Application Note 1517 ZL2008EVAL1Z Evaluation Board Description Features The ZL2008 is an integrated mixed-signal power conversion and management IC that combines an efficient step-down DC/DC converter with key power and thermal management functions in a single package. The ZL2008 incorporates current sharing and adaptive efficiency-optimization algorithms to provide a flexible, efficient power IC building block. * 15A synchronous buck converter The ZL2008EVAL1Z platform is a 4-layer board demonstrating a 15A synchronous buck converter. Sequencing, tracking, margining, plus other features can be evaluated using this board. * Power good indicator A USB to SMBus adapter board can be used to connect the eval board to a PC. The PMBus command set is accessed by using the Zilker Labs PowerNavigatorTM evaluation software from a PC running Microsoft Windows. * VOUT = 1.2V/15A (20A max) * Optimized for small circuit footprint and dynamic response * Configurable through SMBus * Onboard enable switch Target Specifications * VIN = 12V * fsw = 615kHz * Efficiency: 86% at 10A * Output ripple: 1% * Dynamic response: 3% (50%-100%-50% load step, di/dt = 2.5A/s) * Board temperature: +25C VIN EN S Y NC ZL2008 VOUT DDC S MB us ENABLE PINSTRAP VTRK SW 1 J10 J11 S Y NC DDC S MB us TRA CK PG S Y NC DDC S MB us TRA CK PG FIGURE 1. ZL2008EVAL1Z BLOCK DIAGRAM March 15, 2010 AN1517.1 1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright Intersil Americas Inc. 2009, 2010. All Rights Reserved All other trademarks mentioned are the property of their respective owners. Application Note 1517 Functional Description The ZL2008EVAL1Z provides all circuitry required to demonstrate the features of the ZL2008. The ZL2008EVAL1Z has a functionally-optimized ZL2008 circuit layout that allows efficient operation up to the maximum output current. Power and load connections are provided through plug-in sockets. A majority of the features of the ZL2008 such as softstart delay and ramp times, supply sequencing, voltage tracking, and voltage margining are available on this evaluation board. For voltage tracking and sequencing evaluation, the board can be connected to any other Zilker Labs evaluation board that supports the Digital DC (DDC) bus. the eval software or by loading a predefined scenario from a configuration file. Use the mouse-over pop-ups for PowerNavigator help. Refer to Zilker Labs application note AN2033 for PMBus details. The ENABLE switch can then be moved to "ENABLE" and the ZL2008EVAL1Z board can be tested. Alternately, the PMBus ON-OFF CONFIG and OPERATION commands may be used. Quick Start Guide Stand Alone Operation 1. Set ENABLE switch to "DISABLE" Figure 1 shows a functional block diagram of the ZL2008EVAL1Z board. The SMBus address is selectable through a jumper on the top side of the board. All power to the board (VIN and I2C bus) must be removed before changing the jumpers. 2. Apply load to VOUT+/VOUT- The hardware enable function is controlled by a toggle switch on the ZL2008EVAL1Z board. The power good (PG) LEDs indicate the correct state of PG when external power is applied to the ZL2008EVAL1Z board. The right angle headers at opposite ends of the board are for connecting a USB to SMBus adapter board or for daisy chaining of multiple evaluation boards. 