Application Note 1528 ISL8120EVAL3Z Evaluation Board Setup Procedure Description Recommended Equipment The ISL8120 integrates two voltage mode synchronous buck PWM controllers. It can be used either for dual independent outputs or a 2-phase single output regulator. • 0V to 22V power supply with at least 20A source current capability, battery, or notebook AC adapter. The ISL8120EVAL3Z evaluation board is for performance demo of the dual independent outputs and DDR applications. • Digital multimeters (DMMs). The ISL8120EVAL4Z evaluation board is used for performance demo of 2/n-phase single-output applications. Refer to application note AN1607 “ISL8120EVAL4Z Evaluation Board Setup Procedure” for details of the ISL8120EVAL4Z board. • Two electronic loads capable of sinking current up to 30A • 100MHz quad-trace oscilloscope. References • ISL8120 Datasheet • AN1607, “ISL8120EVAL4Z Evaluation Board Setup Procedure” Preset Specifications Ordering Information VIN (V) FREQUENCY (kHz) VOUT1 VOUT2 12 500 1.2V/25A 1.2V/25A PART NUMBER ISL8120EVAL3Z DESCRIPTION ISL8120 Evaluation Board for Performance Demo FIGURE 1. ISL8120EVAL3Z EVALUATION BOARD June 25, 2015 AN1528.1 1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 1-888-468-3774 | Copyright Intersil Americas LLC 2010, 2015. All Rights Reserved 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 1528 Circuits Description J1 and J2 are the input power terminals. Two input electrolytic capacitors are used to handle the input current ripples. Two upper and two lower Renesas “speed” series LFPAK MOSFETs are used for each channel. Q1 and Q2 are footprint options for low current applications where a SO8 package integrating dual MOSFET can be used. 320nH PULSE surface mount inductors are used for each channel. Under the 500kHz setup, the inductor current peak-to-peak ripple is 7.5A at 12V input. Two SANYO POSCAP 2R5TPF470M7L (7mΩ) are used as output E-caps for each channel. Also, through-hole electrolytic capacitor footprints C123 ~ C126 are available for the user to evaluate different output capacitors. J7, J8, J9 and J10 are output lugs for load connections. TP19, TP26, TP28 and TP31 are remote sense posts. These pins can be used to monitor and evaluate the system voltage regulations. If the user wants to use these test posts for remote sense, the R109, R120, R155 and R161 need to be changed to higher values, such as 10Ω. Also, the related voltage sense divider needs to be increased to a higher resistance, such as 1k. Q26, Q27, R126, R156, R122, R131, R151, R153 are circuit footprint options to add an on-board transient load to the regulator. Use a signal generator to apply a clock signal at TP22 (TP30) to generate step-up and step-down transient load. Make sure that the duty cycle of the clock is small enough to