User Guide 031 ISL8117DEMO1Z Demonstration Board User Guide Description Key Features The ISL8117DEMO1Z demonstration board (shown in Figure 1) features the ISL8117. The ISL8117 is a 60V high voltage synchronous buck controller that offers external soft-start, independent enable functions and integrates UV/OV/OC/OT protection. Its current mode control architecture and internal compensation network keep peripheral component count minimal. Programmable switching frequency ranging from 100kHz to 2MHz helps to optimize inductor size while the strong gate driver delivers up to 30A for the buck output. • Small, compact design Specifications • PGOOD indicator The ISL8117DEMO1Z demonstration board is designed for high current applications. The current rating of the ISL8117DEMO1Z is limited by the FETs and inductor selected. The electrical ratings of ISL8117DEMO1Z are shown in Table 1. Input Voltage • High light-load efficiency in pulse skipping DEM operation • Programmable soft-start • Optional DEM/CCM operation • Supports prebias output with SR soft-start • External frequency sync • OCP, OVP, OTP, UVP protection References • ISL8117 datasheet Ordering Information TABLE 1. ELECTRICAL RATINGS PARAMETER • Wide input range: 4.5V to 60V RATING PART NUMBER 4.5V to 60V ISL8117DEMO1Z Switching Frequency 600kHz Output Voltage 3.3V Output Current 6A OCP Set Point Minimum 8A at ambient room temperature DESCRIPTION High Voltage PWM Step-Down Synchronous Buck Controller Recommended Testing Equipment The following materials are recommended to perform testing: • 0V to 60V power supply with at least 10A source current capability • Electronic loads capable of sinking current up to 10A • Digital Multimeters (DMMs) • 100MHz quad-trace oscilloscope FIGURE 1. ISL8117DEMO1Z DEMONSTRATION BOARD TOP May 22, 2015 UG031.0 1 FIGURE 2. ISL8117DEMO1Z DEMONSTRATION BOARD BOTTOM 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 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. User Guide 031 Quick Test Guide Operating Range 1. Ensure that the circuit is correctly connected to the supply and electronic loads prior to applying any power. Please refer to Figure 4 for proper setup. The input voltage range is from 4.5V to 60V for an output voltage of 3.3V. The rated load current is 6A with the OCP point set at minimum 8A at room temperature ambient conditions. 2. Turn on the power supply. The temperature operating range of ISL8117 is -40°C to +125°C. Please note that airflow is needed for higher temperature ambient conditions. 3. Adjust input voltage VIN within the specified range and observe output voltage. The output voltage variation should be within 3%. 4. Adjust load current within the specified range and observe output voltage. The output voltage variation should be within 3%. 5. Use an oscilloscope to observe output voltage ripple and phase node ringing. For accurate measurement, please refer to Figure 3 for proper test setup. OUTPUT CAP OUTPUT OUTPUT CAP CAP OR ORMOSFET MOSFET FIGURE 3. PROPER PROBE SETUP TO MEASURE OUTPUT RIPPLE AND PHASE NODE RINGING Functional Description The ISL8117DEMO1Z is a compact design with high efficiency and high power density. As shown in Figure 4 on page 3, 4.5V to 60V VIN is supplied to J1 (+) and J2 (-). The regulated 3.3V output on