ISL8510EVAL1Z 1A Buck Regulator with Integrated MOSFETs ® Application Note The ISL8510 is a high-performance, triple output controller that provides a single, high frequency power solution for a variety of point of load applications. The ISL8510 integrates a 1A standard buck PWM controller and switching MOSFET with one 500mA LDO. The PWM controller in the ISL8510 drives an internal switching N-Channel power MOSFET and requires an external Schottky diode to generate an output voltage from 0.6V to 20V. The integrated power switch is optimized for excellent thermal performance up to 1A of output current. The standard buck input voltage range supports a fixed 5V or variable 6V to 25V range. The PWM regulator switches at a fixed frequency of 500kHz and utilizes simple voltage mode control with input voltage feed forward to provide flexibility in component selection and minimize solution size. Protection features include overcurrent, undervoltage, and thermal overload protection integrated into the IC. The ISL8510 power good signal output indicates loss of regulation on the PWM output. The ISL8510 features adjustable LDO regulator using internal PMOS transistors as pass devices. Enable pin (EN_LDO) control LDO output. A single power good signal output indicates loss of regulation on the LDO output. Independent overcurrent and thermal fault shutdown monitor are integrated into the LDO section. July 10 , 2007 AN1332.0 Features • Standard Buck Controller with Integrated Switching Power MOSFET + 1 LDO • Integrated Boot Diode • Input Voltage Range - Fixed 5V ±10% - Variable 6V to 25V • PWM Output Voltage Adjustable from 0.6V to 20V with Continuous Output Current up to 1A • Voltage Mode Control with Voltage Feed Forward • Fixed 500kHz Switching Frequency • Externally Adjustable Soft-Start Time • Output Undervoltage Protection • LDO Adjustable Options - LDO1, 0.6V to 4.2V . . . . . . . . . . . . . . . . . . . . . . 500mA • Individual Enable Inputs • Two PGOOD Outputs (PWM and LDO) • Overcurrent Protection • Thermal Overload Protection • Internal 5V LDO regulator • Pb-Free Plus Anneal Available (RoHS Compliant) ISL8510 is available in a small 4mmx4mm thin Quad Flat No-Lead (QFN) package. Applications Ordering Information • WLAN Cards-PCMCIA, Cardbus32, MiniPCI CardsCompact Flash Cards Pinout 24 23 EN 20 19 18 VIN VOUT1 2 17 VIN VIN_LDO1 3 16 PHASE 25 GND VIN_LDO2 4 15 PHASE 14 BOOT FB_LDO2 6 13 PVCC CC2 8 9 10 11 EN_LDO2 VOUT2 5 7 1 22 21 FB_LDO1 1 12 VCC NOTE: Intersil Pb-free plus anneal products employ special Pb-free material sets; molding compounds/die attach materials and 100% matte tin plate termination finish, which are RoHS compliant and compatible with