avoid burning load resistors R126 and R156. JP11 or JP12 are the jumpers used to disable the channels independently. TP27 is a post that can be used to inject a clock signal for the controller to be synchronized with. JP7 and JP8 are jumpers for rDS(ON) sensing configuring. Also, these jumpers can be used to monitor the DCR sensing capacitor voltage. R94, C74, R163 and C108 are optional footprints for snubbers, which are used to filter the ringing at phase nodes. R99, R100, R125, R130, R132, LED4 and Q32 are useless footprints. R121 and C86 are small added filters for the VIN pin. R145 is used to isolate the noise at PVCC caused by driving. In 3.3V applications, R121 and R145, it is recommended to short to 0 to prevent VCC from going below POR under low input voltage. Also, it is recommended to add a 2k resistor from LGATE to GND to discharge the low gate at the state of LGATE OFF. Evaluating the Other Output Voltage The ISL8120EVAL3Z kit outputs are preset to 1.2V/25A, VOUT1 can also be adjusted between 0.6V to 3V by changing the value of R119 and R116 for VOUT1 as given by Equation 1. The same rule applies for VOUT2. R 116 R 119 = ------------------------------------------------ V OUT V REF – 1 where VREF = 0.6V 1. Ensure that the circuit is correctly connected to the supply and loads prior to applying any power. 2. Adjust the input supply to be 12V. Turn on the input power supply. 2 (EQ. 1) rDS(ON) Sense Configuration If the desired output voltage is higher than 3V, the current sense has to be configured as rDS(ON) sensing because of the common mode voltage limitation of the current sense differential amplifier. The default setup of ISL8120EVAL3Z is DCR sensing. The following steps show how to change to rDS(ON) sensing for Channel 2: 1. Remove R5 and R6 to be open. 2. Change R4 and R8 to be 0Ω. 3. Short jumper JP1. Programming the Input Voltage UVLO and its Hysteresis By programming the voltage divider at the EN/FF pin connected to the input rail, the input UVLO and its hysteresis can be programmed. The ISL8120EVAL3Z has R129 (R136) 13.7k and R135 (R141) 4.42k; the IC will be disabled when input voltage drops below 3.38V and will restart until VIN recovers to be above 4.42V. For 12V applications, it is suggested to have R129 (R136) 33k and R135 (R141) 5.1k, of which the IC is disabled when the input voltage drops below 6V and will restart until VIN recovers to be above 7V. Refer to equations on page 22 of the ISL8120 datasheet to program the UVLO falling threshold and hysteresis. The equations are restated in Equations 2 and 3, where RUP and RDOWN are the upper and lower resistors of the voltage divider at EN/FF pin. VHYS is the desired UVLO hysteresis and VFTH is the desired UVLO falling threshold. V HYS R UP = --------------I HYS where IHYS = 30µA R