Application Note 1584 Author: Paul Orfanu ISL85033EVAL2Z (Small Form) Wide VIN Dual Standard Buck Regulator With 3A/3A Output Current - Long Form Description Key Features The ISL85033EVAL2Z kit demonstrates performance of the ISL85033 switching regulator IC. An input range of 4.5V to 28V and 3A output per channel (connect in parallel to 6A) allows the ISL85033 to meet a wide variety of POL requirements. • Wide Input Voltage Range from 4.5V to 28V The ISL85033 is offered in a 4mmx4mm 28 Ld TQFN package with 1mm maximum height. The complete converter occupies 6.25cm2 area. 100 EFFICIENCY (%) 90 80 • Independent Power-Good Detection • Selectable In-Phase or Out-of-Phase PWMs Switching Operation • Overcurrent and Hiccup Mode Short Circuit Protection, Thermal Overload Protection, UVLO 3.3VOUT 500kHz • Boot Undervoltage Detection • Channels are Out-of-phase, Reducing Voltage Ripple and Component Size 50 1.8VOUT 300kHz 40 0.0 0.5 1.0 1.5 2.0 OUTPUT LOAD (A) • Adjustable Switching Frequency from 300kHz to 2MHz • Internal 2ms Soft-start Time 5VOUT 500kHz 60 • Current Mode Control • Independent, Sequential, Ratiometric or Absolute Tracking Between Outputs 12VOUT 1MHz 9VOUT 1MHz 70 • Adjustable Output Voltage with Continuous Output Current up to 3A per channel 2.5 3.0 FIGURE 1. EFFICIENCY vs LOAD, TA = +25°C, V IN = 28V Quick Setup Guide 1. Ensure correct board connection to the supply (“+” to VIN1 and “-” to GND2) and loads prior to applying power, then turn on the power supply. 2. Verify the output voltage is 5V for VOUT1 and 3.3V for VOUT2. Frequency Control ISL85033 has an FS pin that controls the frequency of operation. Programmable frequency allows for optimization between efficiency and external component size. ISL85033EVAL2Z has the switching frequency set to 500kHz (FS is tied to VCC). SYNC Control The ISL85033 has a SI pin for external synchronization. Default board configuration has R8 = 0 to GND, which defaults to the internally selected switching frequency. Removing R8 allows the synchronization to be external between 600kHz to 4MHz. Do not leave this pin floating. Output Voltage Selection FIGURE 2. ISL85033EVAL2Z TOP SILK SCREEN ISL85033EVAL2Z board has VOUT1 set to 5V and VOUT2 set to 3.3V. The output voltage programming resistor, R3 (R10 respectively), will depend on the value chosen for the feedback resistor, R2 (R12 respectively), and the desired output voltage, VOUT, see Equation 1. The value for R2 is typically between 1k and 10k. R 3 = ( V OUT1 – V FB ) • R 2 ⁄ 0.8 (EQ. 1) R 10 = ( V OUT2 – V FB ) • R 12 ⁄ 0.8 January 3, 2011 AN1584.1 1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. Copyright Intersil Americas Inc. 2011. 