5. Connect power supply to VIN+/VIN- (supply turned off) Figure 2 shows the operational circuit. The circuit consists of the ZL2008 IC with its minimal component count to realize a 15A buck converter. The board layout has been optimized for thermal performance. Figure 3 is the board interface circuitry. Figure 4 through Figure 8 show the PCB layout for the board including the board fabrication notes. The bill of materials (BOM) and configuration file are also included for reference. Operation 3. Connect the USB to SMBus adapter board to J10 of ZL2008EVAL1Z 4. Connect supplied USB cable from computer to USB to SMBus adapter board 6. Turn power supply on 7. Set ENABLE switch to "ENABLE" 8. Monitor ZL2008EVAL1Z board operation using an oscilloscope USB (PMBus) Operation 1. Set ENABLE switch to "DISABLE" 2. Apply load to VOUT+/VOUT3. Connect power supply to VIN+/VIN- (supply turned off) 4. Turn power supply on 5. Insert the Zilker Labs Eval Kit CD 6. Connect USB to SMBus adapter board to J10 of ZL2008EVAL1Z 7. Connect supplied USB cable from computer to USB to SMBus adapter board PMBus Operation The ZL2008 utilizes the PMBus protocol. The PMBus functionality can be controlled via USB from a PC running the PowerNavigator evaluation software in a Windows XP or Windows 2000/NT operating system. Install the evaluation software using the CD included in the ZL2008EVAL1Z kit. For board operation, connect the included USB-to-SMBus adapter board to J10 of the ZL2008EVAL1Z board. Connect the desired load and an appropriate power supply to the input and connect the included USB cable to the PC running the PowerNavigator evaluation software. Place the ENABLE switch in "DISABLE" and turn on the power. The evaluation software allows modification of all ZL2008 PMBus parameters. The ZL2008 device on the board has been pre-configured as described in this document, but the user may modify the operating parameters through 2 - Upon first-time connection, the Found New Hardware Wizard will appear. - Windows XP users: Select `No' at prompt to search the Internet for drivers. - Follow the steps on the screen to install the drivers from the CD. 8. Install the PowerNavigator evaluation software by running setup.exe from the PowerNavigator_installer folder on the CD. 9. Set ENABLE switch on EVB to "ENABLE" 10.Monitor and configure the ZL2008EVAL1Z board using PMBus commands in the evaluation software 11.Test the ZL2008EVAL1Z operation using an oscilloscope and the evaluation software. AN1517.1 March 15, 2010 Board Schematics 3 Application Note 1517 AN1517.1 March 15, 2010 FIGURE 2. ZL2008EVAL1Z OPERATIONAL CIRCUIT Board Schematics (Continued) 4 Application Note 1517 AN1517.1 March 15, 2010 FIGURE 3. ZL2008EVAL1Z INTERFACE CIRCUITRY Application Note 1517 Board Layout - 4 Layers FIGURE 4. PCB - TOP LAYER 5 AN1517.1 March 15, 2010 Application Note 1517 Board Layout - 4 Layers (Continued) FIGURE 5. PCB - INNER LAYER 1 (VIEWED FROM TOP) 6 AN1517.1 March 15, 2010 Application Note 1517 Board Layout - 4 Layers (Continued) FIGURE 6. PCB - INNER LAYER 2 (VIEWED FROM TOP) 7 AN1517.1 March 15, 2010 Application Note 1517 Board Layout - 4 Layers (Continued) FIGURE 7. PCB - BOTTOM LAYER (VIEWED FROM TOP) 8 AN1517.1 March 15, 2010 Application Note 1517 FIGURE 8. BOARD FABRICATION NOTES 9 AN1517.1 March 15, 2010 Bill of Materials 10 Application Note 1517 AN1517.1 March 15, 2010 Application Note 1517 Configuration Text The following configuration text is loaded