Application Note 1927 ISL78236DUALEVAL1Z Dual Output Evaluation Board User Guide Description Quick Setup Guide The ISL78236DUALEVAL1Z kit is intended for use by individuals with requirements for Point-of-Load (POL) applications sourcing from 2.85V to 6V. The ISL78236DUALEVAL1Z evaluation board is used to demonstrate the performance of the ISL78236 low quiescent current mode converter. The evaluation board is configured to deliver up to 3A output current on each of the two output channels. The ISL78236 can be configured in a current share mode for a single 6A output current. For this application, reference ISL78236CRSHEVAL1Z AN1928. The ISL78236 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 evaluation board is correctly connected to the supply and loads prior to applying any power. 2. Connect the bias supply to VIN: The positive terminal to VIN1 and the negative return to PGND1. 3. Verify that switch position is on PWM for S1. Verify that switch position is ON for S2 and S3. 4. Turn on the power supply. 5. Verify the output voltage is 1.8V for both channels. Evaluating Other Output Voltages • 180° out-of-phase channel switching The ISL78236DUALEVAL1Z kit outputs are preset to 1.8V for VOUT1 and 1.8V for VOUT2; however, output voltages can be adjusted from 1.2V to 3.3V. The output voltage programming resistor, RF12 (or RF22 in Channel 2), will depend on the desired output voltage of the regulator. The value for the feedback resistor (RF12 and RF22) is typically between 50kΩ and 750kΩ as shown in Equations 1 and 2. • 2% output accuracy over-temperature/load/line Setting RF11 and RF21 = 100k, then RF12 and RF22 will be: Key Features • Dual 3A high efficiency synchronous buck regulator with up to 95% efficiency • Internal digital soft-start - 1.5ms V OUT1 RF12 = RF11 ---------------- – 1 0.8 (EQ. 1) • Internal current mode compensation V OUT2 RF22 = RF21 ---------------- – 1 0.8 (EQ. 2) • Peak current limiting, hiccup mode short circuit protection and over-temperature protection SYNC Mode Control • Soft-stop output discharge during disable • Typical 8µA shutdown current • 100% maximum duty cycle for lowest dropout • Negative current detection and protection Recommended Equipment The following equipment is recommended to perform evaluation of this board: • 5V or higher power supply with at least 6A source current capability or 5V battery • Electronic loads capable of sinking current up to 3A The ISL78236 has a SYNC pin, which connects to logic high or input voltage VIN for internal 2.5MHz switching frequency. Connect the test point by the switch S1 to an external function generator for external synchronization on the negative edge trigger. A 100kΩ pull-up resistor to VIN normally