR APPLICATIONS ASSISTANCE OR BUYER PRODUCT DESIGN. BUYERS ARE RESPONSIBLE FOR THEIR PRODUCTS AND APPLICATIONS USING NATIONAL COMPONENTS. PRIOR TO USING OR DISTRIBUTING ANY PRODUCTS THAT INCLUDE NATIONAL COMPONENTS, BUYERS SHOULD PROVIDE ADEQUATE DESIGN, TESTING AND OPERATING SAFEGUARDS. EXCEPT AS PROVIDED IN NATIONAL'S TERMS AND CONDITIONS OF SALE FOR SUCH PRODUCTS, NATIONAL ASSUMES NO LIABILITY WHATSOEVER, AND NATIONAL DISCLAIMS ANY EXPRESS OR IMPLIED WARRANTY RELATING TO THE SALE AND/OR USE OF NATIONAL PRODUCTS INCLUDING LIABILITY OR WARRANTIES RELATING TO FITNESS FOR A PARTICULAR PURPOSE, MERCHANTABILITY, OR INFRINGEMENT OF ANY PATENT, COPYRIGHT OR OTHER INTELLECTUAL PROPERTY RIGHT. LIFE SUPPORT POLICY NATIONAL'S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS PRIOR WRITTEN APPROVAL OF THE CHIEF EXECUTIVE OFFICER AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: Life support devices or systems are devices which (a) are intended for surgical implant into the body, or (b) support or sustain life and whose failure to perform when properly used in accordance with instructions for use provided in the labeling can be reasonably expected to result in a significant injury to the user. A critical component is any component in a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system or to affect its safety or effectiveness. National Semiconductor and the National Semiconductor logo are registered trademarks of National Semiconductor Corporation. All other brand or product names may be trademarks or registered trademarks of their respective holders. AN-2084 Copyright(c) 2010 National Semiconductor Corporation For the most current product information visit us at www.national.com National Semiconductor Americas Technical Support Center Email: support@nsc.com Tel: 1-800-272-9959 www.national.com National Semiconductor Europe Technical Support Center Email: europe.support@nsc.com National Semiconductor Asia Pacific Technical Support Center Email: ap.support@nsc.com National Semiconductor Japan Technical Support Center Email: jpn.feedback@nsc.com IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. All products are sold subject to TI's terms and conditions of sale supplied at the time of order acknowledgment. TI warrants performance of its hardware products to the specifications applicable at the time of sale in accordance with TI's standard warranty. Testing and other quality control techniques are used to the extent TI deems necessary to support this warranty. Except where mandated by government requirements, testing of all parameters of each product is not necessarily performed. TI assumes no liability for applications assistance or customer product design. Customers are responsible for their products and applications using TI components. To minimize the risks associated with customer products and applications, customers should provide adequate design and operating safeguards. TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right, copyright, mask work right, or other TI intellectual property right relating to any combination, machine, or process in which TI products or services are used. Information published by TI regarding third-party products or services does not constitute a license from TI to use such products or services or a warranty or endorsement thereof. Use of such information may require a license from a third party under the patents or other intellectual property of the third party, or a license from TI under the patents or other intellectual property of TI. Reproduction of TI information in TI data books or data sheets is permissible only if reproduction is without alteration and is accompanied by all associated warranties, conditions, limitations, and notices. Reproduction of this information with alteration is an unfair and deceptive business practice. TI is not responsible or liable for such altered documentation. Information of third parties may be subject to additional restrictions. Resale of TI products or services with statements different from or beyond the parameters stated by TI for that product or service voids all express and any implied warranties for the associated TI product or service and is an unfair and deceptive business practice. TI is not responsible or liable for any such statements. TI products are not authorized for use in safety-critical applications (such as life support) where a failure of the TI product would reasonably be expected to cause severe personal injury or death, unless officers of the parties have executed an agreement specifically governing such use. Buyers represent that they have all necessary expertise in the safety and regulatory ramifications of their applications, and acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related requirements concerning their products and any use of TI products in such safety-critical applications, notwithstanding any applications-related information or support that may be provided by TI. Further, Buyers must fully indemnify TI and its representatives against any damages arising out of the use of TI products in such safety-critical applications. TI products are neither designed nor intended for use in military/aerospace applications or environments unless the TI products are specifically designated by TI as military-grade or "enhanced plastic." Only products designated by TI as military-grade meet military specifications. Buyers acknowledge and agree that any such use of TI products which TI has not designated as military-grade is solely at the Buyer's risk, and that they are solely responsible for compliance with all legal and regulatory requirements in connection with such use. TI products are neither designed nor intended for use in automotive applications or environments unless the specific TI products are designated by TI as compliant with ISO/TS 16949 requirements. Buyers acknowledge and agree that, if they use any non-designated products in automotive applications, TI will not be responsible for any failure to meet such requirements. Following are URLs where you can obtain information on other Texas Instruments products and application solutions: Products Applications Audio www.ti.com/audio Communications and Telecom www.ti.com/communications Amplifiers amplifier.ti.com Computers and Peripherals www.ti.com/computers Data Converters dataconverter.ti.com Consumer Electronics www.ti.com/consumer-apps DLP(R) Products www.dlp.com Energy and Lighting www.ti.com/energy DSP dsp.ti.com Industrial www.ti.com/industrial Clocks and Timers www.ti.com/clocks Medical www.ti.com/medical Interface interface.ti.com Security www.ti.com/security Logic logic.ti.com Space, Avionics and Defense www.ti.com/space-avionics-defense Power Mgmt power.ti.com Transportation and Automotive www.ti.com/automotive Microcontrollers microcontroller.ti.com Video and Imaging RFID www.ti-rfid.com OMAP Mobile Processors www.ti.com/omap Wireless Connectivity www.ti.com/wirelessconnectivity TI E2E Community Home Page www.ti.com/video e2e.ti.com Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265 Copyright (c) 2011, Texas Instruments Incorporated