Application Note 1926 ISL8270MEVAL1Z Evaluation Board User Guide The ISL8270M is a 25A step-down DC/DC power supply module with integrated digital PWM controller, synchronous power switches, an inductor and passives. Only bulk input and output capacitors are needed to finish the design. The 25A of continuous output current can be delivered without a need of airflow or a heatsink. The ISL8270M uses ChargeModeTM control architecture, which responds to a transient load within a single switching cycle. The ISL8270MEVAL1Z evaluation board is a 3in x 4.5in 4-layer FR4 board with 2 oz. copper in all layers. This evaluation board comes with a placeholder for pin-strap resistors to adjust output voltage, switching frequency, input undervoltage (UVLO) protection threshold, and device PMBus address. More configuration such as soft-start and fault limits can be easily programmed or changed via PMBus compliant serial bus interface. ZLUSBEVAL3Z (USB to PMBus™ adapter) is provided with this evaluation kit, which connects the evaluation board to a PC to activate the PMBus communication interface. The PMBus command set is accessed by using the PowerNavigator™ evaluation software from a PC running Microsoft Windows. References ISL8270M datasheet Ordering Information PART NUMBER ISL8270MEVAL1Z DESCRIPTION ISL8270M Kit (EVB, ZLUSBEVAL3Z Adapter, USB Cable) Key Features • VIN range of 4.5V to 14V, VOUT adjustable from 0.6V to 5V • Programmable VOUT, margining, UV/OV, IOUT limit, soft-start/stop, sequencing, and external synchronization • Monitor: VIN, VOUT, IOUT, temperature, duty cycle, switching frequency and faults • ChargeModeTM control tunable with PMBus • Mechanical switch for enable and power-good LED indicator Recommended Equipment • DC power supply with minimum 15V/20A sourcing capacity • Electronic load capable of sinking current up to 25A • Digital multimeters (DMMs) • Oscilloscope with higher than 100MHz bandwidth Functional Description The ISL8270MEVAL1Z provides all circuitry required to evaluate the features of the ISL8270M. A majority of the features of the ISL8270M, such as compensation-free ChargeModeTM control, soft-start delay and ramp times, supply sequencing, and voltage margining are available on this evaluation board. For sequencing evaluation, the board can be connected to any Intersil digital module evaluation board that supports the Digital-DC™ (DDC) bus. Figure 1 shows a board image of the ISL8270MEVAL1Z evaluation board. INTERCONNECTS DDC AND SYNC BETWEEN BOARDS PGOOD LED INTERCONNECTS DDC AND SYNC BETWEEN BOARDS ENABLE SWITCH CONNECT TO ZLUSBEVAL3Z DONGLE. FOR MULTIPLE BOARD EVALUATION, CONNECT TO PMBUS DONGLE OUT CONNECTION OF OTHER BOARD TO DAISY CHAIN PMBus CONNECTION PLACEHOLDER FOR SMA CONNECTOR TO MONITOR VOUT RIPPLE FIGURE 1. ISL8270MEVAL1Z EVALUATION BOARD IMAGE August 15, 2014 AN1926.1 1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 1-888-468-3774 | Copyright Intersil Americas LLC 2014. All Rights Reserved Intersil (and design), PowerNavigator, ChargeMode, and Digital-DC are trademarks owned by Intersil Corporation or one of its subsidiaries. All other trademarks mentioned are the property of their respective owners. Application Note 1926 Operation PMBus Operation The ISL8270M utilizes the PMBus protocol. The PMBus functionality can be controlled via ZLUSBEVAL3Z dongle from a PC running the PowerNavigator™ evaluation software in a Windows XP or Windows 7 operating systems. Install the evaluation software from the following Intersil website: www.intersil.com/powernavigator For board operation, connect the included ZLUSBEVAL3Z dongle to the 6-pin male connector labeled as “PMBus DONGLE IN”. 