User Guide 024 ISL85403EVAL1Z Evaluation Board User Guide Description Key Features The ISL85403EVAL1Z board allows quick evaluation of the ISL85403 in the 2-stage boost-buck and the synchronous buck configurations. It is a cost effective solution for the low-power, wide input voltage range point-of-load application where both stepping up and stepping down voltage capabilities are required. • Flexible design • Convenient power connection Specifications ISL85403 Datasheet The design specifications of the ISL85403EVAL1Z are shown in Table 1. TABLE 1. SPECIFICATIONS PARAMETERS 4V to 40V Output Voltage (VOUT) 5.0V Max. Output Current (IOUT_MAX) 2.5A Switching Frequency Ordering Information ISL85403EVAL1Z DESCRIPTION ISL85403 Evaluation Board, 2-stage boost-buck configuration 5V output 500kHz Output Ripple 40mV FIGURE 1. TOP VIEW March 4, 2015 UG024.0 References PART NUMBER VALUES Input Voltage (VIN) • VIN range of 4V to 40V 1 FIGURE 2. BOTTOM VIEW 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 024 Functional Description The ISL85403 is a flexible switching regulator with an integrated 127mΩ high-side MOSFET. It can be used as a synchronous buck converter, a 2-stage boost-buck converter or a noninverting buck-boost converter. The ISL85403EVAL1Z board demonstrates the operations of the ISL85403 in the 2-stage boost-buck configuration. It also allows the user to easily modify the board into synchronous buck configuration. The ISL85403EVAL1Z board is shown in Figures 1 and 2. The schematic is shown on page 4, bill of materials on page 5, and PCB layers for reference start on page 9. Figures 6 through 25 show performance data taken from the evaluation board. 2. Connect the power supply to the input terminals VBAT(J5) and GND (J6). Connect the load terminals to the output VOUT+ (J10) and GND (J11). Make sure the setup is correct prior to applying any power or load to the board. 3. Adjust the power supply to 4V to 40V and turn it on. 4. Verify the output voltage is 5V and use oscilloscope to monitor the phase node waveforms. Board Modification for the Synchronous Buck Configuration The following steps provide guidelines to modify the ISL85403EVAL1Z into the synchronous buck configuration. 1. Populate Q1 with the desired MOSFET. Operating Range 2. Remove the jumper on J16 to disconnect the boost power stage from the buck power stage For the 2-stage boost-buck configuration, the board input voltage range is 4V to 40V. The output voltage is set to 5V by default and can be changed by voltage feedback resistors R3 and R4, as shown in Equation 1: 3. Populate R32 with 0Ω resistor and R5 with 4.7kΩresistor. 