User Guide 072 ISL8205MEVAL1Z Evaluation Board User Guide The ISL8205M power module is a single channel synchronous step-down complete power supply, capable of delivering up to 5A of continuous current. Operating from a single 2.6V to 5.5V input power rail and integrating a controller, power inductor and MOSFETs, ISL8205M can achieve up to 95% conversion efficiency. It also provides fast transient response with excellent loop stability as well as deliver output voltage as low as 0.6V. Switching frequency is also adjustable from 680kHz to 3.5MHz with either external resistor or SYNC clock option. Selectable PFM mode can also be enabled to boost up light load efficiency to extend battery life. Other features include programmable soft-start, soft-stop, input undervoltage lockout, 100% duty cycle operation, over-temperature, overcurrent/short-circuit with hiccup mode, overvoltage and negative overcurrent protection. It also has a dedicated enable pin and power-good flag that allow for easy system power rails sequencing. The ISL8205MEVAL1Z evaluation board is designed to demonstrate the performance of the ISL8205M. The board is by default set to be 1.2V output voltage with 1.6MHz switching frequency. Other output voltage values can be easily set by changing the jumper position. Switching frequency can be adjusted by changing the FS pin resistor. Features • 2.6V to 5.5V input voltage range • Adjustable output voltage as low as 0.6V with ±1.6% accuracy over line/load/temperature • Default 1.8MHz current mode control operations - 680kHz to 3.5MHz resistor adjustable - External synchronization up to 3.5MHz - Selectable light-load efficiency mode - 100% duty cycle LDO mode • Programmable soft-start and soft-stop output discharge • Dedicated enable pin and power-good flag • UVLO, over-temperature, overcurrent, overvoltage and negative overcurrent protections Specifications/Default Set-Up • VIN = 2.6V to 5.5V • VOUT options (via jumper selection): 1V, 1.2V, 2.5V, 3.3V • MAX IOUT up to 5A • fSW = 1.6MHz by default References • Set to PWM mode by default • ISL8205M datasheet • 1ms soft-start time by default Ordering Information PART NUMBER ISL8205MEVAL1Z DESCRIPTION ISL8205M single 5A power module evaluation board FIGURE 1. ISL8205MEVAL1Z BLOCK DIAGRAM May 3, 2016 UG072.0 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 2016. All Rights Reserved Intersil (and design) is a trademark owned by Intersil Corporation or one of its subsidiaries. All other trademarks mentioned are the property of their respective owners. User Guide 072 TABLE 1. ISL8205M COMPONENT SELECTION GUIDE MATRIX VIN (V) VOUT (V) fSW (MHz) CIN (µF) COUT (µF) R7 (kΩ) RSET (kΩ) CFF (pF) 5 0.6 0.8 2x22 1x100 261 OPEN 390 5 0.9 1.2 2x22 3x22 169 200 560 5 1 1.3 2x22 3x22 154 150 560 5 1 1.3 2x22 2x22 154 150 820 5 1.2 1.6 2x22 2x22 124 100 820 5 1.5 1.7 2x22 2x22 115 66.5 560 5 1.8 2 2x22 2x22 95.3 49.9 470 5 2.5 2.5 2x22 2x22 75 31.6 330 5 3.3 3 2x22 2x22 59 22.1 330 3.3 0.6 0.8 2x22 1x100 261 OPEN 390 3.3 0.9 1.2 2x22 3x22 169 200 560 3.3 1 1.3 2x22 3x22 154 150 560 3.3 1 1.3 2x22 2x22 154 150 820 3.3 1.2 1.6 2x22 2x22 124 100 820 3.3 1.5 1.7 2x22 2x22 115 66.5 560 3.3 1.8 2 2x22 2x22 95.3 49.9 470 3.3 2.5 2.5 2x22 2x22 75 31.6 330 FIGURE 2. TOP OF BOARD Recommended Equipment • 0V to 5.5V power supply with at least 7A source current capability • Electronic load capable of sinking current up to 5A • Digital Multimeters (DMMs) • 100MHz quad-trace oscilloscope Functional Description The ISL8205M is a single 5A step-down high efficiency power module optimized for FPGA, DSP