Evaluates: MAX17231, MAX17230 MAX17231 Evaluation Kit General Description Quick Start The MAX17231 evaluation kit (EV kit) is a fully assembled Recommended Equipment and tested application circuit board for the MAX17231 MAX17231 EV Kit high-voltage, dual synchronous step-down controller with 3.5V to 36V, 20A power supply (the power supply preboost. The EV kit is set up to provide 5V and 3.3V from should be capable of providing 20A at 3V input) an input voltage ranging from 3.5V to 36V. The preboost Two voltmeters circuit maintains the 10V supply rail for input voltages Two electronic loads capable of sinking 5A each below 10V. Each buck rail can deliver up to 5A load current. Various jumpers are provided to help evaluate features of Procedure the MAX17231 IC. The EV kit is fully assembled and tested. Follow the steps below to activate the board. Caution: Do not turn on the Features power supply until all connections are completed. Dual, Synchronous Step-Down Controllers Operate 1) Verify that all jumpers are in their default configurations at 180 Out-of-Phase to Reduce Switching Noise according to Table 1. Preboost Controller to Maintain Operation with Low 2) Connect the positive and negative terminals of the Supply Voltage power supply to the VBATF and PGND banana jacks, 3.5V to 36V Wide Input Supply Range respectively. Buck Output Voltage: 5V and 3.3V Fixed or 3) Connect the positive terminal of the first electronic load to Adjustable Between 1V and 10V the VOUT1 banana jack. Connect the ground terminal Current-Mode Controllers with Forced-PWM and Skip of the electronic load to the corresponding PGND Modes banana jack. Resistor-Configurable Frequency Between 1MHz and 4) Connect the positive terminal of the second electronic 2.2MHz load to the VOUT2 banana jack. Connect the ground terminal of the electronic load to the corresponding Independent Enable Inputs PGND banana jack. 85% Peak Efficiency at 12V Input in Skip-Mode 5) Set the power-supply voltage to 14V. FSYNC Input and Power-Good Output 6) Turn on the power supply. Proven 4-Layer 2oz Copper PCB Layout 7) Enable the electronic loads. Demonstrates 1937mil x 1702mil Solution Size 8) Verify that VOUT1 is approximately 5V. Fully Assembled and Tested 9) Verify that VOUT2 is approximately 3.3V. EV Kit Contents MAX17231EV Kit Board Ordering Information appears at end of data sheet. 19-8624 Rev 0 5/17Evaluates: MAX17231, MAX17230 MAX17231 Evaluation Kit Table 1. Default Jumper Settings JUMPER DEFAULT SHUNT POSITION FUNCTION JU1, JU2 Installed PGOOD pulls up to BIAS when OUT is in regulation. JU3 Installed Preboost on-indicator enabled. JU5 1-4 Switches to EXTVCC. Internal regulator disabled. JU6 1-2 Forced-PWM mode. JU7, JU8, JU9 1-2 Buck outputs, preboost enabled. Detailed Description of Hardware Table 2. EXTVCC (JU5) The MAX17231 EV kit, which evaluates the MAX17231 SHUNT EXTVCC BIAS high-voltage, dual synchronous step-down controller with POSITION PIN preboost, can supply up to two rails. The EV kit includes Switches to EXTVCC. two current-mode buck outputs that are fixed to 5V Connected to 1-2 Internal regulator and 3.3V, or configurable from 1V to 10V with external VOUT2 disabled. resistor-dividers. The current capability is 5A per rail. Both outputs are current limited and can be controlled Internal regulator Connected to independently through their respective enable inputs 1-3 enabled to generate PGND EN . The EV kit includes an external preboost, which BIAS supply. enables full output functionality during undervoltage Switches to EXTVCC. Connected to events. The EV kit also includes a 5V, 100mA internal 1-4* Internal regulator VOUT1 linear regulator (BIAS), which powers the internal circuitry disabled. of the MAX16930. *Default configuration. Switching Frequency/External Synchronization Table 3. Mode of Operation (JU6) The EV kit switching frequency can be adjusted from 1MHz to 2.2MHz by changing the F resistor R75. OSC SHUNT FSYNC MODE The EV kit can also be synchronized to an external clock POSITION PIN by connecting the external clock signal to the FSYNC 1-2* Connected to BIAS Forced-PWM mode test point and AGND. Refer to the Switching Frequency/ 2-3 Connected to AGND Skip mode External Synchronization section in the MAX17231 IC data sheet for more details. *Default configuration. Buck Output Monitoring (PGOOD ) EXTVCC Switchover Comparator The EV kit provides two power-good output test points The internal linear regulator can be bypassed by connecting (PGOOD1 and PGOOD2) to monitor the status of the two an external supply (3V to 5.2V) or the output of one of buck outputs (OUT1 and OUT2). Each PGOOD goes the buck converters to EXTVCC. BIAS internally switches high (high impedance) when the corresponding regulator to EXTVCC and the internal linear regulator turns off. If output voltage is in regulation. Each PGOOD goes low V drops below V = 3V(min), the internal EXTVCC TH,EXTVCC when the corresponding regula tor output voltage drops regulator enables and switches back to BIAS. below 15% (typ) or rises above 10% (typ) of its nominal Mode of Operation regulated voltage. The EV kit features jumper JU6 to configure the mode To obtain a logic signal, pull up PGOOD to BIAS by switch-control input. Drive FSYNC high (pins 1-2 of JU6) installing shunts on JU1 and JU2. to enable forced-PWM mode. Drive FSYNC low (pins 2-3 of JU6) to enable skip mode under light loads. Maxim Integrated 2 www.maximintegrated.com