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 switches in “DISABLE” before turning on the power. The evaluation software allows modification of all ISL8270M PMBus parameters. The ISL8270M device on the board has been pre-configured as described in this document, but the user may modify the operating parameters through the evaluation software or by loading a predefined set-up from a configuration file. A sample “Configuration File” on page 5 is provided and can be copied to a notepad editor to make desired changes. The ENABLE switch can then be moved to “ENABLE” and the ISL8270MEVAL1Z board can be tested. Alternately, the PMBus ON_OFF_CONFIG and OPERATION commands may be used from the PowerNavigator™ GUI. Quick Start Guide Pin-Strap Option The ISL8270MEVAL1Z can be configured in pin-strap mode with standard 1% 0603 resistors. PMBus interface is not required to evaluate ISL8270M in pin-strap mode. Output voltage (VOUT), switching frequency (FSW), input under-voltage protection (UVLO) threshold and device PMBus address can be changed by populating recommended resistors at placeholders provided in the evaluation board. By default, the evaluation board is programmed to regulate at VOUT = 1.2V, FSW = 533kHz, UVLO = 4.5V, and PMBus address = 28h. Follow these steps to evaluate ISL8270M in pin-strap mode. 1. Set ENABLE switch to “DISABLE”. 2. Connect Load to VOUT lug connectors (J7 and J8). 3. Connect power supply to VIN connectors (J3 and J4). Make sure power supply is not enabled when making connection. 4. Turn power supply on. 5. Set ENABLE switch to “ENABLE”. 6. Measure 1.2V VOUT at probe points (TP10 and TP11). 7. Observe switching frequency of 533kHz at probe point labeled VSWH (TP1). 8. To change VOUT, disconnect board from the setup and populated 1% standard 0603 resistor at R6 placeholder location on bottom layer. Refer to the “Output Voltage Resistor Settings” table in the ISL8270M datasheet for recommended values. By default, VOUT_MAX is set 110% of VOUT set by pin-strap resistor. Submit Document Feedback 2 9. To change switching frequency, disconnect board from the set up and populated 1% standard 0603 resistor at R2 placeholder location on bottom layer. Refer to the “Switching Frequency Resistor Settings” table in the ISL8270M datasheet for recommended values. 10. To change UVLO, disconnect board from the set up and populated 1% standard 0603 resistor at R7 placeholder location on bottom layer. Refer to the “UVLO Resistor Settings” table in the ISL8270M datasheet for recommended values. PMBus Option ISL8270MEVAL1Z can be evaluated for all features using the provided ZLUSBEVAL3Z dongle and PowerNavigator™ evaluation software. Follow these steps to evaluate ISL8270M with PMBus option. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. Install PowerNavigator™ software. Set ENABLE switch to “DISABLE”. Connect Load to VOUT lug connectors (J7 and J8). Connect power supply to VIN connectors (J3 and J4). Make sure power supply is not enabled when making connection. Turn power supply on. Connect ZLUSBEVAL3Z dongle (USB to PMBus™ adapter) to ISL8270MEVAL1Z board to the 6-pin male connector labeled as “PMBus DONGLE IN”. Connect supplied USB cable from computer to USB to ZLUSBEVAL3Z dongle. Launch PowerNavigator™ software. Set ENABLE switch to “ENABLE”. Monitor and configure the ISL8270MEVAL1Z board using PMBus commands in the evaluation software. PowerNavigator™ tutorial videos are available at Intersil website. www.intersil.com/powernavigator For sequencing via Digital-DC™ Bus (DDC) or to evaluate multiple Intersil digital power products using a single ZLUSBEVAL3Z dongle, ISL8270M can be daisy chained with other digital power evaluation boards. PMBus address can be changed by placing a 1% standard 0603 resistor at the R4 placeholder location on the bottom layer. Refer to the “SMBus Address Resistor Selection” table in the ISL8270M datasheet for recommended values. Thermal Considerations and Current Derating Board layout is very critical in order to make the module operate safely and deliver maximum allowable power. To work in the high temperature environments and carry large currents, the board layout needs to be carefully designed to maximize thermal performance. To achieve this, select enough trace width, copper weight and the proper connectors. This evaluation board is designed for running 25A at room temperature without additional cooling systems needed. However, if the output voltage is increased or the board is operated at elevated temperatures, then the available current is derated. Refer to the derated current curves in the ISL8270M datasheet to determine the maximum output current theevaluation board can supply. JA is measured by inserting thermocouple inside the module to measure peak junction temperature. AN1926.1 August 15, 2014 SW1 GT11MCBE 2 MSTR_SYNC R1 1 D1 39 17 18 19 20 21 23 24 VIN PG R9 1K 1 EN 38 SYCN V25 TP2 37 VDDC TP3 C6 10uF Q1 2N7002 UVLO NC VSEN+ 6 VSEN+ VSEN- 7 VSEN- SGND 15 J9 PGND + + R11 200 C14 470uF 2 34 C13 470uF 1 1 TP5 1 TP4 VR6 NC + C5 22uF VSEN+ VIN NC 1 C4 22uF 2 2 J4 1 11 2 C1 150uF 1 C2 150uF 2 + VR5 35 VDRVIN 1 1 2.2 10 36 2 2 PGND 2 R3 C7 1uF 2 1 VIN 2 PHASE 1 TP8 DNP VR6 1 2 C8 10uF J3 5 4 9 C15 1.0uF 2 VDRVOUT 2 3 1 VR5 TP7 8 1 C3 22uF J7 TP10 PGND VOUT 31 14 1 VOUT 1 100 uF C11 2 1 1 100 uF C10 2 2 100 uF C9 2 1 KPA8CTP TP9 VOUT 100 uF C12 J8 1 PGND KPA8CTP 40 TP11 30 U1 ISL8270MIRZ VSWH 13 12 TP1 FIGURE 2. APPLICATION CIRCUIT VSEN- Application Note 1926 SGND TP6 1 VDDC NC 3 2 SCL SDA SA NC PGND MGN VSET 1 DNP XTEMP- PG 16 2 XTEMP+ 3 VDD 2 2 1 2 3 4 5 6 25 2 2 ENABLE 2 DISABLE 1 VR5 R8 10K 6 4 1 2 R4 1 OPEN R6 OPEN 1 PG 2 V25 1 MSTR_SYNC RSVD1 GND DDC RSVD2 RSVD3 1 10K OPEN R2 SALRT 3 2 DDC NC 1 J6 1 2 3 4 5 6 28 R7 OPEN 27 R5 4.7K JP1 J5 1 VR5 29 1 2 3 4 5 6 SGND SDA SALRT SCL GND Vi2c MSTR_EN 1 1 2 3 4 5 6 2 J15 2 3 J1 1 MSTR_EN SCL SDA SALRT 2 Submit Document Feedback ISL8270MEVAL1Z Board Schematic AN1926.1 August 15, 2014 Application Note 1926 Bill of Materials REFERENCE DESIGNATOR QTY MANUFACTURER