pulls the SYNC pin high. Each channel’s switching frequency will be 1/2 of the synchronization frequency at 180° out-of-phase. Synchronization frequency range is 6MHz to 8MHz. Do not leave this pin floating. Do not tie this pin low (or to GND). TABLE 1. SWITCH SETTINGS • Digital Multimeters (DMMs) • 100MHz quad-trace oscilloscope • 10MHz signal generator SWITCH POSITION S1 PFM DO NOT LEAVE IN THIS POSITION PWM 2.5MHz switching frequency if floating. External synchronization switching 6MHz to 8MHz range with generator. Ordering Information PART NUMBER ISL78236DUALEVAL1Z DESCRIPTION Dual Output 3A/3A Synchronous Buck Evaluation Board S2 S3 June 17, 2014 AN1927.0 1 MODE ON Enable VOUT1 OFF Disable VOUT1 ON Enable VOUT2 OFF Disable VOUT2 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. Copyright Intersil Americas LLC. 2014. 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. LX2_S LX1_S LX2 A VIN2 VIN1 VIN2 0 CIN2 22UF SYNC R_PH SYNC 0 S1 PWM PFM C_PH OPEN RF22 124K C5 C1 OPEN R3 OPEN A C2 OPEN A 12PF R7 RF21 100K A A A A R4 100K SGND SGND ON/EX OFF S3 ON/EX OFF EN2 EN1 A EN2 PG2 EN2 A PG2 A COMP NC FB1 SGND PG1 SYNC C11 22UF VOUT1_S A A RF12 124K C10 12PF PGND1 A A 2N7002 Q1 A PG1 PG1 0 R12 2K C8 150PF D1 R13 VIN_PG R11 52.3K R14 OPEN D2 2N7002 Q2 A VOUT1 VOUT1_S C6 C7 OPEN OPEN PGND RF11 100K R8 2K R10 OPEN C9 22UF A VIN_PG A R6 100K EN1 A A COMP A EN1 VOUT1 VOUT1 SYNC CD1 OPEN COMP VDD S2 PG1 FB1 VDD EN1 A CDC OPEN OPEN PGND PGND2 A R9 VOUT2_S SS SYNC C3 C4 22UF 22UF VOUT2_S EN1 COMP 0 VDD FB2 EP SS VOUT2 OPEN VDD SS VDD ISL8036AIRZ PG2 ISL78236AIRZ R_OUT L1 VIN1 EN2 A VIN1 Application Note 1927 SS VOUT2 LX1 LX1 VIN1 U1 VIN2 EN2 PG2 FB2 FB FB VOUT2 VOUT2 CD2 R5 L2 OPEN R2 LX2 VIN2 VIN1 0 R1 100K LX2 PGND PGND11 LX2 PGND2 PGND2 PGND1 PGND1 LX1 2 A VIN1 CIN1 22UF A A PGND VDD VIN1 VIN1 PGND22 VDD A VIN2 FB1 R_IN VIN2 LX1 0 Submit Document Feedback ISL78236DUALEVAL1Z Schematic AN1927.0 June 17, 2014 QTY UNITS ISL8033_36EVAL1ZREVAPCB 1 ea. a) PUT “X” IN ISL8036 BOX ON PCB PWB-PCB, ISL8033_36EVAL1Z, REVA, ROHS IMAGINEERING INC. ISL8033_36EVAL1ZREVAPCB ISL8033_36EVAL1ZREVAPCB 0 ea. b) SEE LABEL-RENAME BOARD PWB-PCB, ISL8033_36EVAL1Z, REVA, ROHS IMAGINEERING INC. ISL8033_36EVAL1ZREVAPCB C2012X5R0J226M-T 6 ea. C3, C4, C9, C11, CIN1, CIN2 CAP, SMD, 0805, 22µF, 6.3V, 20%, X5R, ROHS TDK C2012X5R0J226M 3 H1045-00120-50V5-T 2 ea. C5, C10 CAP, SMD, 0603, 12pF, 50V, 5%, COG, AVX ROHS 06035A120JAT2A H1045-00151-50V5-T 1 C8 CAP, SMD, 0603, 150pF, 50V, 5%, NPO, ROHS ECJ-1VC1H151J H1045-DNP 0 ea. C1, C2, C8, CD1, CD2, CDC, C_PH CAP, SMD, 0603, DNP-PLACE HOLDER, ROHS H1046-DNP 0 ea. C6, C7 CAP, SMD, 0805, DNP-PLACE HOLDER, ROHS FDV0630-R60M 2 ea. L1, L2 COIL-PWR INDUCTOR, SMD, 7.4X6.7, TOKO 