UP V ENREF R DOWN = -------------------------------------------- where RENREF = 0.8V V FTH – V ENREF Quick Start Submit Document Feedback 3. Verify that the two output voltages are correct. If the PGOOD is set high, the LED3 will be green. If the PGOOD is set low, the LED3 will be red. TP24 is the test post to monitor PGOOD. (EQ. 2) (EQ. 3) Note the ISL8120 EN/FF pin is a triple function pin and the voltages applied to the EN/FF pins are also fed to adjust the amplitude of each channel’s individual sawtooth. AN1528.1 June 25, 2015 Application Note 1528 DDR Application The ISL8120 can be used as a DDR controller. The Typical Application II schematic in the ISL8120 datasheet shows its configuration. Channel 1 is used for VDDQ. VDDQ output is fed to the REFIN pin of Channel 2, thus Channel 2 can track VDDQ at start-up and supplies as VTT. Please note the configuration of EN/FF pins for start-up timing. The VDDQ channel (Channel 1) start-up should be delayed to VTT (Channel 2) by adding more filtering at EN/FF1 than EN/FF2. This is to start up the internal SS ramp of Channel 2 and make it invalid because EN/FF2 is still 0 coming from VDDQ (Channel 1). Figure 2 shows the reference configurations and parameters of the EN/FF pins. RA is a resistor externally added as a filter resistor for EN/FF1. With the configuration of Figure 2, VDDQ is 1.8V and VTT is 0.9V. The gain of the resistor divider from VDDQ (Channel 1) to REFIN pin should have the same value with the resistor divider of VTT (Channel 2). RB is an externally added resistor for the upper resistor of the divider from VDDQ output to REFIN. FIGURE 2. DDR CONFIGURATION Submit Document Feedback 3 AN1528.1 June 25, 2015 R94 2.2_DNP 1 VOUT2 2 R95 6.49k VCC R96 0 R98 1K JP7 RED DNP C79 DNP C80 DNP C123 C124 6SEPC680M 6SEPC680M 1 J7 GND(VOUT2-) C115 10uF R103 249 1V2@25A OC=32.5A GREEN 2 1 C78 DNP 680uF, 7mOhm R102 0 J8 VOUT2 LED3 Q2A 2 4.7uF_25V_X5R C77 3 1 5 C76 0.1uF Q24 RJK0301DPB 34 Q22 RJK0305DPB Q23 RJK0301DPB 1 2 3 4 3 5 4 3 2 1 5 TP20 VOUT2 1 R97 1K Q2B 4 C75 C74 2.2nF_DNP L6 320nH 1 2 3 4 6 5 Q21 RJK0305DPB 4 5 3 2 1 8 7 Submit Document Feedback ISL8120EVAL3Z Schematic Q25 2N7002LT1 1 2 DNP C81 19 PHASE2 (O) LGATE2 20 LGATE2 (O) PVCC 21 C102 1500uF PHASE1 23 9 COMP2 (I/O) 10 11 13 12 14 16 15 VIN (I) FB2 (I/O) CLKOUT/REFIN (I/O) 7 R123 10K VCC R124 DNP C103 DNP R128 DNP VMON1 TP25 CLKOUT EN/FF2 (I/O) 6 FSYNC (I/O) 5 ISHARE (O) 3 ISET (O) 2 2. Pin7 connected to VMON1 through a voltage divider R128 and R124 will set the controller in DDR mode(Vout1-VDDQ, Vout2-VTT). R133 76.8k R135 4.42k JP12 C94 10nF R136 13.7k R141 4.42k C93 C96 1nF C98 680pF FB1 (I/O) R140 10k R129(R136)=13.7k, R135(R141)=4.42k: UVLO_RISE=4V; UVLO_FALL= 3.38V C97 1nF VCC R143 10k R142 4.02k R100 DNP R132 DNP C99 8.2nF R99 DNP 32 VMON1 (I/O) 31 VSEN1- (I) 30 VSEN1+ (I) 29 ISEN1A (I) ISEN1B (I) 28 27 VCC (I) R129(R136)=33k, R135(R141)=5.1k: UVLO_RISE=7V; UVLO_FALL= 6V R129(R136)=8.25k, R135(R141)=3.09k: UVLO_RISE=3.2V; UVLO_FALL= 2.94V 1 COMP1 (I/O) BOOT1 (I/O) R145 5.1 UGATE1 (O) 26 10uF_25V_X5R UGATE1 24 C95 10uF_16V PHASE1 (O) VIN R129 13.7k C88 10nF JP11 TP27 FSYNC 4ENABLE1 EN/FF1 (I/O) LGATE1 (O) 1. Pin7 pulled to be in voltage range between 29%Vcc and Vcc will set the controller to be in dual independant o/ps mode. And the phase shift between the 2 phase can be programmed by the voltage on this pin. ENABLE2 SYNC ISL8120IRZ PVCC (I/O) PGND (PAD) C92 22 25 C91 LGATE1 8 Enlarge the pad slightly so that a probe tip can be placed close to the IC 33 C90 C128 1500uF PGOOD (O) 3 PHASE2 VMON2 (I/O) UGATE2 (O) VSEN2- (I) 18 ISEN2B (I) UGATE2 VSEN2+ (I) BOOT2 (I/O) ISEN2A (I) 17 TP24 PGOOD3 TP26 VSEN_REM2+ 1 VIN BOOT2 VSEN_REM2+ R120 0 LED4 DNP VMON1 R152 0 VMON1 R125 DNP VCC TP28 VSEN_REM1- R154 100 C106 0.1uF R158 6.49k TP31 VSEN_REM1+ VOUT1 R161 0 TP29 TRAN1 1 Q27 DNP TP30 External Step Signal_1 C108 2.2nF_DNP 1 C110 C111 6 5 1 DNP DNP C125 C114 DNP TP23 TRAN2 TP22 External Step Signal_2 R122 DNP DNP J10 VOUT1 C126 C113 DNP Q26 DNP R151 VOUT1 R163 2.2_DNP 5 R159 100 1 2 3 4 L7 320nH R160 0 1 2 3 4 8 7 VOUT2 VSEN_REM1+ C107 0.1uF Q1A DNP 2 34 VSEN_REM1- JP8 2 C109 4.7uF_25V_X5R Q32 DNP Circuits DNP and No Use R157 249 5 5 5 Q30 RJK0305DPB 4 5 3 2 Q31 1 RJK0305DPB R149 RDSON1_DNP R130 DNP 1 R155 0 C104 2.2u Q29 RJK0301DPB 4 3 2 1 5 VCC 4 3 2 1 4 3 2 1 Q28 RJK0301DPB C101 15nF R147 1k 2 R146 45.3 BOOT1 C100 0.22u GREEN 2 RED TP32 VOUT1 C112 10uF R156 DNP R153 DNP R126 DNP R131 DNP Q1B 6SEPC680M 6SEPC680M 1 J9 GND(VOUT1-) 3 4 Optional dual MOSFET(SO8) footprint for low load current applications. 680uF, 7mOhm AN1528.1 June 25, 2015 FIGURE 3. ISL8120EVAL3Z SCHEMATIC 1V2@25A OC=32.5A Footprints for on-board transient load Application Note 1528 C87 0.22u C116 0.1uF R119 100 U3 TP3 VIN R116 100 C85 8.2nF VIN1 C86 1.5uF_25V_X5R R121 2 J2 VIN C82 680pF TP21 VIN1 TP1 GND J1 GND TP19 VSEN_REM2VSEN_REM2- R118 45.3 15nF R109 0 R111 4.02k R115 1k 4 R107 RDSON2_DNP Dual MOSFET(SO8) footprint for low load current applications. Application Note 1528 ISL8120EVAL3Z Bill of Materials REFERENCE DESCRIPTION PART NUMBER QTY C123-C126 DNP 0 C96, C97 GRM188R71H102KA 2 MURATA CAP, SMD, 0603, 1000pF, 50V, 10%, X7R, ROHS C88, C94 06032R103K8B20 2 PHILLIPS CAP, SMD, 0603, 0.01µF, 25V, 10%, X7R, ROHS C76, C106, C107, C116 GRM39X7R104K025AD 4 MURATA CAP, SMD, 0603, 0.1µF, 25V, 10%, X7R, ROHS C81, C101 ECJ-1VB1H153K 2 PANASONIC CAP, SMD, 0603, 0.015µF, 50V, 10%, X7R, ROHS C87, C100 C1608X7R1E224K 2 TDK C82, C98 GMC10CG681J50NT 2 CAL-CHIP CAP, SMD, 0603, 680pF, 50V, 5%, NPO, ROHS C85, C99 ECJ-1VB1H822K 2 PANASONIC CAP, SMD, 