4. Remove resistor R22. V ref R 4 = R 3 -------------------------------V OUT – v ref (EQ. 1) NOTE: In order to change to a higher output voltage, the output capacitors have to be changed for the higher voltage rating. The board is set to a default frequency of 500kHz (FS pin/R8 is open). The switching frequency can be programmed to other values by a resistor at R8. Refer to the ISL85403 datasheet for the resistor value and the switching frequency. The switching frequency can also be synchronized to external clock by connecting the external clock to the SYNC terminal (J13). Quick Test Setup 5. Short EXT_BOOST pin to ground by removing R31 and replacing R30 with 0Ωresistor 6. If VCC switch-over feature is needed, remove the resistors R28 and R29 and populate R6 with 0Ωresistor. 7. Removing the diode D1 is optional. Generally the SS3P6 will help reducing losses associated with the MOSFET’s body diode, yielding better efficiency. 1. Connect the power supply to the input terminals VIN+ (J8) and GND (J9). Connect the load terminals to the output VOUT+ (J10) and GND (J11). Make sure the setup is correct prior to applying any power or load to the board. 2. Adjust the power supply to 8V to 40V and turn it on. - LOAD + ++- - LOAD + A A FIGURE 4. ISL85403EVAL1Z IN THE SYNCHRONOUS BUCK CONFIGURATION BOARD SET UP FIGURE 3. ISL85403EVAL1Z BOARD SETUP 1. Make sure that shunt is installed on J16. Submit Document Feedback 2 UG024.0 March 4, 2015 User Guide 024 PCB Layout Guidelines 1. Place the coupling ceramic capacitors as closely as possible to the IC VIN pin and cathode of the power diode (D1). Keep this loop (coupling ceramic capacitor, IC VIN pin and diode) as small as possible to minimize the voltage spikes induced by the trace parasitic inductance. A bulk capacitor, C59 (as shown in the “ISL85403EVAL1Z Circuit Schematic” on page 4), is included to support long wire connections from power supplies to the evaluation board. 2. Keep the phase node copper area small but large enough to handle the load current. 3. Place the output ceramic and aluminum capacitors close to the power stage components as well. 4. Place vias (at least 9) in the bottom pad of the IC. The bottom pad should be placed in ground copper plane with an area as large as possible in multiple layers to effectively reduce the thermal impedance. 5. Place the 4.7µF ceramic decoupling capacitor C1 (as shown in the “ISL85403EVAL1Z Circuit Schematic” on page 4) as close as possible to the IC’s VCC pin. Put multiple vias close to the ground pad of this capacitor. 6. Keep the bootstrap capacitor close to the IC. 7. Place the output voltage sense trace close to the place that is to be strictly regulated. 8. Place all the peripheral control components close to the IC. Submit Document Feedback 3 UG024.0 March 4, 2015 Submit Document Feedback ISL85403EVAL1Z Circuit Schematic / ' - - 9287B%2267 9%$7 X+ 663 9%$7 & X) ((()..3 & X) /*$7( 9 & & X) X) 9 9 5 %6 4 177)61/7$* - 9,1 & X) 9 5 N - - 4 *1' *1' - $8;9&& 9287B%2267 5 . & X) 66 )% 5 N & S) (3 9,1 9,1 9,1 5 '13 %6 N & X) / - 3+$6( 5 '13 5 9287 5 '13 (;7B%2267 (;7B%2267 5 N 5 - 6<1& 6<1& &203 /*$7( /*$7( )% & S) &203 & S) 5 & X) ((()..3 3*1' ,6/ 66 ,/,0,7 8 )6 & X) 9 %227 3+$6( 9%$7 3+$6( )6 '13 & X) 9 %227 (1 & X) 9 (1 6*1' 5 3*22' & '13 3*22' 5 '13 9&& $8;9&& - %6 02'( ,/,0,7 ' '13 $8;9&& 5 N User Guide 024 5 '13 9&& 02'( '13 & X) 5 9287 9&& X+ '55 4 '13 ' 663 9287 N 5 '13 - %6 5Vout 2.5A & '13 & X) & X) 73(0, - *1' 5 & '13 5 5 '13 N 5 N UG024.0 March 4, 2015 FIGURE 5. ISL85403EVAL1Z SCHEMATIC User Guide 024 Bill of Materials REF DES C6 PART NUMBER QTY DESCRIPTION MANUFACTURER C1608X7R1C105K 1 CAP, SMD, 0603, 1.0µF, 16V, 10%, X7R, ROHS EEE-FK1K220P 2 CAP, SMD, 8X10.2, 22µF, 80V, 20%, ALUM.ELEC., ROHS C9 VARIOUS 1 CAP, SMD, 0603, 10pF, 50V, 5%, C0G, ROHS VARIOUS C15, C23 VARIOUS 1 CAP, SMD, 0603, 0.1µF, 50V, 10%, X7R, ROHS VARIOUS C4 VARIOUS 1 CAP, SMD, 0603, 0.015µF, 50V, 10%, X7R, ROHS VARIOUS C8 VARIOUS 1 CAP, SMD, 0603, 470pF, 50V, 5%, NP0, ROHS VARIOUS C3 C1608X7R1H474K 1 CAP, SMD, 0603, 0.47µF, 50V, 10%, X7R, ROHS C7 VARIOUS 1 CAP, SMD, 0603, 820pF, 50V, 5%, C0G, ROHS VARIOUS C14 VARIOUS 1 CAP, SMD, 0805, 1.0µF, 50V, 10%, X7R, ROHS VARIOUS C1 0805ZD475KAT2A 1 CAP, SMD, 0805, 4.7µF, 10V, 10%, X5R, ROHS AVX C22 VARIOUS 1 CAP, SMD, 1206, 10µF, 50V, 10%, X5R, ROHS VARIOUS GRM31CR71H225KA88L 3 CAP, SMD, 1206, 2.2µF, 50V, 10%, X7R, ROHS MURATA 6TPE220MI 1 CAP-POSCAP, SMD, 7.3x4.3x1.8, 220µF, 6.3V, 20%, 18mΩ, ROHS SANYO L1 DR125-100-R 1 COIL-PWR INDUCTOR, SMD, 12.5mm, 10µH, 20%, 5.35A, ROHS COILTRONICS L2 DR125-6R8-R 1 COIL-PWR INDUCTOR, SMD, 12.5mm, 6.8µH, 20%, 6.64A, ROHS COILTRONICS SS6P3LHM3/86A 2 DIODE-SCHOTTKY RECTIFIER, SMD, SMPC, 60V, 3A, ROHS U1 ISL85403IRZ 1 IC-SWITCHING REGULATOR, 20P, QFN, 4X4, ROHS INTERSIL Q2 BSZ100N06LS3G 1 TRANSIST-MOS, N-CHANNEL, 8P, PG-TSDSON-8, 60V, 20A, ROHS INFINEON R2 VARIOUS 1 RES, SMD, 0603, 220k, 1/10W, 1%, TF, ROHS VARIOUS R3 VARIOUS 1 RES, SMD, 0603, 52.3k, 1/10W, 1%, TF, ROHS VARIOUS R4, R23 VARIOUS 2 RES, SMD, 0603, 10k, 1/10W, 1%, TF, ROHS VARIOUS R7 VARIOUS 1 RES, SMD, 0603, 301k, 1/10W, 1%, TF, ROHS VARIOUS R9 VARIOUS 1 RES, SMD, 0603, 750Ω, 1/10W, 1%, TF, ROHS VARIOUS R22, R26 VARIOUS 2 RES, SMD, 0603, 0Ω, 1/10W, TF, ROHS VARIOUS R28, R31 VARIOUS 2 RES, SMD, 0603, 332k, 1/10W, 1%, TF, ROHS VARIOUS R29 VARIOUS 1 RES, SMD, 0603, 9.09k, 1/10W, 1%, TF, ROHS VARIOUS R30 VARIOUS 1 RES, SMD, 0603, 36k, 1/10W, 1%, TF, ROHS VARIOUS 0 Do not populate C57, 59 C18, C19, C25 C60 D1, D3 R1, R5, R6, R8, R24, N/A R25, R32, R33, R34, C5, C10, C61, D4, Q1 Submit Document Feedback 5 TDK PANASONIC TDK VISHAY N/A UG024.0 March 4, 2015 User Guide 024 Typical Performance Curves 5.05 100 5.04 OUTPUT VOLTAGE (V) EFFICIENCY (%) 90 80 VIN = 12V VIN = 5V 70 VIN = 24V 60 VIN = 36V 50 40 5.03 5.02 VIN = 12V 5.01 VIN = 5V 5.00 4.99 4.98 4.97 VIN = 36V VIN = 24V 4.96 0 0.5 1.0 1.5 2.0 2.5 4.95 0 0.5 FIGURE 6. EFFICIENCY vs LOAD VOUT (AC-COUPLE) 10mV/DIV 1.0 1.5 2.0 2.5 OUTPUT CURRENT (A) OUTPUT CURRENT (A) FIGURE 7. LOAD REGULATION VOUT (AC-COUPLE) 