0.6µH, 20%, ROHS 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. a) PGND1, PGND2, PGND11, PGND22, VIN1, VIN2 CONN-TURRET, TERMINAL POST, TH, ROHS 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, VERTICAL, RED, KEYSTONE ROHS 5000 5000 0 ea. b) SYNC located left of C_PH CONN-MINI TEST PT, VERTICAL, RED, KEYSTONE ROHS 5000 5001 1 ea. SGND CONN-MINI TEST PT, VERTICAL, BLK, ROHS KEYSTONE 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, LITEON/VISHAY 100mW, 40mA, 10mcd, ROHS LTST-C170CKT ISL78236IRZ 1 ea. U1 IC-DUAL 3A BUCK REGULATOR, 2.5MHz, 24P, QFN, 4X4, ROHS INTERSIL ISL78236IRZ 2N7002-7-F-T 2 ea. Q1, Q2 TRANSISTOR, N-CHANNEL, 3 LD, SOT-23, 60V, 115mA, ROHS DIODES, INC. 2N7002-7-F H2509-DNP 1 ea. R9 RES, SMD, 0201, 0Ω, 1/20W, 0%, TF PANASONIC H2509-00R00-1/20W-T H2511-00R00-1/10W-T 4 ea. R2, R5, R13, R_PH RES, SMD, 0603, 0Ω, 1/10W, TF, ROHS CR0603-10W-000T PART NUMBER REFERENCE DESIGNATOR DESCRIPTION MANUFACTURER PART MANUFACTURER PANASONIC VENKEL Application Note 1927 AN1927.0 June 17, 2014 Submit Document Feedback Bill of Materials Submit Document Feedback Bill of Materials (Continued) QTY UNITS H2511-01003-1/10W1-T 5 ea. R1, R4, R6, RF11, RF21 RES, SMD, 0603, 100k, 1/10W, 1%, TF, ROHS H2511-01243-1/10W1-T 2 ea. RF12, RF22 RES, SMD, 0603, 124k, 1/10W, 1%, YAGEO TF, ROHS 9C06031A1243FKHFT H2511-02001-1/10W1-T 2 ea. R8, R12 RES, SMD, 0603, 2k, 1/10W, 1%, TF, KOA ROHS RK73H1JTTD2001F 4 H2511-05232-1/10W1-T 1 ea. R11 RES, SMD, 0603, 52.3k, 1/10W, 1%, VENKEL TF, ROHS CR0603-10W-5232FT H2511-DNP 0 ea. R3, R7, R10, R14 RES, SMD, 0603, DNP-PLACE HOLDER, ROHS PART NUMBER REFERENCE DESIGNATOR DESCRIPTION MANUFACTURER MANUFACTURER PART 1 ea. R_IN RES, SMD, 1210, 0Ω, 1/4W, TF, ROHS VENKEL H2514-DNP 0 ea. R_OUT RES, SMD, 1210, DNP, DNP, DNP, TF, ROHS GT11MSCBE-T 3 ea. S1-S3 SWITCH-TOGGLE, SMD, 6 PIN, SPDT, 2POS, ON-ON, ROHS ITT INDUSTRIES/C&K DIVISION GT11MSCBE SJ-5003-BLACK 4 ea. Bottom four corners BUMPONS, 0.44”Wx0.20”H, DOMETOP, BLACK 3M SJ-5003SPBL 5X8-STATIC-BAG 1 ea. Place assy in bag BAG, STATIC, 5X8, ZIP LOC INTERSIL 212403-013 LABEL-RENAME BOARD 1 ea. RENAME PCB TO: ISL78236DUALEVAL1Z LABEL, TO RENAME BOARD INTERSIL LABEL-RENAME BOARD LABEL-SERIAL NUMBER 1 ea. LABEL, FOR SERIAL NUMBER AND BOM REV # CR1210-4W-000 Application Note 1927 H2514-00R00-1/4W-T AN1927.0 June 17, 2014 Application Note 1927 ISL78236DUALEVAL1Z Board Layout FIGURE 1. TOP COMPONENTS FIGURE 2. TOP LAYER ETCH FIGURE 3. 2ND LAYER ETCH FIGURE 4. 3RD LAYER ETCH Submit Document Feedback 5 AN1927.0 June 17, 2014 Application Note 1927 ISL78236DUALEVAL1Z Board Layout FIGURE 5. BOTTOM LAYER ETCH (Continued) 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 Submit Document Feedback 6 AN1927.0 June 17, 2014