Application Note 1587 Author: Huong Doan ISL8022EVAL2Z Dual 2A/1.7A Low Quiescent Current 2.25MHz High Efficiency Synchronous Buck Regulator Description TABLE 1. BILL OF MATERIALS The ISL8022EVAL2Z kit is intended for use by individuals with requirements for Point-of-Load applications sourcing from 2.8V to 5.5V. The ISL8022EVAL2Z evaluation board is used to demonstrate the performance of the ISL8022 low quiescent current mode converter. The ISL8022 is offered in a 4mmx3mm 12 Ld DFN package with 1mm maximum height. The complete converter occupies less than 0.175in2 area. REFERENCE DESIGNATOR DESCRIPTION Recommended Equipment C2, C4 CAP, SMD, 0805, TDK 22µF, 6.3V, 20%, X5R, ROHS C2012X5R0J226M C1, C8 MURATA CAPACITOR, SMD, 0805, 10µF, 6.3V, 10%, X5R GRM21BR60J106KE01L C6, C7 CAP, SMD, 0805, DNP-PLACE HOLDER, ROHS C3, C5 CAP-RF HIQ, SMD, 0402, 10pF, 50V, 5%, COG, ROHS L1, L2 COIL-PWR TDK INDUCTOR, WW, SMD, 4mm, 1.2µH, 30%, 2.7A, ROHS VLCF4028T-1R2N2R7-2 U1 IC-2A/1.7A BUCK REGULATOR, 12P, DFN, 4X3, ROHS ISL8022IRZ R1, R3, R6 RES, SMD, 0402, PANASONIC ERJ2RKF1003 100k, 1/16W, 1%, TF, ROHS R5 RES, SMD, 0402, ROHM 200k, 1/16W, YAGEO 1%, TF, ROHS VISHAY/ DALE The following materials are recommended to perform testing: • 0V to 10V Power Supply with at least 3A source current capability or 5V battery • Electronic Loads capable of sinking current up to 3A • Digital Multimeters (DMMs) • 100MHz quad-trace oscilloscope • Signal generator MFR PART ISL8022EVAL2ZREVAPCB Key Features • Dual 2A/1.7A High Efficiency Synchronous Buck Regulator with up to 97% Efficiency • 180° Out-of-Phase • Power-Goods (PG) Output with 1ms Delay • 2.8V to 5.5V Supply Voltage • 3% Output Accuracy Over-temperature/Load/Line • Start-up with Pre-biased Output • 40µA Quiescent Supply Current in PFM Mode • Selectable Forced PWM Mode and PFM Mode • External Synchronization up to 8MHz • Typical 6.5µA Logic Controlled Shutdown Current • 100% Maximum Duty Cycle for Lowest Dropout • Internal Current Mode Compensation • Peak Current Limiting, Hiccup Mode Short Circuit Protection and Over-temperature Protection • Negative Current Detection and Protection MFR PWB-PCB, TBD ISL8022EVAL2Z, REVA, ROHS JOHANSON 500R07S100JV4T TECH. INTERSIL VENKEL MCR01MZPF2003 RC0402FR-07200KL CRCW0402200KFKED CR0402-16W-2003FT R2 RES, SMD, 0402, PANASONIC ERJ-2RKF3163X 316k, 1/16W, VENKEL CR0402-16W-3163FT 1%, TF, ROHS R9 RES, SMD, 0402, DNP, DNP, DNP, TF, ROHS Quick Setup Guide 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 and the negative return to P1. 3. Turn on the power supply. 4. Verify the output voltage is 2.5V for VOUT1 and 1.8V for VOUT2. August 10, 2010 AN1587.1 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. 2010. All Rights Reserved All other trademarks mentioned are the property of their respective owners. C8 10UF PWM FIGURE 3. BOTTOM SILK SCREEN FIGURE 2. TOP COMPONENTS R6 100K FIGURE 1. ISL8022EVAL2Z SCHEMATIC A Application Note 1587 A R3 100K A A C5 10PF R5 200K R2 316K P2 2 VOUT2 For information regarding Intersil Corporation and its products, see www.intersil.com 2 AN1587.1 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. R1 100K C3 10PF R9 OPEN C2 22UF C6 OPEN A A PGND1 SYNC C7 OPEN C4 22UF ISL8022IRZ VOUT2 C1 10UF VOUT1 VOUT1 VIN PFM 4 PGND2 PGND1 13 EP L2 8 LX2 1 9 1.2UH 7 6 VOUT1 5 2 LX1 1.2UH L1 1 A SYNC 10 3 P1 FB2 U1 11 2 SYNC VIN2 LX2 PG VIN1 LX1 12 FB2 EN2 1 FB1 EN1 FB1 VIN VIN