Application Note 1606 Author: Jun Xiao ISL8033EVAL1Z Dual 3A Low Quiescent Current High Efficiency Synchronous Buck Regulator Description Quick Setup Guide The ISL8033EVAL1Z kit is intended for use by individuals with requirements for Point-of-Load applications sourcing from 2.85V to 6V. The ISL8033EVAL1Z evaluation board is used to demonstrate the performance of the ISL8033 low quiescent current mode converter. The ISL8033 is offered in a 4mmx4mm 24 Ld QFN package with 1mm maximum height. The complete converter occupies less than 5.46cm2 area. 1. Ensure that the circuit is correctly connected to the supply and loads prior to applying any power. 2. Connect the bias supply to VIN1, the plus terminal to VIN1 and the negative return to PGND1. 3. Verify that position is ON for SW2 and SW3. 4. Turn on the power supply. 5. Verify the output voltage is 1.8V for VOUT1 and 1.8V for VOUT2. Evaluating the Other Output Voltage Key Features • Dual 3A High Efficiency Synchronous Buck Regulator with up to 95% Efficiency • 180° Out-of-Phase • Power-Goods (PG) Output with 1ms Delay • 2.85V to 6V Supply Voltage • 2% Output Accuracy Over-temperature/Load/Line • Start-up with Pre-biased Output • Internal Digital Soft-Start - 1.5ms • Soft-Stop Output Discharge During Disabled • External Synchronization up to 6MHz • Typical 8µA 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 Recommended Equipment The following materials are recommended to perform testing: • 0V to 10V Power Supply with at least 3A source current capability or 5V battery The ISL8033EVAL1Z kit output is preset to 1.8V for VOUT1 and 1.8V for VOUT2; however, output voltages can be adjusted from 0.8V to 3.3V. The output voltage programming resistor, R2 (or R5 in Channel 2), will depend on the desired output voltage of the regulator. The value for the feedback resistor is typically between 0Ω and 750kΩ as shown in Equation 1. Let’s set R3/R6 = 100kΩ, then R2/R5 will be: VOUT R2 = R3 ⎛ ------------------ – 1⎞ ⎝ VFB ⎠ (EQ. 1) If the output voltage desired is 0.8V, then R3 is left unpopulated and short R2. For faster response performance, add 47pF in parallel to R2. Mode Control The ISL8033 has a SYNC pin. Connects to logic high or input voltage VIN for PWM internal synchronization. Connect to an external function generator for external Synchronization. Negative edge trigger. Do not leave this pin floating. Do not tie this pin low (or to GND). TABLE 1. SWITCH SETTINGS SW2, SW3 ENABLE ON/OFF CONTROL 1 OFF Disable VOUT 3 ON Enable VOUT • Electronic Loads capable of sinking current up to 3A • Digital Multimeters (DMMs) • 100MHz quad-trace oscilloscope • Signal generator October 27, 2010 AN1606.0 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. ISL8033EVAL1Z Schematic 2 Application Note 1606 AN1606.0 October 27, 2010 Application Note 1606 TABLE 2. BILL OF MATERIALS PART NUMBER QTY UNITS REFERENCE DESIGNATOR DESCRIPTION MANUFACTURER MANUFACTURER PART ISL8033_36EVAL1ZREVAPCB 1 ea PWB-PCB, a) PUT “X” IN ISL8033 BOX ON ISL8033_36EVAL1Z, REVA, ROHS PCB IMAGINEERING INC. ISL8033_36EVAL1ZREVA PCB ISL8033_36EVAL1ZREVAPCB 0 ea b) SEE LABEL-RENAME BOARD PWB-PCB, ISL8033_36EVAL1Z, REVA, ROHS IMAGINEERING INC. ISL8033_36EVAL1ZREVA PCB