User Guide 057 ISL8117ADEMO1Z Demonstration Board User Guide Description Key Features The ISL8117ADEMO1Z demonstration board (shown in Figure 4) features the ISL8117A. The ISL8117A 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 keeps 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 • Wide input range: 4.5V to 60V • 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 The ISL8117ADEMO1Z demonstration board is designed for high current applications. The current rating of the ISL8117ADEMO1Z is limited by the FETs and inductor selected. The electrical ratings of ISL8117ADEMO1Z are shown in Table 1. References • ISL8117A datasheet Ordering Information TABLE 1. ELECTRICAL RATINGS PARAMETER Input Voltage RATING PART NUMBER 4.5V to 60V ISL8117ADEMO1Z Switching Frequency 300kHz Output Voltage 3.3V Output Current 6A OCP Set Point Minimum 8A at ambient room temperature VIN DESCRIPTION High voltage PWM step-down synchronous buck controller VOUT UGATE LGATE/OCS ISL8117A MOD/SYNC EN DISABLE CCM VCC5C DEM FIGURE 1. ISL8117ADEMO1Z BLOCK DIAGRAM December 22, 2015 UG057.0 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 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 057 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 Evaluating the Other Output Voltages The ISL8117ADEMO1Z kit output is preset to 3.3V, however, the output can be adjusted from 1.8V to 5V. The output voltage programming resistor, R2 , will depend on the desired output voltage of the regulator and the value of the feedback resistor R1, as shown in Equation 1. 0.6 R 2 = R 1 ------------------------------ V – 0.6 (EQ. 1) OUT • Digital Multimeters (DMMs) • 100MHz quad-trace oscilloscope Quick Test Guide 1. Ensure that the circuit is correctly connected to the supply and electronic loads prior to applying any power. Please refer to Figure 3, on page 3 for proper setup. Table 2 shows the component selection that should be used for the respective VOUT of 1.8V, 3.3V and 5V. TABLE 2. EXTERNAL COMPONENT SELECTION VOUT (V) R2 (kΩ) 1.8 24.9 3.3 11 5 6.8 2. Turn on the power supply. 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 2 for proper test setup. OUTPUT CAP OUTPUT OUTPUT CAP CAP OR ORMOSFET MOSFET FIGURE 2. PROPER PROBE SETUP TO MEASURE OUTPUT RIPPLE AND PHASE NODE RINGING Functional Description The ISL8117ADEMO1Z is a compact design with high efficiency and high power density. As shown in Figure 3, 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. Operating Range PCB Layout Guidelines Careful attention to layout requirements is necessary for successful implementation of an ISL8117A based DC/DC converter. The ISL8117A 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 ISL8117A: • The controller • The switching power components • 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. 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. The operating temperature range of ISL8117A is -40°C to +125°C. Please note that airflow is needed. Submit Document Feedback 2 UG057.0 December 22, 2015 User Guide 057 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 recommended 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. 7. Place the gate drive components (optional BOOT diode and BOOT capacitors) together near the controller IC. 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 the 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. - + A + + VIN - LOAD VO V + - A - FIGURE 3. PROPER TEST SETUP ISL8117ADEMO1Z Demonstration Board FIGURE 4. ISL8117ADEMO1Z TOP SIDE Submit Document Feedback 3 FIGURE 5. ISL8117ADEMO1Z BOTTOM SIDE UG057.0 December 22, 2015 5 & 8* 3*22' - 3+$6( & X9 %8..(; 4 / ,6/$ X$ & - YFF Q9 9287 & & SY X9 - *1' & S9 & & & 5 X9 & S9 X9 X)9 & X9 3*1' YFF & 9&&9 )% &203 6675. /*$7(2&6 ,6(1 X9 5 5 N 5 N 5 N 5 . FIGURE 6. ISL8117ADEMO1Z SCHEMATIC User Guide 057 5 N 5 . 