Click here for production status of specific part numbers. Evaluates: MAX20079 MAX20079 Evaluation Kit General Description Quick Start The MAX20079 evaluation kit (EV kit) provides a proven Required Equipment design to evaluate the MAX20079 2.1MHz/400kHz high- MAX20079 EV kit voltage mini-buck converter in a 20-pin Side-Wettable Power Supply TQFN (SWTQFN) package. All components are rated for the automotive temperature range. Various test points Voltmeter and jumpers are included for evaluation. Electronic Load MAX20079EVKIT comes with MAX20079AATP/VY+ Procedure installed (5V, 2.1MHz) and can be used to evaluate any The EV kit is fully assembled and tested. Follow the steps MAX20079 variant with minimal component changes. below to verify board operation: Benefits and Features 1) Verify that all jumpers are in their default positions, as 3.5V to 36V Input Supply Range shown in Table 1. 5V or 3.3V Fixed Output Voltage, or Adjustable 2) Connect the positive and negative terminals of Between 3V and 10V the power supply to the SUP and GND test pads, respectively. Delivers Up to 3.5A Output Current 3) Connect the positive terminal of the voltmeter to OUT, Frequency Synchronization Input and the negative terminal to GND2 Enable Input 4) Set the power supply to 14V and 3A current limit. Turn Voltage-Monitoring PGOOD Output on the power supply. Proven PCB Layout 5) The voltmeter should display an output voltage of 5V. Fully Assembled and Tested 6) Connect an electronic load to OUT and GND2 termi- nals and set it to 1A. Ordering Information appears at end of data sheet. 7) Turn ON the electronic load and increase the cur- rent to 3.5A. The voltmeter should display the output voltage of 5V 2%. Table 1. Default Jumper Settings SHUNT JUMPER FUNCTION POSITION EN Middle-ON Buck controller enabled SPS Middle-OFF Spread spectrum disabled PGOOD is pulled up by J1 Installed VBIAS when OUT is in regulation FSYNC Middle-FPWM Forced-PWM mode 319-100273 Rev 0 10/18Evaluates: MAX20079 MAX20079 Evaluation Kit To obtain a logic signal, pull up PGOOD to V by BIAS Detailed Description installing shunts on jumper PU. The MAX20079 EV kit provides a proven layout for all variants of the MAX20079 synchronous buck regulator. Evaluating Other Variants The device accepts input voltages as high as 36V and The EV kit comes installed with the fixed-output, delivers up to 3.5A. The EV kit can handle an input-supply 5V/2.1MHz variant (MAX20079AATP/VY+). The transient up to 40V. 3.3V/2.1MHz and 400kHz variants (MAX20079BATP/ VY+, MAX20079DATP/VY+, and MAX20079EATP/VY+) Switching Frequency/ can be installed with minimal component changes. For External Synchronization the 3.3V/2.1MHz variant, install the MAX20079AATP/VY+ The devices can operate in two modes: forced-PWM or on the EV kit (U1), while keeping all other components the Skip. Skip mode has better efficiency for light-load condi- same. For 400kHz parts, a 10H inductor and an effective tions. When SYNC is pulled low, the device operates in output capacitance of 44F is recommended after derat- skip mode for light loads and in PWM mode for larger ing is accounted for. loads. When SYNC is pulled high, the device is forced to operate in PWM across all load conditions. Setting the Output Voltage in Buck Converters SYNC can be used to synchronize with other supplies if a clock source is present. The device is forced to operate in To externally adjust the output voltage, remove R6 and PWM when SYNC is connected to a clock source. install a 0 resistor on R3. Place appropriate resistors in positions R4 and R5 according to the following equation: Buck Output Monitoring (PGOOD) The EV kits provide a power-good output test point V OUT1 R4 R5 1 (PGOOD) to monitor the status of the buck output (OUT). V FB PGOOD is low impedance when the output voltage is in regulation. PGOOD is high impedance when the output where V = 1V (typ) and R5 = 50k. FB voltage drops below 8% (typ) of its nominal regulated voltage. Ordering Information PART TYPE MAX20079EVKIT 5V output, 2.1MHz EV kit Denotes RoHS Compliant Maxim Integrated 2 www.maximintegrated.com =