into the ZL2008 device on the ZL2008EVAL1Z. The configuration is stored in the DEFAULT store. Each PMBus command can be viewed via the PowerNavigator software. The text following the # symbol is used for a comment. #ZL2008 #PowerPlan file #11/30/2009 #NOTE: This file is intended for the ZL2008EVAL1Z #with L=400nH, Co=5x(100uF/2.0mohm)+(2X680uF/10mohm) #Configuration File Format: #PMBus Command <tab> Hex Value #Erase user store & default store RESTORE_FACTORY STORE_USER_ALL STORE_DEFAULT_ALL MFR_ID MFR_MODEL MFR_REVISION MFR_LOCATION #MFR_DATE Zilker_Labs ZL2008EVAL1Z Rev7 Austin_TX VOUT_COMMAND 1.20#V IOUT_SCALE IOUT_CAL_OFFSET 0.7 2 #mOhm #A IOUT_OC_FAULT_LIMIT IOUT_AVG_OC_FAULT_LIMIT IOUT_UC_FAULT_LIMIT IOUT_AVG_UC_FAULT_LIMIT MFR_IOUT_OC_FAULT_RESPONSE MFR_IOUT_UC_FAULT_RESPONSE 45.0 38.0 -15.0 -12.0 0x80 0x80 #A #A #A #A VIN_OV_FAULT_LIMIT VIN_OV_WARN_LIMIT VIN_OV_FAULT_RESPONSE VIN_UV_WARN_LIMIT VIN_UV_FAULT_LIMIT VIN_UV_FAULT_RESPONSE 14.0 13.5 0x80 4.641 4.50 0x80 #V #V #V #V POWER_GOOD_DELAY TON_DELAY TON_RISE TOFF_DELAY TOFF_FALL 1 5 5 5 5 DEADTIME DEADTIME_CONFIG 0x2424 0x0404 MAX_DUTY INDUCTOR 95 0.4 #uH FREQUENCY_SWITCH 400 #kHz PID_TAPS A=13682.50, B=-23641.00, C=9993.75 11 #ms #ms #ms #ms #ms AN1517.1 March 15, 2010 Application Note 1517 Configuration Text (Continued) # Advanced USER_CONFIG MFR_CONFIG #NLR_CONFIG TEMPCO_CONFIG 0x6010 0x6AD5 0xE1060C00 0xA8 # Advanced 2 MISC_CONFIG DDC_CONFIG DDC_GROUP 0x0080 0x0101 0x00000000 STORE_DEFAULT_ALL RESTORE_DEFAULT_ALL 12 AN1517.1 March 15, 2010 Application Note 1517 Measured Data The following data was acquired using a ZL2008EVAL1Z rev 2 evaluation board. Efficiency Adaptive diode emulation and adaptive frequency modes are disabled for these efficiency measurements. 90 EFFICIENCY (%) 88 86 84 82 80 78 76 74 0 2 4 6 8 10 OUTPUT CURRENT (A) 12 14 16 FIGURE 9. EFFICIENCY, VIN = 12V, VOUT = 1.2V Ramp-up/Ramp-down Characteristics 1.4 OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0 -0.2 0 1.2 1.0 0.8 0.6 0.4 0.2 0 -0.2 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.10 TIME (s) 0 FIGURE 10. RAMP UP 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.10 TIME (s) FIGURE 11. RAMP DOWN Dynamic Load Response 0.005 0.030 0.025 0 VOUT (V) 0.020 VOUT (V) -0.005 -0.010 0.015 0.010 0.005 0 -0.015 -0.005 -0.020 0 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18 0.20 TIME (s) FIGURE 12. DYNAMIC RESPONSE, 7A TO 15A LOAD STEP 13 -0.010 0 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18 0.20 TIME (s) FIGURE 13. DYNAMIC RESPONSE, 15A TO 7A LOAD STEP AN1517.1 March 15, 2010 Application Note 1517 References ZL2008 Data Sheet, Zilker Labs, Inc., 2008. AN2033 - PMBusTM Command Set, Zilker Labs, Inc., 2008. Ordering Information ORDERABLE PART NUMBER ZL2008EVAL1Z DESCRIPTION ZL2008 Evaluation Kit (EVB, USB Adapter, Cable, Software) Revision History DATE REV. # DESCRIPTION March 2010 AN1517.1 In "Target Specifications" on page 1, changed "Dynamic response: 2.5%" to "Dynamic response: 3%" December 2009 AN1517.0 Initial release Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the reader is cautioned to verify that the Application Note or Technical Brief is current before proceeding. For information regarding Intersil Corporation and its products, see www.intersil.com 14 AN1517.1 March 15, 2010 Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: Intersil: ZL2008EVAL1Z