Click here to ask about the production status of specific part numbers. Evaluates: MAX17760 in MAX17760AEVKIT Evaluation Kit 5V Output-Voltage Application General Description Quick Start The MAX17760AEVKIT evaluation kit (EV kit) provides a Recommended Equipment proven design to evaluate the MAX17760 high-efficiency, MAX17760 5V output EV kit high-voltage, synchronous step-down DC-DC converter 76V, 0.5A DC input power supply in a TDFN package. The EV kit generates 5V at load currents up to 300mA from a 7V to 76V input supply. Load capable of sinking 300mA The EV kit features a 400kHz switching frequency for 2 digital voltmeters (DVM) optimum efficiency and component size. The EV kit fea - Equipment Setup and Test Procedure tures adjustable input undervoltage lockout, adjustable soft-start, adjustable switching frequency, open-drain The EV kit is fully assembled and tested. Follow the steps RESET signal, and external clock synchronization. below to verify board operation. The EV kit also provides a good layout example, which Caution: Do not turn on power supply until all is optimized for conducted, radiated EMI, and thermal connections are completed. performance. For more details about the IC benefits and 1) Set the power supply at a voltage of 5.5V. Then, features, refer to the MAX17760 IC data sheet. disable the power supply. 2) Connect the positive terminal of the power supply to Features the VIN PCB pad and the negative terminal to the Operates from a 7V to 76V Input Supply nearest PGND PCB pad. Connect the positive termi- 5V Output Voltage nal of the 300mA load to the VOUT PCB pad and the Up to 300mA Output Current negative terminal to the nearest PGND PCB pad. 3) Connect one DVM across the VOUT PCB pad and the 400kHz Switching Frequency nearest PGND PCB pad, and the other DVM across Enable/UVLO Input, Resistor-Programmable UVLO RESET PCB pad and SGND PCB pad. Threshold 4) Verify that shunts are installed across pins 12 on Adjustable Soft-Start Time jumper JU1 and JU2 (see Table 1 and Table 2 for MODE Pin to Select between PWM or PFM Modes details), and on pin 1 of JU3. Bootstrap Bias Input for Improved Efficiency 5) Turn on the DC power supply. Open-Drain RESET Output 6) Enable the load. 7) Verify that both the DVMs displays approximately 0V. External Clock Synchronization 8) Increase the input voltage to 7V, which is just above Overcurrent and Overtemperature Protection the EN/UVLO rising threshold. Proven PCB Layout 9) Verify that the DVM across the VOUT PCB pad and Fully Assembled and Tested the nearest PGND PCB pad displays 5V. Complies with CISPR22 (EN55022) Class B 10) Verify that the DVM across the RESET PCB pad and Conducted and Radiated Emissions the SGND PCB pad displays 5V. 11) The power-supply voltage can be set at any voltage Ordering Information appears at end of data sheet. between 7V and 76V and both the DVMs still read the same voltages. 12) Reduce the input voltage to 5V, which is below the EN/UVLO falling threshold. 13) Verify that both the DVMs displays approximately 0V. 14) Disable the input power supply. 319-100530 Rev 0 4/20Evaluates: MAX17760 in MAX17760AEVKIT Evaluation Kit 5V Output-Voltage Application where, V is the voltage at which the device is required INU Detailed Description to turn on, and R1 is in . Calculate the value of R2 as The MAX17760AEVKIT provides a proven design to follows: evaluate the MAX17760 high-efficiency, high-voltage, synchronous step-down DC-DC converter. The EV kit 1.215 R1 R2 = generates 5V at load currents up to 300mA from a 7V to (V 1.215 + (2.5A R1)) INU 76V input supply. The EV kit features a 400kHz switching frequency for optimum efficiency and component size. Soft-Start Input (SS) The EV kit includes an EN/UVLO PCB pad and JU1 to The EV kit offers an adjustable soft-start function to enable the output at a desired input voltage or enable the limit inrush current during startup. The soft-start time is converter through an external enable signal on the EN/ adjusted by the value of external soft-start capacitor (C6) UVLO PCB pad. The RT/SYNC PCB pad and JU3 allow connected between SS and SGND. The selected output an external clock to synchronize the device. An additional capacitance (C ) and the output voltage (V ) deter- SEL OUT RESET PCB pad is available for monitoring when the mine the minimum required soft-start capacitor as follows: converter output is in regulation. (-6) C 30 x 10 x C x V SS SEL OUT Enable/Undervoltage-Lockout The soft-start time (t ) is related to the capacitor con- SS (EN/UVLO) Programming nected at SS (C ) by the following equation: SS The MAX17760 offers an Enable and an adjustable input undervoltage lockout feature. In this EV kit, for always-on C SS t = SS operation, leave the EN/UVLO jumper (JU1) open. To 6 6.25 10 disable the MAX17760, install a shunt across pins 23 on JU1. See Table 1 for JU1 settings. The EN/UVLO PCB For example, to program a 0.9ms soft-start time, a 5.6nF pad on the EV kit supports external Enable/Disable con- capacitor should be connected from the SS pin to SGND. trol of the device. Leave JU1 open when external Enable/ Mode of Operation Selection (MODE) Disable control is desired. A potential divider formed by R1 and R2 sets the input voltage (V ) above which the The EV kit provides a jumper (JU2) that allows the INU converter is enabled when a shunt is connected across MAX17760 to operate either in PWM or PFM modes. pins 12 on JU1. Table 2 shows the mode selection (JU2) settings that can be used to configure the desired mode of operation. Refer Choose R1 as follows: to the MAX17760 IC data sheet for more details on the R1 (110000 V ) INU modes of operation. The mode of operation cannot be changed on-the-fly after Table 1. Converter EN/UVLO Jumper power-up. (JU1) Settings Table 2. Modes Selection Jumper (JU2) SHUNT MAX17760 Settings JUMPER EN/UVLO PIN POSITION OUTPUT SHUNT MODE OF Connected to the Enabled, UVLO MODE PIN POSITION OPERATION center node of level set through 1-2* resistor-divider the R1 and R2 Connected to 1-2* PWM R1 and R2 resistors SGND JU1 Not Not Installed Unconnected PFM Floating Always ON installed *Default Setting Connected to 2-3 Disabled SGND *Default Position Maxim Integrated 2 www.maximintegrated.com