Evaluates: MAX17531 (µMAX) in 5V Output Voltage Applications MAX17531 5V Output Evaluation Kit (µMAX) General Description The MAX17531 5V evaluation kit (EV kit) (µMAX) is a fully assembled and tested circuit board that demonstrates the performance of the MAX17531 42V, 50mA ultra-small, high-efficiency, synchronous step-down DC-DC converter in a 10-pin µMAX package. The EV kit operates over a wide input voltage range of 6V to 42V and provides up to 50mA load current at 5V output. It draws only 26µA supply current under no-load conditions (EN/UVLO connected to VIN). The EV kit is programmed to switch at a frequency of 300kHz. The device is simple to use and easily configurable with minimal external components. It features cycle-by-cycle peak current-limit protection, undervoltage lockout, and thermal shutdown. The EV kit comes installed with the MAX17531AUB+ in a 10-pin (3mm x 3mm) lead(Pb)-free/RoHS-compliant µMAX package. Features Procedure The EV kit is fully assembled and tested. Follow the steps below to verify board operation. Caution: Do not turn on the power supply until all connections are completed. 1) Verify that shunts are installed on jumpers JU1, JU2 (EN/UVLO). 2) Verify that jumper JU3 (MODE-PFM operation) is open. 3) Set the electronic load to constant-current mode, 50mA, and disable the electronic load. 4) Connect the electronic load’s positive terminal to the VOUT PCB pad. Connect the negative terminal to the GND PCB pad. 5) Connect the voltmeter across the VOUT and GND PCB pads. 6) Set the power-supply output to 24V. Disable the power supply. 7) Connect the power-supply output to the VIN PCB pad. Connect the supply ground to the GND PCB pad. ●● 6V to 42V Input Voltage Range ●● 5V Output, 50mA Continuous Current 8) Turn on the power supply. ●● 26µA No-Load Supply Current 9) ●● EN/UVLO for On/Off Control and Programmable Input Undervoltage Lockout Enable the electronic load and verify that output voltage is 5V with respect to GND. 10) Vary the input voltage from 6V to 42V. ●● Programmable Switching Frequency ●● Internal or Programmable Soft-Start ●● PFM or Forced-PWM Mode of Operation ●● Open-Drain RESET Output ●● Peak Current-Limit Protection ●● Thermal Shutdown ●● Proven PCB Layout ●● Fully Assembled and Tested 11) Vary the load current from 1mA to 50mA and verify that output voltage is 5V with respect to GND. Recommended Equipment Note: While performing an output short-circuit test, it is possible for the ceramic output capacitor to oscillate with the wiring inductance between the capacitor and shortcircuited load, and thereby cause the absolute maximum rating of the VOUT pin (-0.3V) to be exceeded. The resistor (R7) and the capacitor (C5) are included in this evaluation kit to protect against unintentional violation of the above-mentioned rating. In the actual system design, parasitic board or wiring inductance should be minimized, and the output-voltage waveform under short-circuit operation should be verified, to ensure that the absolute maximum rating of the VOUT pin is not exceeded. ●● MAX17531 5V EV kit (µMAX) ●● 42V adjustable, 0.5A DC power supply Ordering Information appears at end of data sheet. ●● Electronic load up to 50mA ●● Voltmeter Quick Start μMAX is a registered trademark of Maxim Integrated Products, Inc. 19-8759; Rev 0; 1/17 Evaluates: MAX17531 (µMAX) in 5V Output Voltage Applications MAX17531 5V Output Evaluation Kit (µMAX) RESET Output Detailed Description The MAX17531 5V EV kit (µMAX) is a fully assembled and tested circuit board that demonstrates the performance of the MAX17531 42V, 50mA ultra-small, high-efficiency, synchronous step-down DC-DC converter in a 10-pin µMAX package. The EV kit operates over a wide input voltage