Application Note 1574 Author: Paul Orfanu ISL85033DUALEVAL1Z Wide VIN Dual Standard Buck Regulator With 3A/3A Output Current Quick Setup Guide Description The ISL85033DUALEVAL1Z kit is intended for use by individuals with requirements for Point-of-Load applications sourcing from 4.5V to 28V. The ISL85033DUALEVAL1Z evaluation board is used to demonstrate the performance of the ISL85033 wide VIN dual standard buck regulator with 3A/3A output current converter. The ISL85033 is offered in a 4mmx4mm 28 Ld TQFN package with 1mm maximum height. The complete converter occupies 6.25cm2 area. Key Features • Wide Input Voltage Range from 4.5V to 28V • Adjustable Output Voltage with Continuous Output Current up to 3A • Current Mode Control • Adjustable Switching Frequency from 300kHz to 2MHz • Independent Power-Good Detection • Selectable In-Phase or Out-of-Phase PWMs Switching Operation • Independent, Sequential, Ratiometric or Absolute Tracking Between Outputs • Internal 2ms Soft-start Time • Overcurrent and Hiccup Mode Short Circuit Protection, Thermal Overload Protection, UVLO • Boot Undervoltage Detection • Channels are Out-of-phase, Reducing Voltage Ripple and Component Size Recommended Equipment The following materials are recommended to perform testing: • 0V to 30V Power Supply with at least 7A source current capability or 5V battery • Electronic Loads capable of sinking current up to 7A • Digital Multimeters (DMMs) • 100MHz quad-trace oscilloscope • Signal generator November 29, 2010 AN1574.2 1 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 GND2. 3. Verify that the position is ON for S1 and S2. 4. Turn on the power supply. 5. Verify the output voltage is 5V for VOUT1 and 3.3V for VOUT2. Evaluating the Other Output Voltage The ISL85033DUALEVAL1Z kit outputs are preset to 5V for VOUT1 and 3.3V for VOUT2; however, output voltages can be adjusted from 0.8V to 5V. The output voltage programming resistor, R3 (or R14 in Channel 2), will depend on the desired output voltage of the regulator and the value for the feedback resistor R2 (R16 respectively), as shown in Equation 1. R3 = ( V OUT1 – V FB ) • R2 ⁄ V FB (EQ. 1) R14 = ( V OUT2 – V FB ) • R16 ⁄ V FB If the output voltage desired is 0.8V, then R3 (R14 respectively) is shorted. The value for R2 (R16 respectively) is typically between 1k and 10k. Please note that if VOUT is less than 2.5V, the switching frequency and compensation must be changed for 300kHz operation due to minimum on-time limitation. Please refer to the data sheet for further information (FN6676). Frequency Control ISL85033 has an FS pin that controls the frequency of operation. Programmable frequency allows for optimization between efficiency and external component size. Default switching frequency is 500kHz when FS is tied to VCC (R9 = 0). By removing R9 and connecting R10 to ground, the switching frequency could be changed from 300kHz (R10 = 383k) to 2MHz (R10 = 40.2k). Please refer to the data sheet (FN6676) for calculating the value of R10. Do not leave this pin floating. CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. Copyright Intersil Americas Inc. 2010. 