57 X9 - & 9,1 *1' %227 02'6<1& & X9 X9 & 5 9,1 (1 (;7%,$6 4 8 & X9 & X9 X9 6*1' Submit Document Feedback Schematic UG057.0 December 22, 2015 User Guide 057 ISL8117ADEMO1Z Bill of Materials MANUFACTURER PART QTY UNITS REFERENCE DESIGNATOR ISL8117ADEMO1ZREVAPCB 1 ea. 06035C102KAT2A 1 ea. GRM188R71E104KA01D 1 ECJ1VB0J105K DESCRIPTION MANUFACTURER PWB-PCB, ISL8117ADEMO1Z, REVA, ROHS IMAGINEERING INC C17 CAP, SMD, 0603, 1000pF, 50V, 10%, X7R, ROHS AVX ea. C7 CAP, SMD, 0603, 0.1µF, 25V, 10%, X7R, ROHS MURATA 1 ea. C8 CAP, SMD, 0603, 1µF, 6.3V, 10%, X5R, ROHS PANASONIC C1608C0G1H121J080AA 1 ea. C5 CAP, SMD, 0603, 120pF, 50V, 5%, C0G, ROHS TDK C0603C0G500-220JNE 1 ea. C16 CAP, SMD, 0603, 22pF, 50V, 5%, C0G, ROHS VENKEL C1608X7R1E224K 1 ea. C2 CAP, SMD, 0603, 0.22µF, 25V, 10%, X7R, ROHS TDK VJ0603Y471KXBA 1 ea. C6 CAP, SMD, 0603, 470pF, 100V, 10%, X7R, ROHS VISHAY GRM188R71E473KA01D 1 ea. C3 CAP, SMD, 0603, 0.047µF, 25V, 10%, X7R, ROHS MURATA C0603X5R100-475KNE 1 ea. C1 CAP, SMD, 0603, 4.7µF, 10V, 10%, X5R, ROHS GRM21BR72A474KA73L 1 ea. C4 CAP, SMD, 0805, 0.47µF, 100V, 10%, X7R, ROHS MURATA 12106D107KAT2A 2 ea. C9, C10 CAP, SMD, 1210, 100µF, 6.3V, 10%, X5R, ROHS AVX CGA6M3X7S2A475K200AB 5 ea. C11, C12, C13, C14, C15 CAP, SMD, 1210, 4.7µF, 100V, 10%, X7S, ROHS TDK IHLP3232DZER3R3M11 1 ea. L1 COIL-PWR INDUCTOR, SMD, 8.6X8, 3.3µH, 20%, 10.5A, 14.9mΩ, ROHS VISHAY 1514-2 4 ea. J1, J2, J3, J5 CONN-TURRET, TERMINAL POST, TH, ROHS KEYSTONE ISL8117AFRZ 1 ea. U2 IC-55V SWITCHING CONTROLLER, 16P, QFN, ROHS INTERSIL BUK9K17-60EX 1 ea. Q1 TRANSIST-MOS, DUAL N-CHANNEL, SMD, 8P, 56LFPAK, 60V, 26A, ROHS NXP SEMICONDUCTOR RK73H1JT10R0F 2 ea. R6, R8 RES, SMD, 0603, 10Ω, 1/10W, 1%, TF, ROHS KOA ERJ-3RQF2R2V 1 ea. R9 RES, SMD, 0603, 2.2Ω, 1/10W, 1%, TF, ROHS PANASONIC CR0603-10W-05R1FT 1 ea. R5 RES, SMD, 0603, 5.1Ω, 1/10W, 1%, TF, ROHS VENKEL CR0603-10W-1003FT 1 ea. R7 RES, SMD, 0603, 100k, 1/10W, 1%, TF, ROHS VENKEL ERJ-3EKF1102V 1 ea. R2 RESISTOR, SMD, 0603, 11k, 1/10W, 1%, TF, ROHS PANASONIC CR0603-16W-1602FT 1 ea. R3 RES, SMD, 0603, 16k, 1/10W, 1%, TF, ROHS VENKEL RC0603FR-073KL 1 ea. R4 RES, SMD, 0603, 3k, 1/10W, 1%, TF, ROHS YAGEO CR0603-10W-4992FT 1 ea. R1 RES, SMD, 0603, 49.9k, 1/10W, 1%, TF, ROHS VENKEL ERJ-3EKF5602V 1 ea. R10 RES, SMD, 0603, 56k, 1/10W, 1%, TF, ROHS PANASONIC Submit Document Feedback 5 VENKEL UG057.0 December 22, 2015 User Guide 057 ISL8117ADEMO1Z PCB Layout A FIGURE 7. SILKSCREEN TOP FIGURE 8. TOP LAYER FIGURE 9. SECOND LAYER (SOLID GROUND) FIGURE 10. THIRD LAYER FIGURE 11. BOTTOM LAYER FIGURE 12. SILKSCREEN BOTTOM Submit Document Feedback 6 UG057.0 December 22, 2015 User Guide 057 Typical Demonstration Board Performance Curves VIN = 24V, VOUT = 3.3V, unless otherwise noted. 0.95 3.40 VIN = 12V 3.38 0.90 0.80 3.36 VIN = 24V 3.34 VOUT (V) EFFICIENCY (%) 0.85 0.75 0.70 VIN = 48V 0.65 VIN = 60V 3.30 3.28 3.24 0.55 3.22 0 1 2 3 VIN = 12V VIN = 24V 3.26 0.60 0.50 VIN = 60V 3.32 4 5 6 3.20 VIN = 48V 0 1 IOUT (A) FIGURE 13. CCM EFFICIENCY 2 3 4 5 6 IOUT (A) FIGURE 14. CCM LOAD REGULATION PHASE 20V/DIV IO = 0A 10mV/DIV LGATE 5V/DIV IO = 6A 10mV/DIV IL 2A/DIV 2µs/DIV 4µs/DIV FIGURE 15. PHASE, LGATE AND INDUCTOR CURRENT WAVEFORMS, IO = 0A FIGURE 16. OUTPUT RIPPLE, MODE = CCM VOUT 1V/DIV VOUT 1V/DIV SS 1V/DIV PHASE 20V/DIV PGOOD 5V/DIV LGATE 5V/DIV EN 5V/DIV IL 2A/DIV 20ms/DIV FIGURE 17. CCM START-UP WAVEFORMS: VOUT, SS, PGOOD, EN, IO = 0A Submit Document Feedback 7 4ms/DIV FIGURE 18. CCM START-UP WAVEFORMS: VOUT, PHASE, LGATE, IL, IO = 0A UG057.0 December 22, 2015 User Guide 057 Typical Demonstration Board Performance Curves VIN = 24V, VOUT = 3.3V, unless otherwise noted. (Continued) VOUT 2V/DIV SS 2V/DIV PGOOD 5V/DIV IL 5A/DIV 200ms/DIV FIGURE 19. SHORT-CIRCUIT WAVEFORMS 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 8 UG057.0 December 22, 2015