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 1584 Please note that if VOUT is less than 2.5V, switching frequency and compensation must be changed for 300kHz operation due to minimum on-time limitation. Please refer to data sheet FN6676 for further information. Current Sharing Option The ISL85033EVAL2Z board has the option to be configured for current sharing operation. The following changes will allow a default output voltage of 5V. The output maximum operating current will be 6A. 1. Remove R5, R6, R9, R10, R11, R12, C11, C13. 2. Add a short (0Ω 0603 resistor) to the place holder of R16, R17. 3. Connect a wire from VOUT1 to VOUT2. 4. Place C2 = 22nF (50V/0603). Place C15 = 22nF 5. Change the value of C4 to 1nF (50V, 0603). 6. Change the value of R4 to 34k (0603). 2 AN1584.1 January 3, 2011 VCC PGOOD2 SYNCOUT SYNCIN PGOOD1 VCC ISL85033EVAL2Z Schematic R13 DNP NC1 A VOUT1 A 4 C2 OPEN BOOT1 5 C5 A A 6 0.01UF 7 29 A U1 SS2 PGND2 BOOT2 PHASE2 PHASE2 PHASE1 PHASE1 EP 7UH A A A 0.01UF R12 8.06K A A FB1 L2 1 COMP1 2 C7 10UF COMP2 A VIN2 SS1 R18 SS2 DNP C10 10UF A GND2 R17 DNP VIN2 C8 10UF FB2 VO2 C14 47UF A C9 4.7UF R16 DNP VOUT2 VOUT2=3.3V 2 7UH D2 B340B VIN1 VIN2 GND4 A VIN1 R15 C12 16 15 2 A VIN1 C15 OPEN 1 D1 B340B C3 47UF R11 0 0 BOOT2 8 9 10 11 12 13 14 2 A FB2 18 17 C16 68PF SS2 19 1 1 ISL85033IRTZ SS1 PGND1 BOOT1 C13 20 69.8K 470PF A L1 VOUT1 VOUT1=5V 21 COMP2 FB2 R10 25.5K Application Note 1584 GND1 COMP1 FB1 VCC R2 8.06K 1 COMP2 28 27 26 25 24 23 22 C4 FB1 470PF 69.8K 2 SS1 3 C11 12PF R9 VIN1 VIN1 EN1 VCC EN2 VIN2 VIN2 A 3 12PF R4 PGOOD1 FS NC SGND SYNCIN SYNCOUT PGOOD2 C6 R3 42.2K R1 0 COMP1 C1 68PF VO1 R14 DNP VOUT2 GND3 SGND A A A A A IF VOUT1=5V (4.5V-5.5V) PLS POPULATE R26 IF VOUT2=5V (4.5V-5.5V) PLS POPULATE R27 OTHERWISE PLS LEAVE R26, R27 DNP! R5 0 ONLY ONLY R7 DNP R6 0 SYNCIN SS1 DRAWN BY: SS2 R8 0 RELEASED UPDATED A PAUL ORFANU BY: BY: TIM KLEMANN DATE: 06/21/2010 DATE: DATE: 06/23/2010 TESTER ENGINEER: PAUL ORFANU TITLE: ISL85033EVA WIDE VIN DUAL STAN SCHEMATI AN1584.1 January 3, 2011 Application Note 1584 TABLE 1. BILL OF MATERIALS PART NUMBER QTY UNITS ISL85033EVAL2ZREVAPCB 1 ea GMK325BJ106KN-T 2 ea H1044-00120-50V5-T 2 ea H1044-00680-50V5-T H1045-00103-50V10-T H1045-00471-50V5-T H1045-00475-6R3V10-T 2 2 2 1 ea ea ea ea REFERENCE DESIGNATOR DESCRIPTION MANUFACTURER MANUFACTURER PART PWB-PCB, ISL85033EVAL2Z, REVA, ROHS IMAGINEERING INC ISL85033EVAL2ZREVAPCB C8, C10 CAP, SMD, 1210, 10µF, 35V, 10%, X5R, ROHS TAIYO YUDEN GMK325BJ106KN-T C6, C11 CAP, SMD, 0402, 12pF, 50V, 5%, NPO, ROHS AVX 04025C120JAT VENKEL C0402C0G500-120JNE CAP, SMD, 0402, 68pF, 50V, 5%, NPO, ROHS MURATA GRM36COG680J050AQ PANASONIC ECJ-0EC1H680J VENKEL C0402COG500-680JNE MURATA GRM39X7R103K050 AVX 06035C103KAT2A VENKEL C0603X74500-103KNE CAP, SMD, 0603, 470pF, 50V, 5%, NPO, ROHS PANASONIC ECJ-1VC1H471J VENKEL C0603COG500-471JNE CAP, SMD, 0603, 4.7µF, 6.3V, 10%, X5R, ROHS VENKEL C0603X5R6R3-475KNE TDK C1608X5R0J475K PANASONIC ECJ-1VB0J475K MURATA GRM188R60J475KE19D KEMET C0603C475K9PACTU TAIYO YUDEN JMK107BJ475KA-T C1, C16 C5, C12 C4, C13 C9 CAP, SMD, 0603, 0.01µF, 50V, 10%, X7R, ROHS H1045-DNP 0 ea C2, C15 CAP, SMD, 0603, DNPPLACE HOLDER, ROHS H1082-00106-50V10-T 1 ea