C2012X5R0J226M-T 6 ea C3, C4, C9, C11, CAP, SMD, 0805, 22µF, TDK CIN1, CIN2 6.3V, 20%, X5R, ROHS C2012X5R0J226M H1045-00120-50V5-T 2 ea C5, C10 06035A120JAT2A H1045-DNP 0 ea C1, C2, C8, CD1, CAP, SMD, 0603, CD2, CDC, C_PH DNP-PLACE HOLDER, ROHS H1046-DNP 0 ea C6, C7 CAP, SMD, 0805, DNP-PLACE HOLDER, ROHS DR73-1R5-R (ISL8033) 2 ea L1, L2 DR73-1R5-R COIL-PWR INDUCTOR, COOPER SMD, 7.5mm, 1.5µH, ELECTRONIC TECH 20%, 6.52A, ROHS FDV0630-R60M (ISL8033A) 2 ea L1, L2 Iron Powder Inductor, SMD, 7.4X6.7mm, 0.6µH, 20%, 10A, ROHS TOKO FDV0630-R60M 131-4353-00 4 ea LX1, LX2, VOUT1_S, VOUT2_S CONN-SCOPE PROBE TEST PT, COMPACT, PCB MNT, ROHS TEKTRONIX 131-4353-00 1514-2 8 ea CONN-TURRET, a) PGND1, PGND2, PGND11, TERMINAL POST, TH, PGND22, VIN1, ROHS VIN2 KEYSTONE 1514-2 1514-2 0 ea b) VOUT1, VOUT2 CONN-TURRET, TERMINAL POST, TH, ROHS KEYSTONE 1514-2 5000 6 ea a) EN1, EN2, PG1, PG2, SS, SYNC CONN-MINI TEST PT, KEYSTONE VERTICAL, RED, ROHS 5000 5000 0 ea b) SYNC located CONN-MINI TEST PT, KEYSTONE left of C_PH VERTICAL, RED, ROHS 5000 5001 1 ea SGND CONN-MINI TEST PT, KEYSTONE VERTICAL, BLK, ROHS 5001 5002 2 ea COMP, FB CONN-MINI TEST PT, VERTICAL, WHITE, ROHS KEYSTONE 5002 LTST-C170CKT 2 ea D1, D2 LED-GaAs RED, SMD, 2mmX1.25mm, 100mW, 40mA, 10mcd, ROHS LITEON/VISHAY LTST-C170CKT ISL8033IRZ 1 ea U1 INTERSIL IC-DUAL 3A BUCK REGULATOR, 24P, QFN, 4X4, ROHS 3 CAP, SMD, 0603, 12pF, AVX 50V, 5%, COG, ROHS ISL8033IRZ AN1606.0 October 27, 2010 Application Note 1606 TABLE 2. BILL OF MATERIALS (Continued) PART NUMBER QTY UNITS REFERENCE DESIGNATOR DESCRIPTION MANUFACTURER MANUFACTURER PART DIODES, INC. 2N7002-7-F VENKEL CR0603-10W-000T 2N7002-7-F-T 2 ea Q1, Q2 TRANSISTOR, N-CHANNEL, 3LD, SOT-23, 60V, 115mA, ROHS H2509-DNP 1 ea R9 RES, SMD, 0201, 0Ω, 1/20W, 0%, TF H2511-00R00-1/10W-T 4 ea R2, R5, R13, R_PH RES, SMD, 0603, 0Ω, 1/10W, TF, ROHS H2511-01003-1/10W1-T 5 ea R1, R4, R6, RF11, RES, SMD, 0603, 100k, RF21 1/10W, 1%, TF, ROHS H2511-01243-1/10W1-T 2 ea RF12, RF22 RES, SMD, 0603, 124k, YAGEO 1/10W, 1%, TF, ROHS 9C06031A1243FKHFT H2511-02001-1/10W1-T 2 ea R8, R12 RES, SMD, 0603, 2k, KOA 1/10W, 1%, TF, ROHS RK73H1JTTD2001F H2511-DNP 0 ea R3, R7, R11, R10, RES, SMD, 0603, R14 DNP-PLACE HOLDER, ROHS H2514-00R00-1/4W-T 1 ea R_IN RES, SMD, 1210, 0Ω, 1/4W, TF, ROHS H2514-DNP 0 ea R_OUT RES, SMD, 1210, DNP, DNP, DNP, TF, ROHS GT11MSCBE-T 3 ea S1-S3 SJ-5003-BLACK 4 ea Bottom four corners 5X8-STATIC-BAG 1 ea Place assy in bag BAG, STATIC, 5X8, ZIP INTERSIL LOC 212403-013 LABEL-RENAME BOARD 1 ea RENAME PCB TO: LABEL, TO RENAME ISL8033EVAL1Z BOARD LABEL-RENAME BOARD LABEL-SERIAL NUMBER 1 ea 4 VENKEL CR1210-4W-000 SWITCH-TOGGLE, SMD, 6PIN, SPDT, 2POS, ON-ON, ROHS ITT INDUSTRIES/C&K DIVISION GT11MSCBE BUMPONS, 0.44inW x 0.20inH, DOMETOP, BLACK 3M SJ-5003SPBL INTERSIL LABEL, FOR SERIAL NUMBER AND BOM REV # AN1606.0 October 27, 2010 Application Note 1606 ISL8033EVAL1Z Board Layout FIGURE 1. TOP COMPONENTS FIGURE 2. TOP LAYER ETCH FIGURE 3. 2ND LAYER ETCH FIGURE 4. 3RD LAYER ETCH 5 AN1606.0 October 27, 2010 Application Note 1606 ISL8033EVAL1Z Board Layout (Continued) FIGURE 5. BOTTOM LAYER ETCH FIGURE 6. BOTTOM COMPONENTS (MIRROR) 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 AN1606.0 October 27, 2010