Application Note 1935 ISL85003DEMO1Z, ISL85003ADEMO1Z Evaluation Board User Guide Description Quick Setup Guide The ISL85003 and ISL85003A Demo kits are intended for use for point-of-load applications sourcing from 4.5V to 18V. The kits are used to demonstrate the performance of the ISL85003 and ISL85003A, high efficiency synchronous buck regulators. The ISL85003 and ISL85003A are offered in a 4x3mm dual flat no lead (DFN) package. 1. Ensure that the circuit is correctly connected to the supply and loads prior to applying any power. Recommended Equipment 4. Verify the output voltage is 5V for VOUT. The following materials are recommended to perform testing: • 0V to 25V power supply with at least 10A source current capability • Electronic loads capable of sinking current up to 7A • Digital Multimeters (DMMs) • 100MHz quad-trace oscilloscope 3. Turn on the power supply. Evaluating the Other Output Voltage The ISL85003DEMO1Z kit output is preset to 5V; however, output voltages are programmed using an external resistor divider that scales the feedback relative to the internal reference voltage. Please refer to the application note AN1930 and the ISL85003, ISL85003A datasheet for further information. Disabling/Enabling Function Key Features The ISL85003DEMO1Z board has EN pin tied to VIN via R7. This keeps the part enabled all the time. To disable the part, remove R7. • Input voltage range 4.5V to 18V • Current mode control - 2. Connect the bias supply to VIN, the plus terminal to VIN and the negative return to PGND. DCM/PWM Internal or external compensation options 500kHz switching frequency option External synchronization up to 2MHz on ISL85003 • Adjustable soft-start time on the ISL85003A • Continuous output current up to 3A • Minimal external components required References MODE/SS Control The ISL85OO3 evaluation board has a MODE pin that allows different mode operation. Default board configuration has R6 = 200k to VCC, which defaults to PWM operation mode. If this pin is tied to GND the IC will operate in CCM mode. The ISL85OO3A evaluation board has an SS pin that provides a programmable soft-start. When the chip is enabled, the regulated 4μA pull-up current source charges a capacitor C10 connected from SS to ground. Default board configuration has R6 = 200k to VCC, which defaults to internal SS. ISL85003, ISL85003A Datasheet Ordering Information PART NUMBER DESCRIPTION ISL85003DEMO1Z Small form factor Demo board for 3A, 4.5V to 18V Switching Regulator, external synchronization. ISL85003ADEMO1Z Small form factor Demo board for 3A, 4.5V to 18V Switching Regulator, adjustable soft-start time TOP SIDE BOTTOM SIDE FIGURE 1. ISL85003ADEMO1Z PICTURES May 16, 2014 AN1935.0 1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. Copyright Intersil Americas LLC 2014. All Rights Reserved. 1-888-INTERSIL or 1-888-468-3774 | 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. Application Note 1935 ISL85003ADEMO1Z Board Layout FIGURE 3. SILK SCREEN BOTTOM FIGURE 2. SILK SCREEN TOP ISL85003ADEMO1Z Schematic D2 U1 BOOT SS PG VO EN R1 C7 301K DNP R3 UNNAMED_1_SMCAP_I186_A C4 C8 UNNAMED_1_SMCAP_I185_A 4.7PF DNP 1 SS BOOT 12 2 PG VDD 11 3 EN/SS VIN 10 4 FB VIN 9 5 COMP PHASE 8 6 AGND PHASE 7 13 UNNAMED_1_SMCAP_I193_A DNP 1 3 VO 2 VCC VCC P4 VIN C9 C2 1UF 10UF C1 10UF P5 GND C3 EP 0.1UF A R11 0 L1 ISL85003AFRZ R2 P7 VO UNNAMED_1_POWERIND_I179_A VO 4.7UH 57.6K C5 22UF A A C6 C11 22UF 22UF P9 GND VCC VCC VIN SS R7 200K R14 PG 200K R6 200K VCC A EN NOTE: If the IC is used in an application where the input test leads have large parasitic inductance, the input electrolytic capacitor C10 may be added to prevent transient voltages on the input pin. C10 OPEN DRAWN BY: A Submit Document Feedback 2 TU BUI DATE: 2/27/2014 ENGINEER: TU BUI DA AN1935.0 May 16, 2014 Application Note 1935 ISL85003DEMO1Z, ISL85003ADEMO1Z Bill of Materials QTY UNIT S REFERENCE DESIGNATOR ISL85003FRZ 1 ea. U1 IC-3A BUCK REGULATOR, 12P, DFN, 4X3, ROHS ISL85003AFRZ 1 ea. U1 IC-3A BUCK REGULATOR PWM, 12P, INTERSIL DFN, 4X3, ROHS ISL85003AFRZ H1044-00104-50V10-T 1 ea. C3 CAP, SMD, 0402, 0.1µF, 50V, 10%, X7R, ROHS TDK C1005X7R1H104K H1044-004R7-50VR25-T 1 ea. C4 CAP, SMD, 0402, 4.7PF, 50V, 0.25pF, AVX NPO, ROHS 04025A4R7CAT2A H1044-DNP 0 ea. C7, C10 H1045-00105-16V10-T 1 ea. C9 H1065-00106-25V10-T 2 ea. H1065-00226-16V10-T 3 744311470 PART NUMBER DESCRIPTION MANUFACTURER INTERSIL MANUFACTURER PART ISL85003FRZ CAP, SMD, 0402, DNP-PLACE HOLDER, ROHS CAP, SMD, 0603, 1µF, 16V, 10%, X5R, ROHS MURATA GRM188R61C105KA12D C1, C2 CAP, SMD, 1206, 10µF, 25V, 10%, X7R, ROHS VENKEL C1206X7R250-106KNE ea. C5, C6, C11 CAP, SMD, 1206, 22µF, 16V, 10%, X5R, ROHS VENKEL C1206X5R160-226KNE 1 ea. L1 COIL-PWR CHOKE, SMD, 7X6.9, 4.7µH, 20%, 6A, 19.5mΩ, ROHS WURTH ELECTRONICS 744311470 MIDCOM INC. BAT54C-T 1 ea. D2 DIODE-RECTIFIER, SMD, SOT23, 3P, 30V, 200mA, ROHS FAIRCHILD H2510-00R00-1/16W-T 1 ea. R11 RES, SMD, 0402, 0Ω, 1/16W, 5%, TF, VENKEL ROHS CR0402-16W-00T H2510-02003-1/16W1-T 3 ea. R6, R7, R14 RES, SMD, 0402, 200k, 1/16W, 1%, ROHM TF, ROHS MCR01MZPF2003 H2510-03013-1/16W1-T 1 ea. R1 RES, SMD, 0402, 301k, 1/16W, 1%, YAGEO TF, ROHS RC0402FR-07301KL H2510-05762-1/16W1-T 1 ea. R2 RES, SMD, 0402, 57.6k, 1/16W, 1%, PANASONIC TF, ROHS ERJ-2RKF5762X BAT54C 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 3 AN1935.0 May 16, 2014