and Li-ion battery power devices. The module switches at 1.8MHz by default when the FS pin is shorted to VIN. The switching frequency is also adjustable from 680kHz to 3.5MHz through a resistor from FS to SGND. To Submit Document Feedback 2 FIGURE 3. BOTTOM OF BOARD boost light-load efficiency, ISL8205M can also be configured to operate in PFM mode by pulling the SYNC pin to SGND. Peak current mode control scheme is implemented for fast transient response. The module utilizes internal compensation to stabilize the system and optimize transient response, which greatly simplifies the application. Other excellent features include external synchronization, 100% duty cycle operation and very low quiescent current. For further information, please refer to the ISL8205M datasheet. Quick Start The ISL8205MEVAL1Z is set to be VOUT = 1.2V, fSW = 1.6MHz by default. For other VOUT options, the recommended fSW needs to be adjusted by changing resistor (R7) connected to the FS pin. UG072.0 May 3, 2016 User Guide 072 1. Before applying power to input, ensure one shorting jumper on J1 across pins 5 and 6 is present. This selects VOUT = 1.2V option. 2. Set the ENABLE switches SW1 to the “OFF” position. 3. Connect the positive of a power supply to the VIN connector and the negative of the power supply to the PGND connector. Make sure the power supply is not enabled when making connections and the input power supply voltage is set to a value between 2.6V and 5.5V. 4. Turn the power supply on. 5. Turn ENABLE switch SW1 to the “ON” position to enable module operation. 6. The power-good LED should illuminate in green if the module is operating properly. 7. Measure output voltage, VOUT, at test points VOUT and PGND. Module output should be 1.2V. Programming the Output Voltage The ISL8205MEVAL1Z evaluation board has several preset output voltages, 1.0V, 1.2V, 2.5V and 3.3V, which can be selected in J1 jumper. Other VOUT values other than on-board options can be set by proper selection of the resistor (RSET) connecting from FB to SGND. In this case, RSET for default options (R9, R10, R11, R12) may need to be changed. The output voltage is governed by Equation 1. R SET + 100k V OUT = V REF ---------------------------------------R (EQ. 1) information on recommended switching frequency and fSW selection range is provided in “Recommended Switching Frequency” and “Operation Range”. Recommended Switching Frequency Selection of switching frequency for each VIN and VOUT combination needs to take into account a few trade-offs. Generally, lower switching frequency will lead to higher efficiency. However, switching frequency should not be decreased too low due to negative current protection limit. Moreover, when output voltage is relatively high, low switching frequency will result in more sub-harmonic oscillation. Therefore, operating frequency needs to be kept relatively high under high VOUT conditions. However, again, switching frequency cannot be increased too much. Otherwise, the minimum on-time limit could be violated. Based on these considerations, Figure 4 provides the recommended switching frequency under various typical VIN and across VOUT ranges. 4.0 SWITCHING FREQUENCY (MHz) Please refer to Table 1 for more information. The following operation procedure will be based on default setting. VIN=5V VIN=4V Series3 VIN=2.6V 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 SET 0.6 For most popular VOUT values and corresponding RSET values, please refer to Table 1 for more information. 