both SnPb and Pb-free soldering operations. Intersil Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020. CC1 *Add “-T” suffix for tape and reel SS ISL8510 (24 LD QFN) TOP VIEW GND -40 to +85 24 Ld QFN 4x4 L24.4x4D (2.7 Sq. mm Pad) • Hand-Held Instruments COMP PKG. DWG. # FB_PWM PACKAGE PG_PWM ISL8510IRZ* 85 10IRZ TEMP. RANGE (°C) PG_LDO PART MARKING EN_LDO1 PART NUMBER • General Purpose 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. Application Note 1332 What’s Inside Evaluating the Other Output Voltage The Evaluation Board Kit contains the following materials: The ISL8510EVAL1Z kit outputs are preset to 3.3V, 1.2V, 1.8V; however, all of them can be programmed using resistor dividers using Equation 1: • The ISL8510 EVAL REV D board R 1 ⋅ 0.6V R 2 = ---------------------------------V OUT – 0.6V • The ISL8510 datasheet • This EVAL KIT document Recommended Equipment The following materials are recommended to perform testing: • 0V to 25V power supply with at least 5A source current capability, battery, notebook AC adapter (EQ. 1) The output voltage programming resistor R2 will depend 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. VOUT • Two electronic loads capable of sinking current up to 5A R1 • Digital Multimeters (DMMs) + EA • 100MHz quad-trace oscilloscope • Signal generator R2 0.6V REFERENCE Quick Setup Guide 1. Ensure that the circuit is correctly connected to the supply and loads prior to applying any power. FIGURE 1. EXTERNAL RESISTOR DIVIDER 2. Connect the bias supply to VIN, the plus terminal to TP1 (VCC) and the negative return to TP6 (GND). 3. Verify that SW1 is on ENABLE. TABLE 1. SWITCH 1 SETTINGS SW1 ENABLE OPERATING MODE 4. Turn on the power supply. 1 SW1 Enable or disable the buck controller 5. Verify the PG_PWM LED is on and that the output voltage is 3.3V for VOUT1 (TP3). 2 SW2 Enable or disable LDO1 6. Turn on SW2 to ENABLE. If VLDO1 is connected to a separate power supply, remove R25 from the bottom first, then turn on SW2. 7. Verify the PG_LDO LED is on and LDO output voltage is 1.2V for VOUT2 (TP7). 2 AN1332.0 July 10 , 2007 iSL8510EVAL1Z Schematic VCC R29 R4 2.21K 0 20K 10K 1 0.01UF C2 2 R3 1 3 2N7002 R15 1 10K 1 1UF C7 2 EN_LDO1 EN_LDO2 R27 OPEN EN_LDO2 Q3 ROHS COMPLIANT C14 1 C21 SP1 3 4 5 1 C12 2 100UF C13 1 2 10UF 2 TP12 VCC 10UF 2 TP11 C8 1 VIN OPEN 1 1 1 2 12 GND 11 10 9 8 7 C6 CC2 R9 R30 TP3 2 COMBINE INDUCTOR FOOTPRINTS 10 2 2 C19 1SW3 1000PF 3 0.1UF R5 1 TP15 R16 2 Q2 100K 1 PG_LDO 1 EN_LDO1 2N7002 C18 10K C9 BOOT 13 VOUT1 1 10UH POPULATE R30 IF VIN <6V ONLY 1000PF 1SW2 14 VCC R13 2 0.1UF C16 2 GND 3 3 22UF 3 1 Q1 2 1000PF 10K C17 1 EP 1 25 1 R12 1 2N7002 R11 CC2 PG_LDO EN_LDO1 EN_LDO2 GND VCC PVCC