J3 (+) and J5 (-) can supply up to 6A to the load. Submit Document Feedback 2 Layout Guidelines Careful attention to layout requirements is necessary for successful implementation of an ISL8117 based DC/DC converter. The ISL8117 switches at a very high frequency and therefore the switching times are very short. At these switching frequencies, even the shortest trace has significant impedance. Also, the peak gate drive current rises significantly in an extremely short time. Transition speed of the current from one device to another causes voltage spikes across the interconnecting impedances and parasitic circuit elements. These voltage spikes can degrade efficiency, generate EMI and increase device overvoltage stress and ringing. Careful component selection and proper PC board layout minimizes the magnitude of these voltage spikes. There are three sets of critical components in a DC/DC converter using the ISL8117: the controller, the switching power components and the small signal components. The switching power components are the most critical from a layout point of view because they switch a large amount of energy which tends to generate a large amount of noise. The critical small signal components are those connected to sensitive nodes or those supplying critical bias currents. A multilayer printed circuit board is recommended. UG031.0 May 22, 2015 User Guide 031 Layout Considerations 1. The input capacitors, upper FET, lower FET, inductor and output capacitor should be placed first. Isolate these power components on dedicated areas of the board with their ground terminals adjacent to one another. Place the input high frequency decoupling ceramic capacitors very close to the MOSFETs. 2. If signal components and the IC are placed in a separate area to the power train, it is recommend to use full ground planes in the internal layers with shared SGND and PGND to simplify the layout design. Otherwise, use separate ground planes for power ground and small signal ground. Connect the SGND and PGND together close to the IC. DO NOT connect them together anywhere else. 3. The loop formed by the input capacitor, the top FET and the bottom FET must be kept as small as possible. 4. Ensure the current paths from the input capacitor to the MOSFET, to the output inductor and the output capacitor are as short as possible with maximum allowable trace widths. 5. Place the PWM controller IC close to the lower FET. The LGATE connection should be short and wide. The IC can be best placed over a quiet ground area. Avoid switching ground loop currents in this area. 6. Place VCC5V bypass capacitor very close to the VCC5V pin of the IC and connect its ground to the PGND plane. A 8. The output capacitors should be placed as close to the load as possible. Use short wide copper regions to connect output capacitors to load to avoid inductance and resistances. 9. Use copper filled polygons or wide but short trace to connect the junction of upper FET, lower FET and output inductor. Also keep the PHASE node connection to the IC short. DO NOT unnecessarily oversize the copper islands for the PHASE node. Since the phase nodes are subjected to very high dv/dt voltages, the stray capacitor formed between these islands and the surrounding circuitry will tend to couple switching noise. 