MAX20034 Evaluation Kit Evaluates: MAX20034 General Description Quick Start The MAX20034 evaluation kit (EV kit) is a fully assembled Required Equipment and tested application circuit that simplifies the evaluation MAX20034 EV kit of the MAX20034 high-efficiency 400kHz/2.2MHz, 36V, Adjustable DC power supply (PS1) dual buck controller IC. Two digital multimeters (DMM1 and DMM2) This EV kit operates from 3.5V to 42V supply and pro- vides two synchronous step-down outputs by switching Two electronic loads (EL1 and EL2) at 400kHz/2.2MHz, with each one 180 out of phase Procedure from the other. The frequency and output voltages can be The EV kit is fully assembled and tested. Follow the steps adjusted using external resistors. SYNC input program- below to verify board operation: mability enables three frequency modes for optimized performance: forced fixed-frequency operation, skip 1) Verify that all jumpers are in their default positions, as mode with ultra-low quiescent current, and synchronized shown in Table 1. external clock frequency. 2) Preset the power supply to 14V. Turn off the power supply. Benefits and Features 3) Preset the electronic loads to 2.5A. Turn off the Dual High-Voltage Step-Down Controllers to Minimize electronic loads. Board-Area Occupancy 4) Connect the positive lead of the power supply to the VBATTF PCB pad on the EV kit connect the negative Meets Stringent OEM Module Power Consumption lead to the neighboring PGND PCB pad. and Performance Specifications 5) Connect the positive terminal of electronic load EL1 17A Quiescent Current in Skip Mode to the VOUT1 PCB pad connect the negative lead to 1.5% Output-Voltage Accuracy: 5.0V/3.3V, Fixed or the PGND1 pad. Adjustable by External Resistor-Divider 6) Connect the positive terminal of electronic load EL2 to the VOUT2 PCB pad connect the negative lead to the EMI Reduction Features and Adjustable Fixed- PGND2 PCB pad. Frequency Operation to Reduce Signal Interference 7) Turn on the power supply. Optimized Application Layout and Components for 8) Verify that voltage across the VOUT1 and PGND1 Quick Design Implementation PCB pads is 5V, and 3.3V between the VOUT2 and Jumpers and Test Points on Key Nodes for Simplified PGND2 PCB pads. Evaluation 9) Turn on the electronic loads. 10) Verify that voltage across the VOUT1 and PGND PCB Proven PCB Layout pads is 5V 1.5%. Fully Assembled and Tested 11) Verify that voltage across the VOUT2 and PGND2 PCB pads is 3.3V 1.5%. 12) Turn off the electronic loads. Ordering Information appears at end of data sheet. 13) Turn off the power supply. 319-100105 Rev 0 11/17MAX20034 Evaluation Kit Evaluates: MAX20034 Table 1. Default Jumper Settings DEFAULT SHUNT JUMPER FUNCTION POSITION JU1 EN1 Pins 2-3 Enable for VOUT1 JU2 EN2 Pins 2-3 Enable for VOUT2 JU3 FSYNC Pins 2-3 Mode selection between skip enabled and FPWM JU4 PGOOD1 Installed Connect PGOOD1 to BIAS by pullup resistor JU5 PGOOD2 Installed Connect PGOOD2 to BIAS by pullup resistor JU6 EXTVCC Pins 1-2 Connect EXTVCC to VOUT1, VOUT2, or AGND Note: For 3-pin connectors, pin 1 is denoted by a silkscreen triangle. Buck Output Monitoring (PGOOD1, PGOOD2) Detailed Description The EV kit provides power-good output test points (TP The MAX20034 IC offers two high-voltage synchronous PGOOD1 and TP PGOOD2) to monitor the status of the step-down controllers that operate at 180 out-of-phase. buck outputs (VOUT1 and VOUT2). The PGOOD1 and This device can be powered up by an input voltage supply PGOOD2 are set to high impedance when the respective from 3.5V to 42V and can operate in drop-out condition by output voltages are in regulation. When the output voltages running at 99% duty-cycle. It is intended for applications individually drop below 92% of its nominal regulated volt- with mid- to high-power requirements that operate at a age, the corresponding PGOOD output is pulled to ground. wide input voltage range such as during automotive cold- crank or engine stop-start conditions. Setting the Output Voltage in The IC features a power-OK monitor, overvoltage lock- Buck Converters out, and an undervoltage lockout. Its protection features Each of the outputs has its own feedback pins (FB1 and include cycle-by-cycle current limit and thermal shutdown. FB2), which can be used to externally adjust the output It is specified for operation over the -40C to +125C auto- voltages between 1 to 10V. motive temperature range. For V , remove R1 and install a 0 resistor on R29. OUT1 Switching Frequency and Use the following equation to calculate the required value External Synchronization of the resistors for R2 and R3: The IC can operate in two modes: forced-PWM (FPWM) V OUT1 R2 R3 1 or skip. Skip mode has better efficiency for light-load con- V FB1 ditions, while FPWM has fixed switching frequency across all load conditions to prevent unwanted EMI interference. When SYNC is pulled low, the device operates in skip where V = 1V (typ) and recommended R6 = 50k. FB1 mode for light loads and in PWM mode for heavy loads. For VOUT2, remove R27 and install a 0 resistor on R31. When SYNC is pulled high, the device is forced to operate Use the following equation to calculate the required value in PWM across all load conditions. of the resistors for R25 and R26: SYNC pin can also be used to synchronize with an exter- nal clock frequency. In this case, MAX20034 operates at V OUT2 R25 R26 1 external clock frequency across all load conditions. V FB2 where V = 1V (typ) and recommended R6 = 50k. FB2 Maxim Integrated 2 www.maximintegrated.com = =