TP13 BOOT 0 100K R10 0 4 100UH L2 15 PHASE R26 1 OPEN R25 D1 VCC PHASE 1 16 D2 L1 17 VIN PHASE 2 OPEN 2 1 VOUT1 3 2 C11 2 18 1 VLDO 3 100UH R28 OPEN 1UF FB_LDO1 VCC 10UF 1 1 SS C4 19 FB COMP 21 24 L1 1 TP7 1 TP6 TP2 1 VOUT2 TP17 VLDO 1 GND GND 1 CC1 5.11K 2 2 PG_LDO 1 VLDO TP5 TP1 TP4 Application Note 1332 0 R6 1 +1.2V C15 1 22UF R18 22 2 TP8 3 2N7002 23 0.1UF 1 CC1 C5 R7 GND 0 5.11K PG_PWM R17 C10 3 D4 1 1 TP16 1 Q4 1SW1 1 D3 1 2 R24 3 2N7002 3 C3 1000PF VIN PG_PWM 1 Q5 2 301 2 R21 10K R20 2.43K C1 2 10PF 10K R23 2.43K R2 R1 AN1332.0 July 10 , 2007 Application Note 1332 TABLE 2. COMPONENT LIST REF DES QTY VALUE TOL C5, C6, C9 3 0.10µF 10% 50V SM 0603 C1608X7R1H104K-T TDK CAPACITOR, SMD, 0603, 0.10µF, 50V, 10%, X7R C11 1 10µF 20% 25V SM 1210 C3225X7R1E106M-T TDK CAP, SMD,1210,10µF, 25V, 20%, X7R, ROHS C2 1 10pF 5% 50V SM 0402 H1044-00100-50V5-T VENKEL CAP, SMD, 0402, 10pF, 50V, 5%, NPO, ROHS C3, C17-C19 4 1000pF 10% 50V SM 0402 H1044-00102-50V10-T VENKEL, PANASONIC, MURATA CAP, SMD, 0402, 1000pF, 50V, 10%, X7R, ROHS C1 1 0.01µF 10% 16V SM 0402 H1044-00103-16V10-T NIC COMP CORP, CAP, SMD, 0402, 0.01µF, PHILLIPS, VENKEL, 16V, 10%, X7R, ROHS KEMET C4 1 33000pF 20% 16V SM 0402 H1044-00333-16V8020-T PANASONIC CAP, SMD, 0402, 33000pf, 16V, +80-20%, Y5V, ROHS C14 1 10µF 10% 6.3V SM 0805 H1046-00106-6R3V10-T VENKEL, AVX, MURATA CAP, SMD, 0805, 10µF, 6.3V, 10%, X5R, ROHS C7 1 1µF 10% 50V SM 1206 H1065-00105-50V10-T VENKEL CAP, SMD, 1206, 1µF, 50V, 10%, X7R, ROHS C8 1 DNP 10% 50V SM 1206 H1065-00105-50V10-T VENKEL CAP, SMD, 1206, 1µF, 50V, 10%, X7R, ROHS C13 1 10µF 10% 25V SM 1206 H1065-00106-25V10-T VENKEL CAP, SMD, 1206, 10µF, 25V, 10%, X5R, ROHS C15 1 22µF 10% 6.3V SM 1206 H1065-00226-6R3V10-T MURATA, KEMET, AVX CAP, SMD, 1206, 22µF, 6.3V, 10%, X5R, ROHS C16 1 DNP 10% 6.3V SM 1206 H1065-00226-6R3V10-T MURATA, KEMET, AVX CAP, SMD, 1206, DNP, DNP, DNP, X5R, ROHS C10 1 4.7pF 5.40% 50V SM 1206 H1065-004R7-50VR25-T VENKEL CAP, SMD, 1206, 4.7pF, 50V, 0.25pF, NPO, ROHS C12 1 100µF 20% 6.3V SM 1210 H1082-00107-6R3V20-T GENERIC CAP, SMD, 1210, 100µF, 6.3V, 20%, X5R, ROHS L2 1 10µH 20% 102mΩ 6.9x6.5 DNP (SP1) 0 DNP - - - 131-5031-00 TEKTRONIX CONN-SCOPE PROBE TEST PT, COMPACT, PCB MNT TP1-TP8 8 - - - - 1514-2 KEYSTONE CONN-TURRET, TERMINAL POST, TH, ROHS TP9-TP10 2 DNP - - - 1514-2 KEYSTONE CONN-TURRET, TERMINAL POST, TH, ROHS TP11-TP14, TP16-TP17 6 - - - - 5002 KEYSTONE CONN-MINI TEST POINT, VERTICAL, WHITE, ROHS TP15 1 DNP - - - 5002 KEYSTONE CONN-MINI TEST POINT, VERTICAL, WHITE, ROHS D1 1 - - - - B340LB-13-F-T DIODES INC DIODE-SCHOTTKY, SMD, SMB, 2P, 40V, 3A LOW VF, Pb-free D3, D4 2 - - - - LTST-C170CKT LITEON, VISHAY, ROHM, STANLEY ELECTRIC LED-GaAs RED, SMD, 