10. Route all high speed switching nodes away from the control circuitry. 11. Create a separate small analog ground plane near the IC. Connect the SGND pin to this plane. All small signal grounding paths including feedback resistors, current limit setting resistor, soft-starting capacitor and EN pull-down resistor should be connected to this SGND plane. 12. Separate the current sensing trace from the PHASE node connection. 13. Ensure the feedback connection to the output capacitor is short and direct. - VO + - + VIN LOAD + 7. Place the gate drive components (optional BOOT diode and BOOT capacitors) together near the controller IC. V + - A - FIGURE 4. PROPER TEST SETUP Submit Document Feedback 3 UG031.0 May 22, 2015 User Guide 031 Typical Demonstration Board Performance Curves VIN = 24V, VOUT = 3.3V, unless 100 3.45 90 3.43 80 3.41 70 60 VIN = 60V VIN = 24V VIN = 12V 50 VIN = 6V 40 3.33 20 3.29 10 3.27 1 2 3 4 5 3.25 6 VIN = 12V 0 1 2 3 IOUT (A) 3.45 90 3.43 VIN = 12V VIN = 6V VOUT (V) EFFICIENCY (%) VIN = 48V 40 VIN = 60V 3.29 10 3.27 2 3 4 5 6 VIN = 6V 3.33 20 1 7 3.35 3.31 0 VIN = 48V 3.37 30 0 VIN = 24V 3.39 50 6 3.41 VIN = 24V 60 5 FIGURE 6. CCM LOAD REGULATION 100 70 4 VIN = 60V IOUT (A) FIGURE 5. CCM EFFICIENCY vs LOAD 80 VIN = 6V 3.35 3.31 0 VIN = 48V 3.37 30 0 VIN = 24V 3.39 VIN = 48V VOUT (V) EFFICIENCY (%) otherwise noted. 3.25 IOUT (A) VIN = 12V 0 1 2 3 4 VIN = 60V 5 6 7 IOUT (A) FIGURE 7. DEM EFFICIENCY vs LOAD FIGURE 8. DEM LOAD REGULATION PHASE 20V/DIV LGATE 5V/DIV CLKOUT 5V/DIV IL 5A/DIV 1µs/DIV FIGURE 9. PHASE, LGATE, CLKOUT AND INDUCTOR CURRENT WAVEFORMS, VIN = 24V, IO = 6A Submit Document Feedback 4 UG031.0 May 22, 2015 User Guide 031 Typical Demonstration Board Performance Curves VIN = 24V, VOUT = 3.3V, unless otherwise noted. (Continued) VOUT 10mV/DIV, VIN = 24V, IO = 0A VOUT 10mV/DIV, VIN = 24V, IO = 0A 2ms/DIV VOUT 10mV/DIV, VIN = 24V, IO = 6A VOUT 10mV/DIV, VIN = 24V, IO = 6A 4µs/DIV 2µs/DIV FIGURE 10. OUTPUT RIPPLE, CCM MODE VOUT 2V/DIV FIGURE 11. OUTPUT RIPPLE, DEM MODE VOUT 2V/DIV LGATE 5V/DIV LGATE 5V/DIV CLKOUT 5V/DIV CLKOUT 5V/DIV IL 1A/DIV IL 2A/DIV 4ms/DIV 4ms/DIV FIGURE 12. CCM START-UP WAVEFORMS: VIN = 24V, IO = 0A FIGURE 13. DEM START-UP WAVEFORMS: VIN = 24V, IO = 0A VOUT 2V/DIV VOUT 2V/DIV SS 2V/DIV SS 2V/DIV EN 5V/DIV EN 5V/DIV PGOOD 5V/DIV PGOOD 5V/DIV 10ms/DIV 10ms/DIV FIGURE 14. CCM START-UP WAVEFORMS: VIN = 24V, IO = 0A FIGURE 15. DEM START-UP WAVEFORMS: VIN = 24V, IO = 0A Submit Document Feedback 5 UG031.0 May 22, 2015 User Guide 031 Typical Demonstration Board Performance Curves VIN = 24V, VOUT = 3.3V, unless otherwise noted. (Continued) LGATE 5V/DIV SS 1V/DIV VOUT 5V/DIV PGOOD 5V/DIV 4ms/DIV FIGURE 16. TRACKING WAVEFORMS, VIN = 24V, IO = 0A VOUT 100mV/DIV CLKOUT 5V/DIV SYNC 5V/DIV IL 1A/DIV 1µs/DIV FIGURE 17. FREQUENCY SYNCHRONIZATION WAVEFORMS, VIN = 24V, IO = 0A VOUT 2V/DIV SS 2V/DIV PGOOD 5V/DIV IOUT 5A/DIV IL 10A/DIV 400µs/DIV FIGURE 18. LOAD TRANSIENT; VIN = 24V, IO = 0A TO 6A, 1A/µs, CCM MODE Submit Document Feedback 6 200ms/DIV FIGURE 19. SHORT-CIRCUIT WAVEFORMS, VIN = 24V UG031.0 May 22, 2015 Submit Document Feedback Schematic 7 User Guide 031 FIGURE 20. ISL8117DEMO1Z SCHEMATIC UG031.0 May 22, 2015 User Guide 031 ISL8117DEMO1Z Bill of Materials PART NUMBER REFERENCE DESIGNATOR QTY