MANUFACTURER PART DESCRIPTION C7 1 MURATA GRM188R71E105KA12D CAP, SMD, 0603, 1µF, 25V, 10%, X7R, ROHS C3-C5 3 MURATA GRM32ER71E226KE15L CAP, SMD, 1210, 22µF, 25V, 10%, X7R, ROHS C15 1 PANASONIC ECJ-0EB0J105K CAP, SMD, 0402, 1µF, 6.3V, 10%, X5R, ROHS C8 1 PANASONIC ECJ-1VB1A106M CAP, SMD, 0603, 10µF, 10V, 20%, X5R, ROHS C6 1 TDK C2012X5R1E106K CAP, SMD, 0805, 10µF, 25V, 10%, X5R, ROHS C9, C10, C11, C12 4 TDK C3225X5R0J107M CAP, SMD, 1210, 100µF, 6.3V, 20%, X5R, ROHS C1, C2 2 SANYO/PANASONIC 16TQC150MYF CAP-POSCAP, SMD, 7.3X4.3, 150µF, 16V, 20%, 50mΩ, ROHS C13, C14 2 SANYO/PANASONIC 6TPF470MAH CAP TANT 470µF 6.3V 20% TP8, TP10 2 KEYSTONE 5000 CONN-MINI TEST PT, VERTICAL, RED, ROHS TP9, TP11 2 KEYSTONE 5001 CONN-MINI TEST PT, VERTICAL, BLK, ROHS J3, J4 2 KEYSTONE 575-4 CONN-JACK, MINI BANANA, 0.175 PLUG, NICKEL/BRASS, ROHS J2, J6 2 SAMTEC SSQ-103-02-T-D-RA CONN-SOCKET STRIP, TH, 2X3, 2.54mm, TIN, R/A, ROHS J1, J5 2 SAMTEC TSW-103-08-T-D-RA CONN-HEADER, 2X3, BRKAWY, 2.54mm, TIN, R/A, ROHS D1 1 CHICAGO MINIATURE CMD17-21VGC/TR8 LED, SMD, 0805, GREEN, CLEAR, 10mcd, 2.1V, 20mA, 570nm, ROHS U1 1 INTERSIL ISL8270MIRZ IC-25A DIGITAL DC/DC PMBUS MODULE, 26P, QFN, ROHS Q1 1 ON SEMICONDUCTOR 2N7002LT1G TRANSISTOR-MOS, N-CHANNEL, SMD, SOT23, 60V, 115mA, ROHS R5 1 YAGEO RES, SMD, 0603, 4.7k, 1/10W, 1%, TF, ROHS R2, R4, R6, R7 0 R3 1 PANASONIC ERJ-3RQF2R2V RES, SMD, 0603, 2.2Ω, 1/10W, 1%, TF, ROHS R9 1 PANASONIC ERJ-3EKF1001V RES, SMD, 0603, 1k, 1/10W, 1%, TF, ROHS R1, R8 2 KOA RK73H1JT1002F RES, SMD, 0603, 10k, 1/10W, 1%, TF,ROHS R11 1 PANASONIC ERJ-8ENF2000V RES, SMD, 1206, 200Ω, 1/4W, 1%, TF, ROHS SW1 1 ITT CANNON GT11MCBE SWITCH-TOGGLE, THRU-HOLE, SPDT, 5P, ROHS J7, J8 2 BERG/FCI KPA8CTP HDWARE, MTG, CABLE TERMINAL, 6-14AWG, LUG and SCREW, ROHS J9 0 TE CONNECTIVITY 5-1814832-1 DO NOT POPULATE JP1 0 DO NOT POPULATE TP1-TP7 0 DO NOT POPULATE Submit Document Feedback 9C06031A4701FKHFT RESISTOR, SMD, 0603, 0.1%, MF, DNP-PLACE HOLDER 4 AN1926.1 August 15, 2014 Application Note 1926 Configuration File Sample Configuration File for ISL8270M Module. Copy and paste (from RESTORE_FACTORY TO ### End User Store) to a notepad and save it as Confile_file_name.txt. The # symbol is used for a comment line. Following settings are already loaded to ISL8270M module as factory defaults. RESTORE_FACTORY STORE_USER_ALL # VOUT Related VOUT_COMMAND VOUT_MAX VOUT_MARGIN_HIGH VOUT_MARGIN_LOW VOUT_OV_FAULT_LIMIT VOUT_OV_FAULT_RESPONSE VOUT_OV_WARN_LIMIT VOUT_UV_WARN_LIMIT VOUT_UV_FAULT_LIMIT VOUT_UV_FAULT_RESPONSE POWER_GOOD_ON VOUT_TRANSITION_RATE VOUT_DROOP VOUT_CAL_OFFSET # IOUT Related IOUT_CAL_GAIN IOUT_CAL_OFFSET IOUT_OC_FAULT_LIMIT IOUT_UC_FAULT_LIMIT MFR_IOUT_OC_FAULT_RESPONSE MFR_IOUT_UC_FAULT_RESPONSE ISENSE_CONFIG # Other Faults OT_FAULT_LIMIT OT_FAULT_RESPONSE OT_WARN_LIMIT UT_WARN_LIMIT UT_FAULT_LIMIT UT_FAULT_RESPONSE VIN_OV_FAULT_LIMIT VIN_OV_FAULT_RESPONSE VIN_OV_WARN_LIMIT VIN_UV_WARN_LIMIT VIN_UV_FAULT_LIMIT VIN_UV_FAULT_RESPONSE #Enable, Timing and Sequence Related ON_OFF_CONFIG TON_DELAY TON_RISE TOFF_DELAY TOFF_FALL POWER_GOOD_DELAY FREQUENCY_SWITCH SYNC_CONFIG SEQUENCE # Manufacturer Related MFR_ID MFR_MODEL MFR_REVISION MFR_LOCATION MFR_DATE MFR_SERIAL USER_DATA_00 # Advance Settings USER_CONFIG DDC_CONFIG