MAX7536 5V Output Evaluation Kit Evaluates: MAX7536 in General Description The MAX7536 5V output evaluation kit (EV kit) provides a proven design to evaluate this high-voltage, highefficiency, synchronous step-down DC-DC converter. The EV kit is preset for a 5V output at load currents up to 4A and features a 450kHz switching frequency for optimum efficiency and component size. The EV kit features adjustable input, undervoltage lockout, adjustable soft-start, open-drain RESET signal, and external frequency synchronization. Features Operates from a 6.5V to 60V Input Supply 5V Output Voltage Up to 4A Output Current 450kHz Switching Frequency Enable/UVLO Input, Resistor-Programmable UVLO Threshold Adjustable Soft-Start Time MODE Pin to Select Among PWM, PFM, or DCM Modes Open-Drain RESET Output External Frequency Synchronization Overcurrent and Overtemperature Protection Proven PCB Layout Fully Assembled and Tested Ordering Information appears at end of data sheet. Quick Start Recommended Equipment MAX7536 5V output EV kit 6.5V to 60V, 0A DC input power supply Load capable of sinking 4A Digital voltmeter (DVM) Procedure The EV kit is fully assembled and tested. Follow the steps below to verify board operation. Caution: Do not turn on power supply until all connections are completed. ) Set the power supply at a voltage between 6V and 60V. Disable the power supply. 2) Connect the positive terminal of the power supply to the VIN PCB pad and the negative terminal to the nearest PCB pad. Connect the positive terminal of the 4A load to the VOUT PCB pad and the negative terminal to the nearest PCB pad. 3) Connect the DVM across the VOUT PCB pad and the nearest PCB pad. 4) Verify that shunt is installed across pins -2 on jumper JU (see Table for details). 5) Select the shunt position on JU2 according to the intended mode of operation (see Table 2 for details). 6) Turn on the DC power supply. 7) Enable the load. 8) Verify that the DVM displays 5V. 9-769; Rev ; 8/7
MAX7536 5V Output Evaluation Kit Evaluates: MAX7536 in Detailed Description The MAX7536 EV kit provides a proven design to evaluate the high-voltage, high-efficiency, synchronous step-down DC-DC converter. The EV kit is preset for a 5V output from a 6.5V to 60V input at load currents up to 4A and features a 450kHz switching frequency for optimum efficiency and component size. The EV kit includes an EN/UVLO PCB pad and JU to enable the output at a desired input voltage. The SYNC PCB pad allows an external clock to synchronize the device. JU2 allows the selection of a particular mode of operation based on light-load performance requirements. An additional RESET PCB pad is available for monitoring when the converter output is in regulation. Soft-Start Input (SS) The device utilizes an adjustable soft-start function to limit inrush current during startup. The soft-start time is adjusted by the value of the external capacitor from SS to GND (C7). The selected output capacitance (C SEL ) and the output voltage (V OUT ) determine the minimum value of C7, as shown by the following equation: C7 28 x 0-6 x C SEL x V OUT The soft-start time (t SS ) is related to C7 by the following equation: t SS = C7/(5.55 x 0-6) For example, to program a 2.2ms soft-start time, C7 should be 2nF. Regulator Enable/Undervoltage-Lockout Level (EN/UVLO) The device offers an adjustable-input, undervoltagelockout level. For normal operation, a shunt should be installed across pins -2 on JU. To disable the output, install a shunt across pins 2-3 on JU and the EN/UVLO pin is pulled to GND. See Table for JU