C7 CAP, SMD, 1210, 10µF, 50V, 10%, X5R, ROHS TAIYO YUDEN UMK325BJ106KM-T H1082-00476-16V20-T 2 ea C3, C14 CAP, SMD, 1210, 47µF, 16V, 20%, X5R, ROHS TDK C3225X5R1C476M PANASONIC ECJ-4YB1C476M MURATA GRM32ER61C476ME15L TAIYO YUDEN EMK325BJ476MM-T KEMET C1210C476M4PACTU VENKEL C1210X5R160-476MNE SQL004 2 ea L1, L2 COIL-PWR INDUCTOR, SMD, 10mm, 7µH, 25%, 4.8A, ROHS FALCO SQL004 1514-2 8 ea VO1,VO2, GND1GND4, VIN1, VIN2 CONN-TURRET, TERMINAL POST, TH, ROHS KEYSTONE 1514-2 B340B-13-F-T 2 ea D1, D2 DIODE-SCHOTTKY, SMD, SMB, 2P, 40V, 3A, ROHS DIODES INC. B340B-13-F ISL85033IRTZ 1 ea U1 IC-3A DUAL STD REGULATOR, 28P, TQFN, 4x4, ROHS INTERSIL ISL85033IRTZ H2505-DNP 0 ea R7, R13, R14, R16R18 RESISTOR, SMD, 0603, 0.1%, MF, DNP-PLACE HOLDER 4 AN1584.1 January 3, 2011 Application Note 1584 TABLE 1. BILL OF MATERIALS (Continued) PART NUMBER H2510-00R00-1/16W-T H2510-02552-1/16W1-T H2510-04222-1/16W1-T H2510-08061-1/16W1-T H2511-00R00-1/10W-T H2511-06982-1/10W1-T QTY UNITS 2 ea 1 1 2 3 2 ea ea ea ea ea REFERENCE DESIGNATOR R1, R11 R10 R3 R2, R12 R5, R6, R8 R4, R9 MANUFACTURER MANUFACTURER PART RES, SMD, 0402, 0Ω, 1/16W, 5%, TF,ROHS VENKEL CR0402-16W-00T PANASONIC ERJ-2GE0JR00 RES, SMD, 0402, 25.5k, 1/16W, 1%, TF, ROHS VENKEL CR0402-16W-2552FT PANASONIC ERJ-2RKF2552X VISHAY/DALE CRCW040225K5FKED RES, SMD, 0402, 42.2k, 1/16W, 1%, TF, ROHS PANASONIC ERJ-2RKF4222X VENKEL CR0402-16W-4222FT RES, SMD, 0402, 8.06k, 1/16W, 1%, TF, ROHS VENKEL CR0402-16W-8061FT PANASONIC ERJ-2RKF8061X ROHM MCR01MZPF8061 YAGEO RC0402FR-078K06L VISHAY/DALE CRCW04028K06FKED VENKEL CR0603-10W-000T ROHM MCR03EZPJ000 PANASONIC ERJ-3GEY0R00V YAGEO RC0603JR-070RL VISHAY/DALE CRCW06030000Z0EA VENKEL CR0603-10W-6982FT YAGEO RC0603FR-0769K8L VISHAY/DALE CRCW060369K8FKEA KOA RK73H1JTTD6982F VENKEL CR1210-4W-000 RES, SMD, 0603, 0Ω, 1/10W, TF, ROHS RES, SMD, 0603, 69.8k, 1/10W, 1%, TF, ROHS H2514-00R00-1/4W-T 1 ea SJ-5003-BLACK 2 ea BUMPONS,0.44” W x 0.20” 3M H, DOMETOP, BLACK SJ-5003SPBL 3X5-STATIC-BAG 1 ea BAG, STATIC, 3 X 5, ZIP LOC INTERSIL COMMON STOCK D810 (212403-012) LABEL-SERIAL NUMBER 1 ea LABEL-FOR SERIAL NUMBER AND BOM REV # LABEL-SERIAL NUMBER 5 R15 DESCRIPTION RES, SMD, 1210, 0Ω, 1/4W, TF, ROHS INTERSIL AN1584.1 January 3, 2011 Application Note 1584 ISL85033EVAL2Z Board Layout FIGURE 3. TOP ASSEMBLY FIGURE 4. TOP SILK SCREEN 6 AN1584.1 January 3, 2011 Application Note 1584 ISL85033EVAL2Z Board Layout (Continued) FIGURE 5. TOP LAYER COMPONENT SIDE FIGURE 6. LAYER 2 7 AN1584.1 January 3, 2011 Application Note 1584 ISL85033EVAL2Z Board Layout (Continued) FIGURE 7. LAYER 3 FIGURE 8. BOTTOM LAYER SOLDER SIDE 8 AN1584.1 January 3, 2011 Application Note 1584 ISL85033EVAL2Z Board Layout (Continued) FIGURE 9. BOTTOM SILK SCREEN FIGURE 10. BOTTOM SILK SCREEN 9 AN1584.1 January 3, 2011 Application Note 1584 ISL85033EVAL2Z Board Layout (Continued) FIGURE 11. BOTTOM ASSEMBLY 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 10 AN1584.1 January 3, 2011