Application Note 1931 ISL85413DEMO1Z, ISL85412DEMO1Z Wide VIN Synchronous Buck Regulator - Short Form Description Key Features The ISL85413DEMO1Z, ISL85412DEMO1Z kit is intended for use for point-of-load applications sourcing from 3.5V to 40V. The kit is used to demonstrate the performance of the ISL85413, ISL85412 Wide VIN Low Quiescent Current High Efficiency Synchronous Buck Regulator with 300mA (ISL85413) and 150mA (ISL85412) output current. • Wide input voltage range 3.5V to 40V The ISL85413, ISL85412 is offered in a 3mmx3mm 8 Ld DFN package with 1mm maximum height. • Continuous output current up to 300mA (ISL85413) and 150mA (ISL85412) Recommended Equipment • Internal soft-start The following materials are recommended to perform testing: • 0V to 50V power supply with at least 2A source current capability • Electronic loads capable of sinking current up to 1.5A • Digital Multimeters (DMMs) • 100MHz quad-trace oscilloscope • Synchronous operation for high efficiency • No compensation required • Integrated high-side and low-side NMOS devices • Selectable PFM or forced PWM mode at light loads • Minimal external components required • Power-good and enable functions available References • ISL85412 Datasheet • ISL85413 Datasheet Ordering Information • Signal generator PART NUMBER DESCRIPTION ISL85412DEMO1Z Demonstration Board (150mA Output Current) ISL85413DEMO1Z Demonstration Board (300mA Output Current) FIGURE 1. FRONT OF EVALUATION BOARD ISL85413DEMO1Z, ISL85412DEMO1Z March 13, 2015 AN1931.1 1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. Copyright Intersil Americas LLC 2014, 2015. 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 1931 Quick Setup Guide Disabling/Enabling Function The ISL85413DEMO1Z, ISL85412DEMO1Z boards have the EN pin tied to VCC via R7. This keeps the part enabled all the time. To disable the part, remove R7 and populate R8 with a 0Ω resistor. 1. Ensure that the circuit is correctly connected to the supply and loads prior to applying any power. 2. Connect the bias supply to VIN, the plus terminal to VIN (P4) and the negative return to GND (P5). MODE Control The ISL85413 and ISL85412 evaluation boards have a MODE pin that allows different mode operation. The 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 PFM mode. 3. Turn on the power supply. 4. Verify the output voltage is 3.3V for VOUT. Evaluating the Other Output Voltage The ISL85413DEMO1Z, ISL85412DEMO1Z kit output is preset to 3.3V; however, output voltages can be adjusted from 0.6V to 15V. Please refer to application note AN1929 and ISL85412 datasheet for further information. R1 90.9K 2 U1 MODE BOOT C3 VIN P9 1 1 1 C5 C6 OPEN 0.1UF L1 33UH PHASE 2 22UF 8 2 7 7 3 ISL85413 6 6 4 4 5 5 9 EP 2 3 1 FB VCC PG EN 1 330PF VO 2 2 R2 20K C9 1UF 1 L8.3X3H 2 1 1 VO C2 10UF 2 2 P5 C1 10UF 2 C10 150UF 1 1 P7 1 1 2 P4 8 1 1 C4 A A 1 A VCC 2 VIN R6 200K R7 1 200K MODE EN P2 2 P1 1 1 PG 2 R8 R9 OPEN OPEN 1 1 A A 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. FIGURE 2. ISL85413DEMO1Z AND ISL85412DEMO1Z SCHEMATIC Submit Document Feedback 2 AN1931.1 March 13, 2015 Application Note 1931 ISL85413DEMO1Z Board Layout FIGURE 3. SILKSCREEN TOP FIGURE 4. SILKSCREEN BOTTOM 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 3 AN1931.1 March 13, 2015