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 1574 Disabling/enabling Function TABLE 2. The ISL85033 evaluation board contains S1, S2 switches to enable or disable each of the channels, thus allowing low quiescent current state. Table 1 details this function. EN1 EN2 VOUT1 VOUT2 High Floating First After VOUT1 > 90% TABLE 1. SWITCH SETTINGS Floating High After VOUT2 > 90% First High High Same time as VOUT2 Same time as VOUT1 Floating Floating S1 S2 ON/OFF CONTROL ON OFF Enable VOUT1; Disable VOUT2 OFF ON Disable VOUT1; Enable VOUT2 ON ON Enable VOUT1; Enable VOUT2 OFF OFF Disable VOUT1; Disable VOUT2 If EN1 or EN2 are floating, then the outputs will start in the sequencing described in the data sheet section on output sequencing and also summarized in Table 2. 2 NOTE Not Allowed SYNC Control The ISL85033 evaluation board has an SI pin that allows external synchronization frequency to be applied. Default board configuration has R18 = 0 to GND, which defaults to the internal selected switching frequency. Removing R18 allows the synchronization to be external between 600kHz to 4MHz. Do not leave this pin floating. AN1574.2 November 29, 2010 ISL85033DUALEVAL1Z Schematic SS1 3 A 0.01UF 7 L1 A A A R20 DNP PGOOD1 C7 A PGOOD2 SGND EN1 PGOOD2 A COMP2 A SYNCIN A SS2 C9 A C8 10UF A VOUT2 VOUT2=3.3V C12 47UF DNP A BOOT2 D3 DNP GND3 D4 VCC EN2 BOOT1 DNP A BOOT2 D5 D6 DNP DNP EXT_5V A S2 A SS1 SS2 0 FS R10 DNP A R26 R17 DNP R9 0 0 R6 EN2 ON OPEN OFF R8 SYNCIN R18 0 ON OPEN S1 OFF 100K R4 AN1574.2 November 29, 2010 EN1 100K VCC R7 A DNP VOUT1 VO2 VIN2 A BOOT1 A VIN1 R22 JLX2 7UH C17 VIN2 R21 DNP VOUT2 0 VIN2 GND4 A L2 D2 VOUT1 R16 8.06K A B340B A A FB2 C11 OPEN 15 0.01UF VIN1 C6 10UF R15 0 470PF BOOT2 16 A C18 10UF R19 DNP A PHASE2 D1 VCC GND2 PHASE1 EP C16 68PF C10 18 17 JVO2 R14 25.5K SS2 19 BOOT2 PHASE2 B340B 47UF A ISL85033IRTZ PHASE1 A 7UH C14 C2 DNP VIN1 29 A JLX1 VOUT1 VOUT1=5V BOOT1 6 12PF R11 20 69.8K PGND2 EN1 VCC EN2 A A PGND1 C15 21 SS2 U1 DNP VOUT2 VIN1 VIN1 EN1 VCC EN2 VIN2 VIN2 GND1 R13 R27 DNP VOUT2 FB1 R23 COMP1 R24 SS1 R25 DNP DNP DNP FB2 COMP2 SS2 Application Note 1574 C5 DNP FB2 SS1 BOOT1 5 R12 COMP2 FB1 4 C3 OPEN VCC PG2 8 9 10 11 12 13 14 SS1 R2 8.06K COMP1 470PF 69.8K 2 A FB1 1 4.7UF C4 SO PGOOD1 FS NC SGND SYNCIN SYNCOUT PGOOD2 12PF R5 A 3 R1 0 A C13 R3 42.2K COMP1 C1 68PF JVO1 A SI 28 27 26 25 24 23 22 VOUT1 VO1 FS GND PGOOD1 FS PG1 Application Note 1574 TABLE 3. BILL OF MATERIALS PART NUMBER REFERENCE DESIGNATOR QTY UNITS DESCRIPTION MANUFACTURER MANUFACTURER PART # ISL85033EVAL1ZREVBPCB 1 ea SEE LABEL-RENAME BOARD PWB-PCB, ISL85033EVAL1Z, REVB, ROHS TBD ISL85033EVAL1ZREVBPCB EEE-FK1V101P-T 0 ea DNP (C2, C12) CAP, SMD, 8X10.2, 100µF, 35V, 20%, AL.EL., ROHS PANASONIC EEE-FK1V101P GMK325BJ106KN-T 2 ea C6, C8 CAP, SMD, 1210, 10µF, 35V, 10%, X5R, ROHS TAIYO YUDEN GMK325BJ106KN-T H1044-00120-50V5-T 2 ea C13, C15 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 H1044-00680-50V5-T H1045-00103-50V10-T H1045-00471-50V5-T H1045-00475-6R3V10-T 2 ea 2 ea 2 ea 1 ea C1, C16 C5, C9 C4, C10 C7 CAP, SMD, 0603, 0.01µF, 50V, 10%, X7R, ROHS H1045-DNP 0 ea C3, C11 CAP, SMD, 0603, DNP-PLACE HOLDER, ROHS H1082-00106-50V10-T 1 ea C18 CAP, SMD, 1210, 10µF, 50V, 10%, X5R, ROHS TAIYO YUDEN UMK325BJ106KM-T H1082-00476-16V20-T 2 ea C14, C17 CAP, SMD, 1210, 47µF, 16V, 20%, X5R, ROHS TDK C3225X5R1C476M PANASONIC ECJ-4YB1C476M MURATA GRM32ER61C476ME15L TAIYO YUDEN EMK325BJ476MM-T