2mmx1.25mm, 100mW, 40mA, 10mcd, ROHS 4 VOLTAGE PACKAGE PART NUMBER MANUFACTURER IHLP-2525CZ-ER-10R-M01 VISHAY DESCRIPTION COIL-PWR INDUCTOR, SMD, 6.9mmx6.5mm, 10µH, 20%, 3A, ROHS AN1332.0 July 10 , 2007 Application Note 1332 TABLE 2. COMPONENT LIST (Continued) REF DES QTY VALUE TOL U1 1 - - - QFN ISL8510IRZ Q1-Q5 5 - - 60V SOT-23 2N7002-7-F-T R17, R18 2 0Ω 5% 50V SM 0402 H2510-00R00-1/16W-T VENKEL, PANASONIC RES, SMD, 0402, 0Ω, 1/16W, 5%, TF, ROHS R2, R11, R13, R15 4 10k 1% 50V SM 0402 H2510-01002-1/16W1-T PANASONIC, VENKEL RES, SMD, 0402, 10k, 1/16W, 1%, TF, ROHS R12, R14, R16 3 100k 1% 50V SM 0402 H2510-01003-1/16W1-T PANASONIC RES, SMD, 0402, 100k, 1/16W, 1%, TF, ROHS R1 1 20k 1% 50V SM 0402 H2510-02002-1/16W1-T PANASONIC RES, SMD, 0402, 20k, 1/16W, 1%, TF, ROHS R4 1 2.21k 1% 50V SM 0402 H2510-02211-1/16W1-T PANASONIC, VENKEL RES, SMD, 0402, 2.21k, 1/16W, 1%, TF, ROHS R8-R9 2 DNP 1% 50V SM 0402 H2510-02551-1/16W1-T VENKEL, VISHAY, DALE RES, SMD, 0402, DNP, DNP, DNP, TF, ROHS R3 1 301Ω 1% 50V SM 0402 H2510-03010-1/16W1-T PANASONIC, VENKEL RES, SMD, 0402, 301Ω, 1/16W, 1%, TF, ROHS R6-R7 2 5.11k 1% 50V SM 0402 H2510-05111-1/16W1-T PANASONIC RES, SMD, 0402, 5.11k, 1/16W, 1%, TF, ROHS R5, R10, R29 3 0Ω 1% 75V SM 0603 H2511-00R00-1/10W-T GENERIC RESISTOR, SMD, 0603, 0Ω, 1/10W, TF, ROHS R21, R24 2 10k 1% 75V SM 0603 H2511-01002-1/10W1-T KOA, VENKEL RES, SMD, 0603, 10k, 1/10W, 1%, TF, ROHS R20, R23 2 2.43k 1% 75V SM 0603 H2511-02431-1/10W1-T VENKEL, YAGEO RES, SMD, 0603, 2.43k, 1/10W, 1%, TF, ROHS R25 1 0Ω 1% 200V SM 1206 H2513-00R00-1/4W-T VISHAY, VENKEL RES, SMD, 1206, 0Ω, 1/4W, TF, ROHS R26-R28, R30 0 DNP 1% 200V SM 1206 H2513-DNP GENERIC RES, SMD, 1206, DNP, DNP, DNP, TF, ROHS SW1-SW2 2 - - - - GT11MSCBE-T C&K COMPONENTS SWITCH-TOGGLE, SMD, ULTRAMINI, 1P, SPST MINI SW3 1 DNP - - - GT11MSCBE-T C&K COMPONENTS SWITCH-TOGGLE, SMD, ULTRAMINI, 1P, SPST MINI C20, C21 0 DNP - - - DNP DO NOT POPULATE OR PURCHASE D2 0 DNP - - - DNP DO NOT POPULATE OR PURCHASE L1 0 DNP - - - DNP DO NOT POPULATE OR PURCHASE 5 VOLTAGE PACKAGE PART NUMBER MANUFACTURER INTERSIL DESCRIPTION IC-2A BUCK REGULATOR, 24P, QFN, 4x4, ROHS DIODES, INC, ON TRANSISTOR, N-CHANNEL, SEMICONDUCTOR 3 LD, SOT-23, 60V, 115mA, ROHS AN1332.0 July 10 , 2007 Application Note 1332 ISL8510EVAL1Z Board Layout FIGURE 2. TOP COMPONENTS FIGURE 3. TOP LAYER ETCH 6 AN1332.0 July 10 , 2007 Application Note 1332 ISL8510EVAL1Z Board Layout (Continued) FIGURE 4. 2ND LAYER ETCH FIGURE 5. 3RD LAYER ETCH 7 AN1332.0 July 10 , 2007 Application Note 1332 ISL8510EVAL1Z Board Layout (Continued) FIGURE 6. BOTTOM LAYER COMPONENTS (MIRRORED) FIGURE 7. 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 8 AN1332.0 July 10 , 2007