1 1.4 1.8 2.2 2.6 3 3.4 3.8 OUTPUT VOLTAGE (V) 4.2 4.6 5 FIGURE 4. SWITCHING FREQUENCY RECOMMENDATION Operation Range Feed-Forward Capacitor Selection In typical applications where the output capacitors are all ceramic, a feed-forward capacitor, CFF (as annotated as C12, C13, C14, C15 in schematic) is needed to be put in parallel with each RSET to insure loop stability in extreme operating conditions. With internal compensation mode enabled, the CFF values for typical operating conditions are optimized and listed in Table 1. And that’s how C12, C13, C14, C15 default values are selected. Please note that, for system parameters that are different from Table 1 or external instead of internal compensation is used, the optimized value of CFF needs to be adjusted. By default, the ISL8205MEVAL1Z is configured to be operating at VOUT = 1.2V (J1 jumper position is at pins 5 and 6), fSW = 1.6MHz conditions. VIN ranges from 2.6V to 5.5V. The board can also support a wider operating range to meet the requirement of specific applications. The VOUT can be adjusted from 0.6V to 5V. Load current range is from 0A to 5A. Note that, for continuous operation at 5A, airflow across the board may be needed. The fSW can also be tuned. However, to ensure sufficient stability margins, switching frequency can only be adjusted within the safe operatiing regions represented with Figures 5 through 9. Operating outside of these areas may lead to system instability. Frequency Adjust The switching frequency of ISL8205M is adjustable ranging from 680kHz to 3.5MHz via a simple resistor RFS (as shown in R7 on ISL8205MEVAL1Z board) across FS to SGND. The switching frequency setting is based on Equation 2: 220 10 3 R FS k = ------------------------------ – 14 f OSC kHz (EQ. 2) When the FS pin is directly tied to VIN, the frequency of operation is fixed at 1.8MHz. For a recommended switching frequency with typical operation conditions, refer to Table 1. More detailed Submit Document Feedback 3 UG072.0 May 3, 2016 4.0 SWITCHING FREQUENCY (MHz) SWITCHING FREQUENCY (MHz) User Guide 072 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 0.6 1 1.4 1.8 2.2 2.6 3 3.4 3.8 4.2 4.6 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 5 0.6 1 1.4 1.8 OUTPUT VOLTAGE (V) 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.6 0.9 1.2 1.5 1.8 2.1 2.4 2.6 3 3.4 3.8 4.2 FIGURE 6. OPERATION REGION VIN = 5.0V SWITCHING FREQUENCY (MHz) SWITCHING FREQUENCY (MHz) FIGURE 5. OPERATION REGION VIN = 5.5V 0.0 2.2 OUTPUT VOLTAGE (V) 2.7 3 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 3.3 0.6 0.8 1 OUTPUT VOLTAGE (V) 1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8 OUTPUT VOLTAGE (V) FIGURE 8. OPERATION REGION VIN = 3.3V FIGURE 7. OPERATION REGION VIN = 4.0V SWITCHING FREQUENCY (MHz) 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 0.6 0.8 1 1.2 1.4 1.6 1.8 2 OUTPUT VOLTAGE (V) FIGURE 9. OPERATION REGION VIN = 2.6V Submit Document Feedback 4 UG072.0 May 3, 2016 User Guide 072 PWM/PFM Selection By default, ISL8205MEVAL1Z is set to operate in PWM mode. This is achieved by connecting SYNC to VIN through R1. Pulling the SYNC pin LOW, forces the module into PFM mode, which enables pulse-skipping at light load to minimize the switching loss by reducing the switching frequency. Refer to ISL8205M datasheet for more detailed information. For ISL8205MEVAL1Z, PFM mode can be enabled by removing R1 and shorting SYNC to SGND by putting a 0Ω resistor on R2. Soft Start-Up The soft start-up reduces the inrush current during the start-up. For ISL8205MEVAL1Z, the soft start-up time is set to 1ms by default through C6. However, start-up