0603, 8200pF, 50V, 10%, X7R, ROHS C74, C103, C108 DNP 0 C95 C0805X5R160-106KNE 1 VENKEL CAP, SMD, 0805, 10µF, 16V, 10%, X5R, ROHS C86 GRM21BF51E155ZA01L 1 MURATA CAP, SMD, 0805, 1.5µF, 25V,+80-20,Y5V, ROHS C104 ECJ-2FB1E225K 1 PANASONIC CAP, SMD, 0805, 2.2µF, 25V, 10%, X5R, ROHS C112, C115 C1206X5R250-106KNE 2 VENKEL CAP, SMD, 1206, 10µF, 25V, 10%, X5R, ROHS C75, C109 C1206C475K3PACTU 2 KEMET CAP, SMD, 1206, 4.7µF, 25V, 10%, X5R, ROHS C79, C80, C113, C114 DNP 0 C90, C91, C92, C93 ECJ-4YB1E106M 4 PANASONIC C102, C128 25ZL1500M12.5X25 2 RUBYCON C77, C78, C110, C111 2R5TPF470M7L 4 SANYO CAP, POSCAP, SMD, 7.3X4.3, 470µF, 2.5V, 20%, 7mΩ, ROHS L6, L7 PA1513.321NLT 2 PULSE COIL-PWR INDUCTOR, SMD, 13mm, 320nH, 20%, 45A, Pb-free J2 111-0702-001 1 JOHNSON COMPONENTS CONN-GEN, BIND.POST, INSUL-RED, THMBNUT-GND J1 111-0703-001 1 JOHNSON COMPONENTS CONN-GEN,BIND.POST,INSUL-BLK, THMBNUT-GND TP20, TP32 131-4353-00 2 TEKTRONIX CONN-SCOPE PROBE TEST PT, COMPACT, PCB MNT, ROHS TP1, TP3, TP19, TP21, TP22, TP24, TP25, TP26, TP27, TP28, TP30, TP31 5002 12 KEYSTONE CONN-MINI TEST POINT, VERTICAL, WHITE, ROHS JP7, JP8, JP11, JP12 69190-202 4 BERG/FCI CONN-HEADER, 1x2, RETENTIVE, 2.54mm, ST, ROHS LED4 DNP 0 LED3 SSL-LXA3025IGC-TR 1 LUMEX U3 ISL8120IRZ 1 INTERSIL Q25 2N7002-7-F 1 DIODES, INC. Q1, Q2 DNP 0 DNP-PLACE HOLDER, TRANSIST-DUAL MOS, N-CHAN, 8P, SOIC, 30V, 6A, ROHS Q26, Q27 DNP 0 DNP-PLACE HOLDER, TRANSIST-MOSFET, N-CHAN, 5P, LFPAK, 30V, 9.4mΩ, ROHS Q32 DNP 0 DNP-PLACE HOLDER Submit Document Feedback 5 MANUFACTURER DESCRIPTION CAP, SMD, 0603, 0.22µF, 25V, 10%, X7R, ROHS CAP, SMD, 0603, DNP-PLACE HOLDER, ROHS CAP, SMD, 1206, DNP-PLACE HOLDER, ROHS CAP, SMD, 1210, 10µF, 25V, 20%, X5R, ROHS CAP, RADIAL, 12.5X25, 1500µF, 25V, 20%, ALUM.ELEC., ROHS LED, SMD, 3mmx2.5mm, 4P, RED/GREEN, 12/20MCD, 2V IC-DUAL PHASE PWM CONTROLLER, 32P, QFN, 5X5, ROHS TRANSISTOR, N-CHANNEL, 3LD, SOT-23, 60V, 115mA, ROHS AN1528.1 June 25, 2015 Application Note 1528 ISL8120EVAL3Z Bill of Materials (Continued) REFERENCE DESCRIPTION PART NUMBER QTY MANUFACTURER Q23, Q24, Q28, Q29 RJK0301DPB 4 RENESAS TECHNOLOGY TRANSISTOR, N-CHANNEL, 5P, LFPAK, 30V, 60A, ROHS Q21, Q22, Q30, Q31 RJK0305DPB 4 RENESAS TECHNOLOGY TRANSISTOR, N-CHANNEL, 5P, LFPAK, 30V, 30A, ROHS R145 CRCW06035R10FNEA 1 VISHAY/DALE RES, SMD, 0603, 5.1Ω, 1/10W, 1%, TF, ROHS 8 Various RESISTOR, SMD, 0603, 0Ω, 1/10W, TF, ROHS R96, R102, R109, R120, R152, R155, R160, R161 DESCRIPTION R116, R119, R154, R159 RK73H1JT1000F 4 KOA RES, SMD, 0603, 100Ω, 1/10W, 1%, TF, ROHS R97, R98, R115, R147 RK73H1JTTD1001F 4 KOA RES, SMD, 0603, 1k, 1/10W, 1%, TF, ROHS R123, R140, R143 RK73H1JT1002F 3 KOA RES, SMD, 0603, 10k, 1/10W, 1%, TF, ROHS R129, R136 RC0603FR-0713K7L 2 YAGEO RESISTOR, SMD, 0603, 13.7k, 1/10W, 1%, TF, ROHS R103, R157 CR0603-10W-2490FT 2 VENKEL