KEMET C1210C476M4PACTU VENKEL C1210X5R160-476MNE FALCO SQL004 TEKTRONIX 131-4353-00 SQL004 2 ea L1, L2 131-4353-00 4 ea JLX1, JLX2, JVO1, JVO2 CONN-SCOPE PROBE TEST PT, COMPACT, PCB MNT, ROHS 4 COIL-PWR INDUCTOR, SMD, 10mm, 7µH, 25%, 4.8A, ROHS AN1574.2 November 29, 2010 Application Note 1574 TABLE 3. BILL OF MATERIALS (Continued) PART NUMBER REFERENCE DESIGNATOR QTY UNITS DESCRIPTION MANUFACTURER MANUFACTURER PART # KEYSTONE 1514-2 a) FS, SI, SO, EN1, EN2, CONN-MINI TEST GND, PG1, PG2 POINT, VERTICAL, WHITE, ROHS KEYSTONE 5002 ea b) SS1, SS2, EXT_5V CONN-MINI TEST POINT, VERTICAL, WHITE, ROHS KEYSTONE 5002 2 ea D1, D2 DIODE-SCHOTTKY, DIODES INC. SMD, SMB, 2P, 40V, 3A, ROHS ISL85033IRTZ 1 ea U1 IC-3A DUAL STD REGULATOR, 28P, TQFN, 4x4, ROHS H2505-DNP 0 ea R10, R17, R19, R20, R23-R27 RESISTOR, SMD, 0603, 0.1%, MF, DNP-PLACE HOLDER H2510-00R00-1/16W-T 2 ea R1, R15 VENKEL RES, SMD, 0402, 0Ω, 1/16W, 5%, TF, PANASONIC ROHS 1514-2 8 ea VO1, VO2, GND1GND4, VIN1, VIN2 5002 11 ea 5002 0 B340B-13-F-T H2510-02552-1/16W1-T H2510-04222-1/16W1-T H2510-08061-1/16W1-T H2511-00R00-1/10W-T H2511-01004-1/10W1-T 1 ea 1 ea 2 ea 4 ea 2 ea 5 R14 R3 R2, R16 R7-R9, R18 R4, R6 CONN-TURRET, TERMINAL POST, TH, ROHS INTERSIL B340B-13-F ISL85033IRTZ CR0402-16W-00T ERJ-2GE0JR00 VENKEL CR0402-16W-2552FT PANASONIC ERJ-2RKF2552X VISHAY/DALE CRCW040225K5FKED STACKPOLE RMC 1/16S 25.5K 1% R 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 RES,SMD, 0402, 25.5k, 1/16W, 1%, TF, ROHS RES, SMD, 0603, 0Ω, 1/10W, TF, ROHS PANASONIC RES, SMD, 0603, 1M, 1/10W, 1%, TF, VENKEL ROHS ERJ-3EKF1004V CR0603-10W-1004FT YAGEO RC0603FR-071ML ROHM MCR03EZPFX1004 KOA RK73H1JTTD1004F VISHAY/DALE CRCW06031M00FKEA AN1574.2 November 29, 2010 Application Note 1574 TABLE 3. BILL OF MATERIALS (Continued) PART NUMBER H2511-06982-1/10W1-T REFERENCE DESIGNATOR QTY UNITS 2 ea R5, R11 DESCRIPTION RES, SMD, 0603, 69.8k, 1/10W, 1%, TF, ROHS MANUFACTURER MANUFACTURER PART # VENKEL CR0603-10W-6982FT YAGEO RC0603FR-0769K8L VISHAY/DALE CRCW060369K8FKEA KOA RK73H1JTTD6982F H2511-DNP 0 ea R12, R13 RES, SMD, 0603, DNP-PLACE HOLDER, ROHS H2514-00R00-1/4W-T 1 ea R22 RES, SMD, 1210, VENKEL 0Ω, 1/4W, TF, ROHS H2514-DNP 0 ea R21 RES, SMD, 1210, DNP, DNP, DNP, TF, ROHS GT13MCBE 2 ea S1, S2 SWITCH-TOGGLE, THRU-HOLE, 5PIN, SPDT, 3POS, ONOFF-ON, ROHS C&K COMPONENTS GT13MCBE SJ-5003-BLACK 4 ea Bottom four corners BUMPONS, 0.44’ W x 0.20’ H, DOMETOP, BLACK 3M SJ-5003SPBL 5X8-STATIC-BAG 1 ea Place assy in bag BAG, STATIC, 5X8, ZIPLOC, ROHS INTERSIL 212403-013 DNP 0 ea D3-D6 DO NOT POPULATE OR PURCHASE LABEL-RENAME BOARD 1 ea RENAME PCB TO: ISL85033DUALEVAL1Z LABEL, TO RENAME INTERSIL BOARD LABEL-SERIAL NUMBER 1 ea 6 CR1210-4W-000 LABEL-RENAME BOARD LABEL, FOR SERIAL NUMBER AND BOM REV # AN1574.2 November 29, 2010 Application Note 1574 ISL85033DUALEVAL1Z Board Layout FIGURE 1. TOP LAYER COMPONENTS FIGURE 2. TOP LAYER ETCH 7 AN1574.2 November 29, 2010 Application Note 1574 ISL85033DUALEVAL1Z Board Layout (Continued) FIGURE 3. SECOND LAYER ETCH FIGURE 4. THIRD LAYER ETCH 8 AN1574.2 November 29, 2010 Application Note 1574 ISL85033DUALEVAL1Z Board Layout (Continued) FIGURE 5. BOTTOM LAYER ETCH FIGURE 6. BOTTOM LAYER COMPONENTS 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 9 AN1574.2 November 29, 2010