DDC_GROUP # Loop Compensation ASCR_CONFIG STORE_USER_ALL ### End User Store Submit Document Feedback 5 # reset device to the factory setting # Clears user memory space 0x2666 0x2a3c 0x2851 0x247a 0x2c28 0x80 0x2a3c 0x228f 0x20a3 0x80 0x228f 0xba00 0x0000 0x0000 # 1.2 V # 1.32 V # 1.26 V # 1.14 V # 1.38 V # Disable and no retry # 1.32 V # 1.08 V # 1.02 V # Disable and no retry # 1.08 V # 1 mV/us # 0 mV/A # 0 mV/A 0xb380 0x0000 0xdbc0 0xdc3f 0x80 0x80 0x05 # 0.875 mV/A #0A # 30 A # -30A # Disable and no retry # Disable and no retry # 256ns Blanking time, Mid-Range 0xebe8 0x80 0xeb70 0xdc40 0xe530 0x80 0xd380 0x80 0xd327 0xca79 0xca40 0x80 # 125 °C # Disable and no retry # 110 °C # -30 °C # -45 °C # Disable and no retry # 14 V # Disable and no retry # 12.609 V # 4.945 V # 4.5 V # Disable and no retry 0x17 0xca80 0xca80 0xca80 0xca80 0xba00 0x0215 0x00 0x0000 # Pin Enable, Immediate Off # 5 ms # 5 ms # 5 ms # 5 ms # 1 ms # Sequence Disabled # Use Pin-strap for FSW setting # 533 kHz Intersil Corp ISL8270MEVAL1Z Rev-1 Milpitas, CA 3/14/2014 1234 Module # Example Only # Example Only # Example Only # Example Only # Example Only # Example Only # Example Only 0x00 0x01 0x00000000 # Open Drain PG, XTEMP Disabled # DDC rail ID = 1 # All Broadcast disabled 0x15a0100 # Store all above settings to NVRAM # ASCR gain = 256, Residual = 90 AN1926.1 August 15, 2014 Application Note 1926 Measured Data The following data was acquired using a ISL8270MEVAL1Z evaluation board. 100 96 95 94 92 EFFICIENCY (%) EFFICIENCY (%) 90 85 80 1.8V 2.5V 1V 75 1.2V 0.8V 3.3V 70 65 60 3.3V 90 88 1.8V 86 84 82 1V 80 5V (727kHz) 3 5 7 9 11 13 15 17 19 21 23 25 1.2V 0.8V 78 1 5V 2.5V 300 400 IOUT (A) 500 600 FIGURE 3. EFFICIENCY vs OUTPUT CURRENT AT VIN = 12V, FSW = 550kHz FOR VARIOUS OUTPUT VOLTAGES 96 95 94 90 92 1.8V 2.5V EFFICIENCY (%) EFFICIENCY (%) 80 3.3V 1V 75 0.8V 70 900 2.5V 3.3V 1.2V 800 FIGURE 4. EFFICIENCY vs SWITCHING FREQUENCY AT VIN = 12V, IOUT = 25A FOR VARIOUS OUTPUT VOLTAGES 100 85 700 SWITCHING FREQUENCY (kHz) 90 1.2V 88 1.8V 86 84 82 65 1V 0.8V 60 80 1 3 5 7 9 11 13 15 IOUT (A) 17 19 21 23 25 FIGURE 5. EFFICIENCY vs OUTPUT CURRENT AT VIN = 5V, FSW = 550kHz FOR VARIOUS OUTPUT VOLTAGES 300 400 500 600 700 800 SWITCHING FREQUENCY (kHz) 900 FIGURE 6. EFFICIENCY vs SWITCHING FREQUENCY AT VIN = 5V, IOUT = 25A FOR VARIOUS OUTPUT VOLTAGES VOUT (50mV/DIV) FSW = 550kHz PL AC EH O E LD R ASCR GAIN = 650 RESIDUAL = 60 IOUT (5A/DIV) 20µs/DIV FIGURE 7. 1.2V TRANSIENT RESPONSE Submit Document Feedback 6 2: 53.3°C 1: 59.7°C TA = +25°C FIGURE 8. THERMAL IMAGE, 12VIN to 1VOUT, IOUT = 25A, TA = +25°C, FSW = 533kHz, NO AIR FLOW AN1926.1 August 15, 2014 Application Note 1926 ISL8270MEVAL1Z Board Layout FIGURE 9. PCB - TOP SILK SCREEN FIGURE 10. PCB - TOP LAYER Submit Document Feedback 7 AN1926.1 August 15, 2014 Application Note 1926 ISL8270MEVAL1Z Board Layout (Continued) FIGURE 11. PCB - INNER LAYER - LAYER 2 (TOP VIEW) FIGURE 12. PCB - INNER LAYER - LAYER 3 (TOP VIEW) Submit Document Feedback 8 AN1926.1 August 15, 2014 Application Note 1926 ISL8270MEVAL1Z Board Layout (Continued) FIGURE 13. PCB - BOTTOM LAYER (BOTTOM VIEW) 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 Submit Document Feedback 9 AN1926.1 August 15, 2014