Click here for production status of specific part numbers. Evaluates: MAX17632 MAX17632C5EVKITE 5V Output-Voltage Application Evaluation Kit General Description Quick Start The MAX17632C5EVKITE evaluation kit (EV kit) Recommended Equipment provides a proven design to evaluate the MAX17632C MAX17632C5EVKITE EV kit high-efficiency, synchronous step-down DC-DC convert - 6.5V to 36V, 2A DC-input power supply er. The EV kit provides 5V/2A at the output from a 6.5V to 36V input supply. The switching frequency of the EV kit is Load capable of sinking 2A preset to 400kHz for optimum efficiency and component Digital voltmeter (DVM) size. The EV kit features adjustable input undervoltage lockout, adjustable soft-start, open-drain RESET sig- Equipment Setup and Test Procedure nal, and external clock synchronization. The EV kit also The EV kit is fully assembled and tested. Follow the steps provides a good layout example, which is optimized for below to verify the board operation. conducted, radiated EMI and thermal performance. For Caution: Do not turn on power supply until all more details about the IC benefits and features, refer to connections are completed. the MAX17632 IC data sheet. 1) Set the power supply at a voltage between 6.5V and 36V. Then, disable the power supply. Features Operates from a 6.5V to 36V Input Supply 2) Connect the positive terminal of the power supply to the VIN PCB pad and the negative terminal to 5V Output Voltage the nearest PGND PCB pad. Connect the positive Delivers Up to 2A Output Current terminal of the 2A load to the VOUT PCB pad and the 400kHz Switching Frequency negative terminal to the nearest PGND PCB pad. Enable/UVLO Input, Resistor-Programmable 3) Connect the DVM across the VOUT PCB pad and the UVLO Threshold nearest PGND PCB pad. Adjustable Soft-Start Time 4) Verify that shunts are installed across pins 1-2 on jumper JU1 (see Table 1 for details) and pins 2-3 on Open-Drain RESET Output jumper JU2 (see Table 2 for details) Overcurrent and Overtemperature Protection 5) Turn on the DC power supply. Proven PCB Layout 6) Enable the load. Fully Assembled and Tested 7) Verify that the DVM displays 5V. Complies with CISPR-22(EN55022) Class B Conducted and Radiated Emissions Ordering Information appears at end of data sheet. 319-100328 Rev 0 3/19Evaluates: MAX17632 MAX17632C5EVKITE Evaluation Kit 5V Output-Voltage Application Enable/Undervoltage-Lockout (EN/UVLO) Detailed Description Programming The EV kit is designed to deliver 5V at load current up The MAX17632 offers an Enable and adjustable input to 2A at the output from a 6.5V to 36V input supply. The undervoltage-lockout feature. In this EV kit, for normal switching frequency of the EV kit is configured at 400 kHz operation, leave the EN/UVLO jumper (JU1) open. When by leaving RT resistor open. JU1 is left open, the MAX17632 is enabled when the The EV kit includes an EN/UVLO PCB pad and jumper input voltage rises above 6.4V. To disable the MAX17632, JU1 to enable the output at a desired input voltage. The install a jumper across pins 23 on JU1. See Table 1 MODE/SYNC PCB pad and jumper JU2 allow an external for JU1 settings. The EN/UVLO PCB pad on the EV kit clock to synchronize the device. Jumper JU2 allows the supports external Enable/Disable control of the device. selection of the mode of operation based on light load- Leave JU1 open when external Enable/Disable control is performance requirements. An additional RESET PCB desired. A potential divider formed by R1 and R2 sets the pad is available for monitoring whether the converter input voltage (V ) above which the converter is enabled INU output is in regulation or not. when JU1 is left open. Soft-Start Input (SS) Choose R1 to be 3.32M and then calculate R2 as follows: The EV kit offers an adjustable soft-start function to limit R1 1.215 inrush current during the startup. The soft-start time is R2 = V 1.215 adjusted by the value of external soft-start capacitor (C3) ( ) INU connected between SS and SGND. The selected output where V is voltage at which the device is required to INU capacitance (C ) and the output voltage (V ) deter- SEL OUT turn on, and R1 and R2 are in k. mine the minimum value of C3, as shown by the following equation: Mode Selection (MODE/SYNC) -6 C3 28 x 10 x C x V SEL OUT The EV kit provides a jumper (JU2) that allows the MAX17632 to operate in PWM, PFM, and DCM modes. The soft-start time (t ) is related to the soft-start capaci- SS Refer to the MAX17632 data sheet for more details on the tor C3 by the following equation: modes of operation. C3 t = SS Table 2 shows the mode selection (JU2) settings that can -6 5.55 10 ( ) be used to configure the desired mode of operation. For example, in order to program a 1ms soft-start time, C3 should be 5600pF. Table 1. Converter EN/UVLO Jumper (JU1) Settings SHUNT POSITION EN/UVLO PIN MAX17632C OUTPUT 1-2* Connected to VIN Enabled Connected to the center node of Enabled, UVLO level is set by the Not installed resistor-divider R1 and R2 resistor-divider between VIN and SGND 2-3 Connected to SGND Disabled *Default position. Table 2. MODE Selection Jumper (JU2) Settings SHUNT POSITION MODE/SYNC PIN MAX17632C OUTPUT 1-2 Connected to V DCM mode of operation CC 2-3* Connected to SGND PWM mode of operation Not installed OPEN PFM mode of operation *Default position. Maxim Integrated 2 www.maximintegrated.com