range of 6V to 42V and provides up to 50mA load current at 5V output. It draws only 26µA supply current under no-load conditions (EN/UVLO connected to VIN). The EV kit is programmed to switch at a frequency of 300kHz. The device is simple to use and easily configurable with minimal external components. It features cycle-by-cycle peak current-limit protection, undervoltage lockout, and thermal shutdown. The EV kit provides a PCB pad to monitor the status of the RESET output. RESET goes high when the output voltage rises above 95% (typ) of its nominal regulated output voltage. RESET goes low when output voltage falls below 92% (typ) of its nominal regulated voltage. The EV kit includes an EN/UVLO PCB pad and jumpers JU1 and JU2 to enable control of the converter output. The MODE PCB pad and jumper JU3 are provided for selecting the mode of operation of the converter. A RESET PCB pad is available for monitoring the RESET output. The RT/SYNC PCB pad can be used to synchronize the EV kit switching frequency to an external clock frequency. The EV kit offers a fixed 5ms soft-start time. Connect capacitor C4 to adjust the soft-start time (tSS). The minimum soft-start time is related to the output capacitance (COUT) and the output voltage(VOUT) by the following equation. Enable Control (JU1, JU2) The EN/UVLO pin on the EV kit serves as an on/off control while also allowing the user to program the input undervoltage-lockout (UVLO) threshold. Jumpers JU1 and JU2 configure the EV kit’s output for turn-on/turn-off control. See Table 1 for proper JU1, JU2 jumper configurations. Additionally, resistors R1 and R2 are included to set the UVLO to a desired turn-on voltage. Refer to the Setting the Input Undervoltage-Lockout Level section in the MAX17531 IC data sheet for additional information on setting the UVLO threshold voltage. PFM or Forced-PWM Mode (MODE) The EV kit includes a jumper (JU3) to select the mode of operation of the converter. Install a shunt across JU3 before powering up the EV kit to enable the forced-PWM operation. Keep JU3 open to enable the light-load PFM operation. See Table 2 for proper JU3 settings. Soft-Start tSS > 0.05 x COUT x VOUT where tSS is in milliseconds and COUT is in µF. Use the following equation to determine the soft-start capacitance value (CSS): CSS = 6.25 x tSS where tSS is in milliseconds and CSS is in nanofarads. External Synchronization (RT/SYNC) The EV kit provides a PCB pad to synchronize the EV kit switching frequency to an external clock frequency. Refer to the External Synchronization section in the MAX17531 IC data sheet for additional information on configuring the external clock. Table 1. Enable Control (EN/UVLO) (JU1, JU2) SHUNT POSITION JU1 JU2 EN/UVLO PIN VOUT OUTPUT 1-2 Open Connected to VIN Enabled Open 1-2 Connected to GND Disabled 1-2* 1-2 Connected to midpoint of R1, R2 resistor-divider Enabled at VIN ≥ 6V *Default position. Table 2. MODE Control (JU3) SHUNT POSITION MODE PIN MODE OF OPERATION 1-2 Connected to GND Forced PWM Open* Unconnected PFM *Default position. www.maximintegrated.com Maxim Integrated │ 2 Evaluates: MAX17531 (µMAX) in 5V Output Voltage Applications MAX17531 5V Output Evaluation Kit (µMAX) MAX17531 5V EV Kit (µMAX) Performance Report 80 70 70 VIN = 12V 50 EFFICIENCY (%) VIN = 36V VIN = 24V 40 30 VIN = 24V 40 VIN = 36V 30 20 10 PFM MODE 1 0 10 PWM MODE 0 LOAD CURRENT (mA) OUTPUT VOLTAGE (V) VOUT (AC) VIN = 24V VIN = 36V 4.975 4.973 30 40 FIGURE6 APPLICATION CIRCUIT VOUT=5V 4.979 VIN = 12V 20 5.05 IOUT VIN = 12V 4.99 4.96 50 VIN = 24V 5.02 0 10 20 30 40 50 LOAD CURRENT (mA) LOAD TRANSIENT RESPONSE, PFM MODE (LOAD CURRENT STEPPED FROM 2mA to 27mA) toc5 toc4 4.981 4.977 10 VIN = 36V LOAD CURRENT (mA) OUTPUT VOLTAGE