settings. Set the voltage at which the device turns on with the resistive voltage-divider R/R2 connected from VIN_ to. Connect the center node of the divider to EN/ UVLO. Choose R to be 3.32MΩ and then calculate R2 as follows: R2 = R x.25 VINU -.25 where VINU is the voltage at which the device is required to turn on. Mode/SYNC Selection (MODE) The device s MODE pin can be used to select among the PWM, PFM, or DCM modes of operation. The logic state of the MODE pin is latched when the V CC and EN/UVLO voltages exceed the respective UVLO rising thresholds and all internal voltages are ready to allow LX switching. State changes on the MODE pin are ignored during normal operation. Refer to the MAX7536IC data sheet for more information on the PWM, PFM, and DCM modes of operation. Table 2 lists JU2 jumper settings that can be used to configure the desired mode of operation. The internal oscillator of the device can be synchronized to an external clock signal on the SYNC pin. The external synchronization clock frequency must be between.f SW and.4f SW, where f SW is the frequency of operation set by R5. The minimum external clock high pulse width should be greater than 50ns, while the minimum external clock low pulse width should be greater than 60ns. Table. Regulator Enable (EN/UVLO) Description (JU) SHUNT POSITION *Default position. Table 2. MODE Description (JU2) *Default position. EN/UVLO PIN MAX7536_ OUTPUT -2* Connected to VIN Enabled Not installed Connected to the center node of resistor-divider R and R2 Enabled, UVLO level set through the R and R2 resistors 2-3 Connected to Disabled SHUNT POSITION MODE PIN MAX7536_ MODE Not installed -2 2-3* Unconnected Connected to Connected to VCC PFM mode of operation PWM mode of operation DCM mode of operation Note: Bypass VCC with a 2.2μF/0V/X7R/0603 (GRM88R7A225KE5) ceramic capacitor to in PWM and DCM mode and 0μF/0V/X7R/0805 (C202X7RA06K25AC) ceramic capacitor in PFM mode. Maxim Integrated 2
MAX7536 5V Output Evaluation Kit Evaluates: MAX7536 in EV Kit Performance Report (Input voltage = 24V, unless otherwise noted.) OUTPUT VOLTAGE (V) 5.02 5.0 5.00 4.99 4.98 4.97 4.96 4.95 4.94 5V OUTPUT, PWM MODE, LOAD AND LINE REGULATION V IN = 2V V IN = 24V V IN = 36V 4.93 MODE = 4.92 0 2 3 4 LOAD CURRENT (A) V IN = 48V EFFICIENCY (%) 00 90 80 70 60 50 5V OUTPUT, PWM MODE, EFFICIENCY vs. LOAD CURRENT V IN = 2V V IN = 36V V IN = 24V MODE = 40 0 2 3 4 LOAD CURRENT (A) V IN = 48V OUTPUT VOLTAGE (V) 5.25 5.2 5.5 5. 5.05 5 4.95 4.9 4.85 5V OUTPUT, PFM MODE, LOAD AND LINE REGULATION V IN = 48V V IN = 24V V IN = 2V V IN = 36V 4.8 MODE = OPEN 4.75 0 000 2000 3000 4000 LOAD CURRENT (ma) EFFICIENCY (%) 00 90 80 70 60 50 5V OUTPUT, PFM MODE, EFFICIENCY vs. LOAD CURRENT V IN = 2V V IN = 24V V IN = 36V MODE = OPEN 40 0 00 000 0000 LOAD CURRENT (ma) V IN = 48V EFFICIENCY (%) 00 90 80 70 60 5V OUTPUT, DCM MODE, EFFICIENCY vs. LOAD CURRENT V IN = 24V V IN = 2V V IN = 48V V IN = 36V V OUT (AC) 5V OUTPUT, PWM MODE (LOAD CURRENT STEPPED FROM NO LOAD TO 2A) 00mV/div 50 40 I OUT A/div MODE = VCC 30 0 00 000 0000 LOAD CURRENT (ma) 40μs/div MODE = Maxim Integrated 3
MAX7536 5V Output Evaluation Kit Evaluates: MAX7536 in EV Kit Performance Report (continued) (Input voltage = 24V, unless otherwise noted.) 5V OUTPUT, PFM MODE (LOAD CURRENT STEPPED FROM 5mA TO 2A) 5V OUTPUT, DCM MODE (LOAD CURRENT STEPPED FROM 50mA TO 2A) V OUT (AC) 00mV/div V OUT (AC) 00mV/div I OUT MODE = OPEN A/div I OUT MODE = VCC A/div 400us/div 200μs/div 5V OUTPUT, PWM MODE (LOAD CURRENT STEPPED FROM 2A TO 4A) 5V OUTPUT, 4A LOAD CURRENT, BODE PLOT V OUT (AC) 00mV/div GAIN (db) CROSSOVER FREQUENCY = 53.2KHz, PHASE MARGIN = 64.3 PHASE ( ) I OUT 2A/div 40μs/div FREQUENCY (Hz) Maxim Integrated 4