UNITS DESCRIPTION MANUFACTURER MANUFACTURER PART PWB-PCB, ISL8117DEMO1Z, REVB, ROHS ISL8117DEMO1ZREVAPCB SHENZHEN MULTILAYER PCB TECHNOLOGY CO., LTD C10, C11 CAP, SMD, 1210, 100µF, 6.3V, 20%, X7S, ROHS MURATA GRM32EC70J107ME15L ea C4, C22 CAP, SMD, 0603, 0.1µF, 100V, 10%, X7R, ROHS VENKEL C0603X7R101-104KNE 1 ea C25 CAP, SMD, 0603, 0.1µF, 25V, 10%, MURATA X7R, ROHS GRM39X7R104K025AD H1045-00105-6R3V10-T 4 ea C8, C9, C38, C39 CAP, SMD, 0603, 1µF, 6.3V, 10%, PANASONIC X5R, ROHS ECJ1VB0J105K H1045-00121-50V5-T 1 ea C6 CAP, SMD, 0603, 120pF, 50V, 5%, TDK C0G, ROHS C1608C0G1H121J080AA H1045-00224-25V10-T 1 ea C2 CAP, SMD, 0603, 0.22µF, 25V, 10%, X7R, ROHS TDK C1608X7R1E224K H1045-00471-100V10-T 1 ea C7 CAP, SMD, 0603, 470pF, 100V, 10%, X7R, ROHS VISHAY VJ0603Y471KXBA H1045-00473-25V10-T 1 ea C3 CAP, SMD, 0603, 0.047µF, 25V, 10%, X7R, ROHS MURATA GRM188R71E473KA01D H1046-00475-10V20-T 1 ea C1 CAP, SMD, 0805, 4.7µF, 10V, 20%, AVX X5R, ROHS 0805ZD475MAT2A H1065-00105-100V10-T 2 ea C23, C24 CAP, SMD, 1206, 1µF, 100V, 10%, VENKEL X7R, ROHS C1206X7R101-105KNE H1082-00475-100V10-T 8 ea C13, C21, C28, C29, CAP, SMD, 1210, 4.7µF, 100V, C33, C34, C35, C36 10%, X7S, ROHS H1082-DNP 0 ea C37 CAP, SMD, 1210, DNP-PLACE HOLDER, ROHS 7443340330 1 ea L1 COIL-PWR INDUCTOR, SMD, Wurth Electronics 8.4x7.9, 3.3µH, 20%, 14A, ROHS 7443340330 1514-2 4 ea J1, J2, J3, J5 CONN-TURRET, TERMINAL POST, TH, ROHS 1514-2 ISL8117FVEZ 1 ea U1 IC-55V SWITCHING CONTROLLER, INTERSIL 16P, HTSSOP, ROHS BUK9K17-60EX-T 1 ea Q1 TRANSIST-MOS, DUAL N-CHANNEL, SMD, 8P, 56LFPAK, 60V, 26A, ROHS NXP SEMICONDUCTOR BUK9K17-60EX H2511-00100-1/10W1-T 1 ea R21 RES, SMD, 0603, 10Ω, 1/10W, 1%, TF, ROHS KOA RK73H1JT10R0F H2511-002R2-1/10W1-T 2 ea R8, R9 RES, SMD, 0603, 2.2Ω, 1/10W, 1%, TF, ROHS PANASONIC ERJ-3RQF2R2V H2511-005R1-1/10W1-T 1 ea R26 RES, SMD, 0603, 5.1Ω, 1/10W, 1%, TF, ROHS VENKEL CR0603-10W-05R1FT H2511-00R00-1/10W-T 3 ea R22, R25, R28 RES, SMD, 0603, 0Ω, 1/10W, TF, VENKEL ROHS CR0603-10W-000T H2511-01003-1/10W1-T 1 ea R16 RES, SMD, 0603, 100k, 1/10W, 1%, TF, ROHS VENKEL CR0603-10W-1003FT H2511-01102-1/10W1-T 1 ea R2 RESISTOR, SMD, 0603, 11k, 1/10W, 1%, TF, ROHS PANASONIC ERJ-3EKF1102V ISL8117DEMO1ZREVAPCB 1 ea GRM32EC70J107ME15L-T 2 ea H1045-00104-100V10-T 2 H1045-00104-25V10-T Submit Document Feedback 8 TDK KEYSTONE CGA6M3X7S2A475K200AB ISL8117FVEZ UG031.0 May 22, 2015 User Guide 031 ISL8117DEMO1Z Bill of Materials PART NUMBER REFERENCE DESIGNATOR QTY UNITS (Continued) DESCRIPTION MANUFACTURER MANUFACTURER PART H2511-03001-1/10W1-T 1 ea R7 RES, SMD, 0603, 3k, 1/10W, 1%, YAGEO TF, ROHS RC0603FR-073KL H2511-04992-1/10W1-T 1 ea R1 RES, SMD, 0603, 49.9k, 1/10W, 1%, TF, ROHS CR0603-10W-4992FT H2511-DNP 0 ea R4, R5, R6, R27 RES, SMD, 0603, DNP-PLACE HOLDER, ROHS RC0603FR-0713KL 1 R3 RES SMD 13kΩ 1% 1/10W 0603 DNP 0 C40 DO NOT POPULATE OR PURCHASE ea VENKEL RC0603FR-0713KL 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 9 UG031.0 May 22, 2015 Submit Document Feedback ISL8117DEMO1Z PCB Layout 10 FIGURE 22. SECOND LAYER (SOLID GROUND) FIGURE 23. THIRD LAYER FIGURE 24. BOTTOM LAYER User Guide 031 FIGURE 21. TOP LAYER UG031.0 May 22, 2015 Submit Document Feedback ISL8117DEMO1Z PCB Layout (Continued) 11 FIGURE 26. SILKSCREEN BOTTOM User Guide 031 FIGURE 25. SILKSCREEN TOP UG031.0 May 22, 2015