RES, SMD, 0603, 249Ω, 1/10W, 1%, TF, ROHS R111, R142 ERJ-3EKF4021V 2 PANASONIC R135, R141 RC0603FR-074K42L 2 YAGEO RES, SMD, 0603, 4.42k, 1/10W, 1%, TF, ROHS R118, R146 CR0603-10W-45R3FT 2 VENKEL RES, SMD, 0603, 45.3Ω, 1/10W, 1%, TF, ROHS R95, R158 ERJ-3EKF6491V 2 PANASONIC RES, SMD, 0603, 6.49k, 1/10W, 1%, TF, ROHS R133 CR0603-10W-7682FT 1 VENKEL RES, SMD, 0603, 76.8k, 1/10W, 1%, TF, ROHS R99, R100, R107, R122, R124, R125, R128, R130 to R132, R149, R151, R153. DNP 0 RES, SMD, 0603, DNP-PLACE HOLDER, ROHS R94, R163 DNP 0 RES, SMD, 0805, DNP-PLACE HOLDER, ROHS R121 CR1206-4W-02R0 1 R126, R156 DNP 0 J7, J8, J9, J10 KPA8CTP 4 TP23, TP29 DNP 0 Submit Document Feedback 6 VENKEL RES, SMD, 0603, 4.02kΩ, 1/10W, 1%, TF, ROHS RES, SMD, 1206, 2Ω, 1/4W, 1%, TF, ROHS RES, SMD, 2512, PLACE HOLDER, TF, ROHS BERG/FCI HDWARE, MTG, CABLE TERMINAL, 6-14AWG, LUG&SCREW, ROHS DNP-PLACE HOLDER AN1528.1 June 25, 2015 Application Note 1528 ISL8120EVAL3Z Board Layout FIGURE 4. TOP SILKSCREEN FIGURE 5. TOP LAYER FIGURE 6. 2nd LAYER FIGURE 7. 3rd LAYER Submit Document Feedback 7 AN1528.1 June 25, 2015 Application Note 1528 ISL8120EVAL3Z Board Layout (Continued) FIGURE 8. BOTTOM LAYER FIGURE 9. BOTTOM SILKSCREEN (MIRRORED) FIGURE 10. BOTTOM SILKSCREEN Submit Document Feedback 8 AN1528.1 June 25, 2015 Application Note 1528 Test Data for ISL8120EVAL3Z Efficiency 100 100 VOUT 1 80 80 70 70 60 50 40 30 60 50 40 30 20 20 10 10 0 0 2 4 6 8 10 12 14 16 18 OUTPUT CURRENT (A) 20 22 24 VOUT 2 90 EFFICIENCY (%) EFFICIENCY (%) 90 0 26 0 2 4 6 8 10 12 14 16 18 OUTPUT CURRENT (A) 20 22 24 26 FIGURE 12. CHANNEL 2 EFFICIENCY(12V VIN AND 1.2V VOUT) FIGURE 11. CHANNEL 1 EFFICIENCY (12V VIN AND 1.2V VOUT) 1.200 1.200 1.199 1.199 1.198 CURRENT LOAD AT 25A 1.197 1.196 1.195 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 VOLTAGE OUTPUT (V) VOLTAGE OUTPUT (V) Line Regulation CURRENT LOAD AT 25A 1.198 1.197 1.196 1.195 7 8 9 10 11 FIGURE 13. CHANNEL 1 LINE REGULATION Start-up 12 13 14 15 16 17 18 19 20 21 22 23 VOLTAGE INPUT (V) VOLTAGE INPUT (V) FIGURE 14. CHANNEL 1 LINE REGULATION Load Transient VOUT1 VOUT1 VOUT2 VOUT2 FIGURE 15. POWER-UP UNDER FULL LOAD (25A FOR EACH CHANNEL) Submit Document Feedback 9 FIGURE 16. LOAD TRANSIENT (0A TO 25A STEP, SLEW_RATE = 1.6A/µs) AN1528.1 June 25, 2015 Application Note 1528 Test Data for ISL8120EVAL3Z (Continued) Output Ripple VOUT1 VOUT2 FIGURE 17. OUTPUT RIPPLES UNDER 25A LOAD FOR EACH CHANNEL DDR Application Waveforms VDDQ VDDQ PH_VDDQ VTT VTT PH_VTT FIGURE 18. VDDQ AND VTT START-UP TRACKING (DDR3) FIGURE 19. PHASE AND VOUTs (DDR3) 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 document is current before proceeding. For information regarding Intersil Corporation and its products, see www.intersil.com Submit Document Feedback 10 AN1528.1 June 25, 2015