ISL8500EVAL1Z 2A Regulator Standard Buck PWM ® Application Note November 21, 2007 AN1372.0 Description Recommended Equipment The ISL8500EVAL1Z REV A kit is intended for use by individuals with requirements for Point-of-Load applications sourcing from 4.5V to 25V. The ISL8500EVAL1Z evaluation board is used to demonstrate the performance of the ISL8500 standard buck regulator. The following materials are recommended to perform testing: The ISL8500 is offered in a 4mmx3mm 12 Ld DFN package with 1mm maximum height. The complete converter occupies less than 0.425in2 area. • 0V to 25V power supply with at least 5A source current capability, battery, notebook AC adapter • One electronic load capable of sinking current up to 5A • Digital Multimeters (DMMs) • 100MHz quad-trace oscilloscope Features • Signal generator • Standard Buck Controller with Integrated Switching Power MOSFET Quick Setup Guide • Integrated Boot Diode 1. Ensure that the circuit is correctly connected to the supply and loads prior to applying any power. • Input Voltage Range - Fixed 5V ±10% - Variable 5.5V to 25V 2. Connect the bias supply to VIN, the plus terminal to TP1 (VIN) and the negative return to TP2 (GND). • PWM Output Voltage Adjustable from 0.6V to 20V with Continuous Output Current up to 2A 4. Turn on the power supply. 3. Verify that SW1 is on ENABLE. • Voltage Mode Control with Voltage Feed Forward 5. Verify the PG is on and the output voltage is 2.5V for VOUT(TP3). Evaluating the Other Output Voltage • Fixed 500kHz Switching Frequency The ISL8500EVAL kit outputs are preset to 2.5V; however, it can be programmed using resistor dividers using Equation 1: • Externally Adjustable Soft-Start Time • Output Undervoltage Protection R 1 ⋅ 0.6V R 2 = ---------------------------------V OUT – 0.6V • PGOOD Output (EQ. 1) • Overcurrent Protection The output voltage programming resistor R2 will depend on on the feedback resistor R1, as referred to in Figure 1. The value of R1 is typically between 1kΩ and 10kΩ. If the output voltage desired is 0.6V, then R2 is left opened. • Thermal Overload Protection • Internal 5V LDO regulator Applications VOUT • General Purpose R1 • WLAN Cards-PCMCIA, Cardbus32, MiniPCI CardsCompact Flash Cards + EA • Hand-Held Instruments R2 0.6V REFERENCE What’s Inside The Evaluation Board Kit contains the following materials: FIGURE 1. EXTERNAL RESISTOR DIVIDER • The ISL8500 EVAL REV D board • The ISL8500 datasheet TABLE 1. SWITCH 1 SETTINGS • This EVAL KIT document SW1 1 1 ENABLE SW1 OPERATING MODE Enable or disable the buck controller 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. 2007. All Rights Reserved All other trademarks mentioned are the property of their respective owners. Schematic 1 R2 2200PF C2 10K 1 1 220UF C20 2 1 2 0.1UF 7 4 SP2 2 TP13 1 R12 100K VDD ON 3 SW1 1 OFF 2 EN 1 2 4 SP1 1 ISL8500IRZ R30 1 C9 BOOT 3 8 C8 13 TP3 9 C21 6 VOUT 1 OPEN 5 L1 10UH PHASE 2 4 10 100UF EN PG 11 2 C13 1 3 TP2 2 C12 1 0.1UF 1 GND 12 3 2 C4 VIN VIN PHASE PHASE BOOT VDD 1 VIN OPEN POPULATE R30 IF VIN <6V ONLY TP4 Application Note 1326 2 FB COMP SS EN PG GND EP 1 1 2 TP1 1 1 U1 FB COMP 3 PG 2N7002 2 C10 1 3.16K TP16 VIN 2 D3 1 OPEN 2 1 C3 470PF R4 1 Q4 2 301 D1 R3 10PF 10UF C11 10K C1 2 2 R21 R1 51.1K 1UF 2.43K R20 VDD AN1372.0 November 21, 2007 Application Note 1326 ISL8500EVAL1Z Bill of Materials PART NUMBER REFERENCE QTY UNITS DESIGNATOR