vs. LOAD CURRENT 4.983 5.08 VIN = 12V 50 10 PFM MODE 5.11 60 20 0 toc3 toc2 LOAD TRANSIENT RESPONSE PFM OR PWM MODE (LOAD CURRENT STEPPED FROM 25mA TO 50mA) toc6 100mV/div VOUT (AC) 50mV/div IOUT 20mA/div 20mA/div PWM MODE 0 10 20 30 40 200µs/div 50 100µs/div LOAD CURRENT (mA) LOAD TRANSIENT RESPONSE PWM MODE (LOAD CURRENT STEPPED FROM NO LOAD TO 25mA) toc7 SOFT-START toc8 BODE PLOT 5V/div VEN/UVLO PHASE 50mV/div 2V/div VOUT IOUT 20mA/div 100µs/div www.maximintegrated.com 20mA/div IOUT VRESET GAIN (dB) VOUT (AC) toc9 fCR = 16.3kHz, PHASE MARGIN = 58° GAIN PHASE (°) EFFICIENCY (%) 90 80 60 EFFICIENCY vs. LOAD CURRENT 100 90 OUTPUT VOLTAGE (V) EFFICIENCY vs. LOAD CURRENT toc1 100 5V/div 1ms/div FREQUENCY(Hz) Maxim Integrated │ 3 Evaluates: MAX17531 (µMAX) in 5V Output Voltage Applications MAX17531 5V Output Evaluation Kit (µMAX) MAX17531 5V EV Kit (µMAX) Component Suppliers SUPPLIER WEBSITE Coilcraft, Inc. www.coilcraft.com Murata Americas www.murata.com Panasonic Corp. www.panasonic.com Note: Indicate that you are using the MAX17531AUB when contacting these component suppliers. MAX17531 5V EV Kit (µMAX) Bill of Materials Serial No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Description 22μF, 50V electrolytic capacitor (6.3mm x 6.3mm) 1μF ±10%, 50V X7R ceramic capacitor (0805) 10μF ±10%, 6.3V X7R ceramic capacitor (0805) Not installed, OPEN (0402) 0.22µF ±10%, 16V X7R ceramic capacitor (0402) 47pF ±5% 50V COG ceramic capacitor (0402) 2-pin headers 330µH, 150mA inductor 3.01M ohm ±1%, resistor (0402) 787k ohm ±1%, resistor (0402) 140k ohm ±1%, resistor (0402) 261k ohm ±1%, resistor (0402) 49.9k ohm ±1%, resistor (0402) 100k ohm ±1%, resistor (0402) 22.1 ohm ±1%, resistor (0402) 42V, 50mA, ultra-small, highefficiency, synchronous stepdown DC-DC converter with 22μA noload supply current (10 µMAX-EP*) Maxim MAX17531AUB+ Quantity 1 1 1 0 1 1 3 1 1 1 1 1 1 1 1 Designator C1 C2 C3 C4 C5 C6 JU1-JU3 L1 R1 R2 R3 R4 R5 R6 R7 Part Number PANASONIC EEEFK1H220P MURATA GRM21BR71H105K Murata GRM21BR70J106K 1 U1 MAX17531AUB+ Shunt 3 See Jumper Table SULLINS STC02SYAN 17 JUMPER JU1 JU2 JU3 www.maximintegrated.com Murata GRM155R71C224K MURATA GRM1555C1E470J Sullins: PTC36SAAN Coilcraft LPS5030-334M Jumper Table SHUNT POSITION 1‐2 1‐2 OPEN Maxim Integrated │ 4 MAX17531 5V Output Evaluation Kit (µMAX) Evaluates: MAX17531 (µMAX) in 5V Output Voltage Applications MAX17531 5V EV Kit (µMAX) PCB Layout Diagrams MAX17531 5V EV Kit (µMAX) Component Placement Guide— Component Side MAX17531 5V EV Kit (µMAX) PCB Layout—Component Side MAX17531 5V EV Kit (µMAX) PCB Layout—Solder Side www.maximintegrated.com Maxim Integrated │ 5 GND EN/UVLO C1 22UF GND 50V R2 787K JU2 JU1 R1 3.01M 2 1 1 2 VIN 6V TO 42V RT/SYNC JU3 MODE R3 140K C6 47PF C2 1UF 50V 1 www.maximintegrated.com 2 C4 OPEN 9 LX GND RT/SYNC SS MODE 8 RESET FB 7 5 6 10 EN/UVLO VOUT VIN 3 4 2 1 U1 MAX17531AUB+ C5 0.22UF 330UH L1 R6 VOUT 100K 22.1 R7 C3 10UF 6.3V RESET 49.9K R5 R4 261K VOUT GND VOUT 5V,50MA MAX17531 5V Output Evaluation Kit (µMAX) Evaluates: MAX17531 (µMAX) in 5V Output Voltage Applications MAX17531 5V EV Kit (µMAX) Schematic Maxim Integrated │ 6 + Evaluates: MAX17531 (µMAX) in 5V Output Voltage Applications MAX17531 5V Output Evaluation Kit (µMAX) Ordering Information PART MAX17531AUBEVKIT# TYPE EV Kit #Denotes RoHS compliant. www.maximintegrated.com Maxim Integrated │ 7 MAX17531 5V Output Evaluation Kit (µMAX) Evaluates: MAX17531 (µMAX) in 5V Output Voltage Applications Revision History REVISION NUMBER REVISION DATE 0 1/17 DESCRIPTION Initial release PAGES CHANGED — For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com. 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. © 2017 Maxim Integrated Products, Inc. │ 8