MAX7536 5V Output Evaluation Kit Evaluates: MAX7536 in Component Suppliers Coilcraft, Inc. SUPPLIER www.coilcraft.com WEBSITE TDK Corp. www.tdk.com Murata Americas www.murata.com Panasonic Corp. www.panasonic.com Vishay www.vishay.com Note: Indicate that you are using the MAX7536when contacting these component suppliers. Ordering Information PART TYPE MAX7536EVKITB# #Denotes RoHS compliant. EV Kit MAX7536 5V Output EV Kit Bill of Materials Serial No. Description Quantity Designator Part Number 2.2μF ±0%, 00V X7R ceramic capacitor (20) 2 C, C2 MURATA GRM32ER72A225KA35 2 0.μF ±0%, 00V X7R ceramic capacitor (0603) 3 C3,C4,C3 MURATA GRM88R72A04KA35 3 47uF 80V aluminum electrolytic (D=0mm) C5 PANASONIC EEEFKK470P 4 2.2μF ±0%, 0V X7R ceramic capacitor (0603) C6 MURATA GRM88R7A225K 5 22000pF ±0%, 50V X7R ceramic capacitor (0402) C7 MURATA GRM55R7H223K 6 47uF ±0%, 0V X7R ceramic capacitor (20) C8 MURATA GRM32ER7A476K 7 22uF ±0%, 0V X7R ceramic capacitor (20) C9,C0 MURATA GRM32ER7A226K 8 0.μF ±0%, 50V X7R ceramic capacitor (0402) C,C3 MURATA GRM55R7H04KE4 3-pin header (36-pin header 0. centers ) 2 JU, JU2 Sullins: PTC36SAAN 2 4.7uH Inductor (6.36mm x 6.56mm x 6.mm) L Coilcraft XAL6060-472 3 MOSFET (80V, 30A) N VISHAY SILICONIX: SIS468DN-T-GE3 4 3.32M ohm ±%, resistor (0603) R 5 604k ohm ±%, resistor (0603) R2 6 96k ohm ±%, resistor (0402) R3 7 43.2k ohm ±%, resistor (0402) R4 8 Not installed, OPEN (0402) 0 R5 9 0k ohm ±%, resistor (0402) R6 20 Not installed, OPEN (0402) 0 R7 2 4.7 ohm ±%, resistor (0402) R8,R9 22 Buck Converter MAX7536ATP+ U MAX7536ATP+ 23 Shunt 2 See Jumper Table SULLINS STC02SYAN JUMPER TABLE JUMPER SHUNT POSITION JU -2 JU2 2-3 Maxim Integrated 5
MAX7536 5V Output Evaluation Kit Evaluates: MAX7536 in MAX7536 5V Output EV Kit Schematic VIN C5 47UF 80V C 2.2UF 00V C2 2.2UF 00V C3 0.UF 00V C4 C4 0.UF 0.UF 00V 00V VCC C6 2.2UF MODE/SYNC RESETB 4.7UH VOUT C 0.UF 47UF 0V R9 4.7 R7 OPEN VIN VIN VIN 5 2 VIN VIN 4 MAX7536 EN/UVLO 3 VCC SS 2 R8 4.7 C3 0.UF EN/UVLO C7 0.022UF VOUT R6 0K C2 VOUT OPEN R3 R5 96K OPEN R4 43.2K VCC 22UF 0V C0 22UF 0V VOUT VIN 3.32M 23 604K JU 2 + VIN JU2 3 2 N 8 7 6 5 L 2 3 2 C8 U C9 R R2 6 7 8 9 0 BST 20 9 7 8 6 4 EN/UVLO EN/UVLO 3 4 5 FB DL LX LX LX MODE/SYNC EXTVCC RESETB RT CF EP G D S Maxim Integrated 6
MAX7536 5V Output Evaluation Kit Evaluates: MAX7536 in MAX7536 5V Output EV Kit PCB Layout MAX7536 5V Output EV Kit PCB Layout Top Silkscreen MAX7536 5V Output EV Kit PCB Layout Top Layer Maxim Integrated 7
MAX7536 5V Output Evaluation Kit Evaluates: MAX7536 in MAX7536 5V Output EV Kit PCB Layout (continued) MAX7536 5V Output EV Kit PCB Layout Layer 2 Ground MAX7536 5V Output EV Kit PCB Layout Layer 3 Power Maxim Integrated 8
MAX7536 5V Output Evaluation Kit Evaluates: MAX7536 in MAX7536 5V Output EV Kit PCB Layout (continued) MAX7536 5V Output EV Kit PCB Layout Bottom Layer Maxim Integrated 9
MAX7536 5V Output Evaluation Kit Evaluates: MAX7536 in Revision History REVISION NUMBER REVISION DATE DESCRIPTION PAGES CHANGED 0 6/5 Initial release 8/7 Updated Quick Start, Detailed Description, and Soft-Start Input (SS) section. Updated Table 2 and Component Suppliers table. Replaced Bill of Materials, Schematic, and PCB Layout diagrams. 2, 5 9 For pricing, delivery, and ordering information, please contact Maxim Direct at -888-629-4642, or visit Maxim Integrated s website at. Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc. 207 Maxim Integrated Products, Inc. 0