20mV/DIV IL_BUCK 2A/DIV IL_BUCK 200mA/DIV PHASE_BUCK 10V/DIV PHASE_BUCK 10V/DIV PHASE_BOOST 10V/DIV PHASE_BOOST 10V/DIV 5µs/DIV 5µs/DIV FIGURE 8. OUTPUT RIPPLE AT 0A LOAD (VIN = 5V) FIGURE 9. OUTPUT RIPPLE AT 2.5A LOAD (VIN = 5V) VOUT (AC-COUPLE) 20mV/DIV VOUT (AC-COUPLE) 10mV/DIV IL_BUCK 2A/DIV IL_BUCK 200mA/DIV PHASE_BUCK 5V/DIV PHASE_BUCK 10V/DIV PHASE_BOOST 5V/DIV PHASE_BOOST 10V/DIV 20µs/DIV 5µs/DIV FIGURE 10. OUTPUT RIPPLE AT 0A LOAD (VIN = 12V) FIGURE 11. OUTPUT RIPPLE AT 2.5A LOAD (VIN = 12V) Submit Document Feedback 6 UG024.0 March 4, 2015 User Guide 024 Typical Performance Curves (Continued) VOUT (AC-COUPLE) 20mV/DIV VOUT (AC-COUPLE) 20mV/DIV IL_BUCK 2A/DIV IL_BUCK 200mA/DIV PHASE_BUCK 10V/DIV PHASE_BUCK 20V/DIV PHASE_BOOST 20V/DIV PHASE_BOOST 10V/DIV 20µs/DIV 5µs/DIV FIGURE 12. OUTPUT RIPPLE AT 0A LOAD (VIN = 24V) FIGURE 13. OUTPUT RIPPLE AT 2.5A LOAD (VIN = 24V) VOUT (AC-COUPLE) 20mV/DIV VOUT (AC-COUPLE) 20mV/DIV IL_BUCK 2A/DIV IL_BUCK 200mA/DIV PHASE_BUCK 20V/DIV PHASE_BUCK 20V/DIV PHASE_BOOST 20V/DIV PHASE_BOOST 20V/DIV 5µs/DIV 20µs/DIV FIGURE 14. OUTPUT RIPPLE AT 0A LOAD (VIN = 36V) VOUT (AC-COUPLE) 200mV/DIV FIGURE 15. OUTPUT RIPPLE AT 2.5A LOAD (VIN = 36V) VOUT (AC-COUPLE) 200mV/DIV VOUT_BOOST 5V/DIV IL_BUCK 1A/DIV IL_BUCK 1A/DIV 5ms/DIV 2ms/DIV FIGURE 16. LOAD TRANSIENT RESPONSE 0A<->2.5A, VIN = 5V FIGURE 17. LOAD TRANSIENT RESPONSE 0A<->2.5A, VIN = 12V Submit Document Feedback 7 UG024.0 March 4, 2015 User Guide 024 Typical Performance Curves (Continued) VOUT (AC-COUPLE) 100mV/DIV VOUT (AC-COUPLE) 100mV/DIV IL_BUCK 1A/DIV IL_BUCK 1A/DIV 2ms/DIV 2ms/DIV FIGURE 18. LOAD TRANSIENT RESPONSE 0A<->2.5A, VIN = 24V FIGURE 19. LOAD TRANSIENT RESPONSE 0A<->2.5A, VIN = 36V VOUT (AC-COUPLE) 100mV/DIV VOUT (AC-COUPLE) 100mV/DIV VOUT_BOOST 5V/DIV IL_BOOST 1A/DIV VOUT_BOOST 5V/DIV VBATT 5V/DIV IL_BOOST 1A/DIV VBATT 5V/DIV 20ms/DIV 20ms/DIV FIGURE 20. BOOST-BUCK MODE, INPUT TRANSITION FROM 12V TO 5V, 2.5A LOAD FIGURE 21. BOOST-BUCK MODE, INPUT TRANSITION FROM 5V TO 12V, 2.5A LOAD VOUT 2V/DIV VOUT 2V/DIV IL_BUCK 2A/DIV VOUT_BOOST 5V/DIV IL_BUCK 2A/DIV VOUT_BOOST 5V/DIV PHASEBUCK 5V/DIV PHASEBUCK 5V/DIV 1ms/DIV 1ms/DIV FIGURE 22. SOFT-START AT 0A LOAD (VIN = 5V) FIGURE 23. SOFT-START WITH 2Ω LOAD (VIN = 5V) Submit Document Feedback 8 UG024.0 March 4, 2015 User Guide 024 Typical Performance Curves (Continued) VOUT 2V/DIV IL_BUCK 2A/DIV VOUT 2V/DIV IL_BUCK 2A/DIV VOUT_BOOST 20V/DIV VOUT_BOOST 20V/DIV PHASEBUCK 20V/DIV PHASEBUCK 20V/DIV 1ms/DIV 1ms/DIV FIGURE 24. SOFT-START AT 0A LOAD (VIN = 36V) FIGURE 25. SOFT-START WITH 2Ω LOAD (VIN = 36V) Board Layout FIGURE 26. SILKSCREEN TOP Submit Document Feedback 9 FIGURE 27. TOP LAYER UG024.0 March 4, 2015 User Guide 024 Board Layout (Continued) FIGURE 28. 2nd LAYER FIGURE 29. 3rd LAYER FIGURE 30. BOTTOM LAYER FIGURE 31. SILKSCREEN BOTTOM 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 UG024.0 March 4, 2015