time can be adjusted by tuning the C6 value. Equation 3 can be used to determine the C6 value for the target soft-start time tSS. C 6 F = 3.1 t SS S (EQ. 3) Thermal Considerations and Current Derating Board layout is very critical in order to make the module operate safely and deliver maximum allowable power. In order for the board to operate properly in the high ambient temperature environments and carry full load currents, the board layout needs to be carefully designed to maximize thermal performance. To achieve this, select enough trace width, copper weight and proper connectors. The ISL8205MEVAL1Z evaluation board is capable of operating at 5A full load current at room temperature with plenty of safety margin for junction temperature. However, if the board is to operate at elevated ambient temperatures, then the available output current may need to be derated. Refer to the derated current curves in the ISL8205M datasheet to determine the maximum output current the evaluation board can supply. Evaluation Board Information The ISL8205MEVAL1Z evaluation board is a 2x2in2 four-layer FR-4 board with 2oz. copper on all the layers. The board can be used as a single 5A reference design. Refer to Figures 11 through 14 for board layout information. The board is designed with mechanical switches for ENABLE, power-good LED indicators, several connectors, test points and jumpers, which make testing the board easy. Submit Document Feedback 5 UG072.0 May 3, 2016 VOUT 7 8 ISL8205MIRZ TP5 NC NC SW SW 9 TP8 6 VOUT BAN3 C9 C8 C7 C11 4 DNP VSENSE DNP 5 22UF NC 0 21 22UF U1 R15 Submit Document Feedback ISL8205MEVAL1Z Schematic PGND VIN TP1 10 OUT NC PGND 6 VIN 11 BAN1 R1 OUT 200K C16 4.7UF C3 22UF C2 22UF C1 DNP C10 DNP PGOOD 12 PG 13 SYNC PGND BAN4 22 SW TP6 PGND 3 PGND E PGND VSENSE UNNAMED_1_ISL8205M_I66_2 2 E BAN2 20 TP3 1 FB COMP FS 16 SS EN PGND 15 R2 TP2 DNP SYNC UNNAMED_1_ISL8205M_I66_16 UNNAMED_1_ISL8205M_I66_17 19 18 17 14 PGND UNNAMED_1_ISL8205M_I66_18 R16 8 6 4 2 4 6 8 7 5 3 1 LED1 TP7 UNNAMED_1_NCHANNEL_I17_D Q1 PGOOD IN 2N7002-7-F DRAWN BY: FIGURE 10. SCHEMATIC DATE: ENGINEER: R12 150K C15 820PF 100K R11 C14 820PF 31.6K R10 C13 390PF R9 22.1K C4 OPEN UNNAMED_1_SMCAP_I111_A DNP R4 330PF C5 124K R7 2K R14 R13 100K SW1 ENABLE UNNAMED_1_CONN8_I67_IN1 UNNAMED_1_CONN8_I67_IN3 UNNAMED_1_CONN8_I67_IN5 UNNAMED_1_CONN8_I67_IN7 0 TP4 UNNAMED_1_SMLED_I105_A VIN OPEN 200K R6 EN IN IN DNP UNNAMED_1_GTSERIES_I4_NC C6 R3 VIN 3300PF R5 C12 E 1 3 5 7 J1 2 UNNAMED_1_CONN8_I67_IN2 DNP User Guide 072 E UG072.0 May 3, 2016 User Guide 072 Bill of Materials REFERENCE DESIGNATOR QTY C16 1 MURATA GRM21BR71A475KA73L C12 1 TDK CGA2B2C0G1H331J050BA CAP, SMD, 0402, 330pF, 50V, 5%, NP0, ROHS C6 1 PANASONIC ECU-E1E332KBQ CAP, SMD, 0402, 3300pF, 25V, 10%, X7R, ROHS C13 1 YAGEO CC0402JRNPO9BN391 CAP, SMD, 0402, 390pF, 50V, 5%, NP0, ROHS C14, C15 2 SAMSUNG CL05C821JB5NNNC CAP, SMD, 0402, 820pF, 50V, 5%, NP0, ROHS C4, C5 0 C2, C3, C7, C8 4 C1, C9 0 TP1-TP8 8 KEYSTONE 5002 CONN-MINI TEST POINT, VERTICAL, WHITE, ROHS BAN1-BAN4 4 KEYSTONE 575-4 CONN-JACK, MINI BANANA, 0.175 PLUG, NICKEL/BRASS, ROHS J1 1 BERG/FCI 68000-236HLF CONN-HEADER, 1x8, BRKAWY 1x36, 2.54mm, ROHS J1-Pins 5-6 1 SULLINS SPC02SYAN CONN-JUMPER, SHORTING, 2PIN, BLACK, GOLD, ROHS LED1 1 LITEON/VISHAY LTST-C190KGKT LED, SMD, 0603, GREEN CLEAR, 2V, 20mA, 571nm, 35mcd, ROHS U1 1 INTERSIL ISL8205MIRZ IC-5A PWR MODULE, ANALOG DC/DC, 22P, QFN, 4.5x7.5, ROHS Q1 1 DIODES, INC. 2N7002-7-F TRANSISTOR, N-CHANNEL, 3LD, SOT-23, 60V, 115mA, ROHS R12 1 TE CONNECTIVITY 3-1879216-2 RES, SMD, 0402, 150k, 1/16W, 