ISL8500EVAL1ZREVAPCB 1 ea H1044-00222-50V10-T 1 ea H1065-00106-25V10-T 1 ea DNP 0 ea H1082-00107-6R3V20-T 1 ea DESCRIPTION MANUFACTURER MANUFACTURER PART PWB-PCB, ISL8500EVAL1Z, TITAN REVA, ROHS ISL8500EVAL1ZREVAPCB C1 CAP, SMD, 0402, 2200pF, 50V, 10%, X7R, ROHS PANASONIC ECJ-0EB1H222K C10 CAP, SMD, 1206, 10µF, 25V, 10%, X5R, ROHS VENKEL C1206X5R250-106KNE TDK C3225X5R0J107M PANASONIC ECJ-4YB0J107M AVX 12106D107MAT C11, C13, C20, DO NOT POPULATE OR C21 PURCHASE C12 CAP, SMD, 1210, 100µF, 6.3V, 20%, X5R, ROHS H1044-00100-50V5-T 1 ea C2 CAP, SMD ,0402, 10pF, 50V, 5%, NPO ,ROHS VENKEL C0402COG500-100JNE H1044-00471-50V10-T 1 ea C3 CAP, SMD, 0402, 470pF, 50V, 10%, X7R, ROHS PANASONIC ECJ-0EB1H471K VENKEL C0402X74500-471KNE H1044-00104-16V10-T 1 ea C4 CAP, SMD, 0402, 0.1µF, 16V, MURATA 10%, X7R, ROHS VENKEL GRM36X7R104K016AD C0402X7R160-104KNE H1045-00105-6R3V10-T 1 ea C8 CAP, SMD, 0603, 1µF, 6.3V, 10%, X5R, ROHS PANASONIC ECJ1VB0J105K C1608X7R1H104K-T 1 ea C9 CAPACITOR, SMD, 0603, 0.10µF, 50V, 10%, X7R TDK C1608X7R1H104K B340LB-13-F-T 1 ea D1 DIODE-SCHOTTKY SMD, SMB, 2P, 40V, 3A LOW VF, ROHS DIODES INC. B340LB-13-F LTST-C170CKT 1 ea D3 LED-GaAs RED, SMD, 2x1.25mm, 100mW, 40mA, 10mcd, ROHS LITEON/VISHAY LTST-C170CKT ROHM SML-210LTT86 STANLEY ELECTRIC BR112H-TR VISHAY IHLP2525CZRZ100M01 IHLP2525CZRZ100M01 1 ea L1 COIL-PWR INDUCTOR, SMD, 6.9x6.5, 10µH, 20%, 3A, ROHS 2N7002-7-F-T 1 ea Q4 TRANSISTOR,N-CHANNEL, DIODES, INC. 3LD, SOT-23, 60V, 115mA, ON ROHS SEMICONDUCTOR 2N7002-7-F RES, SMD, 0402, 51.1k, 1/16W, 1%, TF, ROHS PANASONIC ERJ-2RKF5112X VENKEL CR0402-16W-5112FT H2510-05112-1/16W1-T 1 ea R1 2N7002LT1G H2510-01003-1/16W1-T 1 ea R12 RES, SMD, 0402, 100k, 1/16W, 1%, TF,ROHS PANASONIC ERJ2RKF1003 H2510-01002-1/16W1-T 1 ea R2 RES, SMD, 0402, 10k, 1/16W, 1%, TF,ROHS PANASONIC ERJ-2RKF1002 VENKEL CR0402-16W-1002FT RES, SMD, 0603, 2.43k, 1/10W, 1%, TF, ROHS VENKEL CR0603-10W-2431FT YAGEO RC0603FR-072K43L RES, SMD, 0603, 10k, 1/10W, 1%, TF,ROHS KOA RK73H1JT1002F VENKEL CR0603-10W-1002FT H2511-02431-1/10W1-T H2511-01002-1/10W1-T 1 ea 1 ea 3 R20 R21 AN1372.0 November 21, 2007 Application Note 1326 ISL8500EVAL1Z Bill of Materials (Continued) PART NUMBER H2510-03010-1/16W1-T REFERENCE QTY UNITS DESIGNATOR 1 ea R3 DESCRIPTION RES, SMD, 0402, 301Ω, 1/16W, 1%, TF, ROHS H2511-DNP 0 ea R30 RES, SMD, 0603, DNPPLACE HOLDER, ROHS H2510-03161-1/16W1-T 1 ea R4 RES,SMD, 0402, 3.16k, 1/16W, 1%, TF, ROHS MANUFACTURER MANUFACTURER PART PANASONIC ERJ-2RKF3010X VENKEL CR0402-16W-3010-FT VENKEL CR0402-16W-3161FT PANASONIC ERJ-2RKF3161X VISHAY/DALE CRCW04023K16FKED 131-4353-00 131-4353-00 2 ea SP1,SP2 CONN-SCOPE PROBE TEST PT, COMPACT, PCB MNT, ROHS TEKTRONIX GT11MSCBE-T 1 ea SW1 SWITCH-TOGGLE, SMD, ULTRAMINI, 1P, SPST MINI C&K COMPONENTS GT11MSCKE 5002 2 ea TP13,TP16 CONN-MINI TEST POINT, VERTICAL, WHITE, ROHS KEYSTONE 1514-2 4 ea TP1-TP4 ISL8500IRZ 1 ea U1 4 5002 CONN-TURRET, TERMINAL KEYSTONE POST, TH, ROHS 1514-2 IC-2A BUCK REGULATOR, 12P, DFN, 4x3, ROHS ISL8500IRZ INTERSIL AN1372.0 November 21, 2007 Application Note 1326 ISL8500EVAL1Z Board Layout FIGURE 2. TOP COMPONENTS FIGURE 3. TOP LAYER ETCH 5 AN1372.0 November 21, 2007 Application Note 1326 ISL8500EVAL1Z Board Layout (Continued) FIGURE 4. BOTTOM LAYER COMPONENTS (MIRRORED) FIGURE 5. BOTTOM LAYER ETCH (MIRRORED) 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 6 AN1372.0 November 21, 2007