0.1%, TF, ROHS R9 1 TE CONNECTIVITY 6-1879215-6 RES, SMD, 0402, 22.1k, 1/16W, 0.1%, TF, ROHS R11 1 TE CONNECTIVITY 9-1879208-7 RES, SMD, 0402, 100k, 1/16W, 0.1%, TF, ROHS R4 0 R5, R15 2 VENKEL CR0402-16W-00T RES, SMD, 0402, 0Ω, 1/16W, 5%, TF, ROHS R1 1 ROHM MCR01MZPF2003 RES, SMD, 0402, 200k, 1/16W, 1%, TF, ROHS R2, R6, R16 0 R13 1 VENKEL CR0603-10W-1003FT RES, SMD, 0603, 100k, 1/10W, 1%, TF, ROHS R14 1 KOA RK73H1JTTD2001F RES, SMD, 0603, 2k, 1/10W, 1%, TF, ROHS R3 1 VENKEL CR0603-10W-2003FT RES, SMD, 0603, 200k, 1/10W, 1%, TF, ROHS R7 1 STACKPOLE RNCF0402DTE124K RES, SMD, 0402, 124k, 1/16W, 0.5%, TF, ROHS R10 1 YAGEO RT0402BRD0731K6L RES, SMD, 0402, 31.6k, 1/16W, 0.1%, TF, ROHS SW1 1 ITT INDUSTRIES/C&K DIVISION GT11MSCBE C10 0 CAP, TANT, SMD, 2917, 10V, DNP-PLACE HOLDER C11 0 CAP, TANT POLY, SMD, 2917, 10V, DNP-PLACE HOLDER Submit Document Feedback MANUFACTURER PART NUMBER DESCRIPTION CAP, SMD, 0805, 4.7µF, 10V, 10%, X7R, ROHS CAP, SMD, 0402, DNP-PLACE HOLDER, ROHS TAIYO YUDEN LMK316AB7226KL-TR CAP, SMD, 1206, 22µF, 10V, 10%, X7R, ROHS CAP, SMD, 1206, DNP-PLACE HOLDER, ROHS RES, SMD, 0603, 0.1%, MF, DNP-PLACE HOLDER RES, SMD, 0402, DNP, DNP, DNP, TF, ROHS 7 SWITCH-TOGGLE, SMD, 6PIN, SPDT, 2POS, ON-NONE-ON, ROHS UG072.0 May 3, 2016 User Guide 072 Board Layout FIGURE 11. TOP LAYER (TOP VIEW) FIGURE 12. INNER LAYER 1 (TOP VIEW) FIGURE 13. INNER LAYER 2 (TOP VIEW) FIGURE 14. BOTTOM LAYER (BOTTOM VIEW) Submit Document Feedback 8 UG072.0 May 3, 2016 User Guide 072 ISL8205MEVAL1Z Performance Data The following data was acquired using a ISL8205MEVAL1Z evaluation 100.0 100.0 95.0 95.0 90.0 90.0 EFFICIENCY (%) EFFICIENCY (%) board at +25°C ambient and free air 0LFM. 85.0 80.0 Vout = 1V, Fsw = 1.3MHz 75.0 Vout = 1.2V, Fsw = 1.6MHz 70.0 Vout = 2.5V, Fsw = 2.5MHz 65.0 85.0 80.0 Vout = 1V, Fsw = 1.3MHz 75.0 Vout = 1.2V, Fsw = 1.6MHz 70.0 Vout = 2.5V, Fsw = 2.5MHz Vout = 3.3V, Fsw = 3MHz 65.0 60.0 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 60.0 5 0 0.5 1 100.0 95.0 95.0 90.0 90.0 EFFICIENCY (%) EFFICIENCY (%) 100.0 85.0 80.0 Vout = 1V, Fsw = 1.3MHz Vout = 1.2V, Fsw = 1.6MHz 70.0 Vout = 2.5V, Fsw = 2.5MHz 65.0 2 2.5 3 3.5 4 4.5 5 FIGURE 16. EFFICIENCY TA = +25°C, VIN = 5V PFM MODE FIGURE 15. EFFICIENCY TA = +25°C, VIN = 3.3V PFM MODE 75.0 1.5 LOAD CURRENT (A) LOAD CURRENT (A) 85.0 80.0 Vout = 1V, Fsw = 1.3MHz Vout = 1.2V, Fsw = 1.6MHz Vout = 2.5V, Fsw = 2.5MHz Vout = 3.3V, Fsw = 3MHz 75.0 70.0 65.0 60.0 60.0 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 LOAD CURRENT (A) FIGURE 17. EFFICIENCY TA = +25°C, VIN = 3.3V PWM MODE 0.5 1 1.5 2 2.5 3.5 4 4.5 5 FIGURE 18. EFFICIENCY TA = +25°C, VIN = 5V PWM MODE IOUT 2A/DIV VOUT 50mV/DIV VOUT 50mV/DIV 100µs/DIV 100µs/DIV 9 3 LOAD CURRENT (A) IOUT 2A/DIV FIGURE 19. LOAD TRANSIENT VIN = 5V, VOUT = 1.2V, IOUT = 0 TO 5A, fSW = 1.6MHz, COUT = 2 x 22µF CERAMIC CAPACITORS LOAD CURRENT SLEW RATE: 1A/µs Submit Document Feedback 0 FIGURE 20. LOAD TRANSIENT VIN = 5V, VOUT = 3.3V, IOUT = 0 TO 5A, fSW = 3MHz, COUT = 2 x 22µF CERAMIC CAPACITORS, LOAD CURRENT SLEW RATE: 1A/µs UG072.0 May 3, 2016 User Guide 072 ISL8205MEVAL1Z Performance Data The following data was acquired using a ISL8205MEVAL1Z evaluation board at +25°C ambient and free air 0LFM. (Continued) MAX=50.2°C FIGURE 21. THERMAL IMAGE AT VIN = 5V, VOUT = 1.2V, IOUT = 5A, fSW = 1.6MHz, TA = +25°C, FREE AIR 0 LFM 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 document is current before proceeding. For information regarding Intersil Corporation and its products, see www.intersil.com Submit Document Feedback 10 UG072.0 May 3, 2016