Click here for production status of specific part numbers. MAX25601 Evaluation Kit Evaluates: MAX25601A General Description Quick Start The MAX25601 evaluation kit (EV kit) provides a proven Required Equipment design to evaluate the MAX25601A automotive high-volt- MAX25601 EV kit age, high-brightness LED (HB LED) boost-buck controller. 12V, 5A DC power supply The front-end pre-boost operates from a 7.7V to 18V DC supply voltage, generating a 48V output. The buck sup- A series-connected LED string rated at least 1.5A ports 12x LEDs and lower, delivering up to 1.5A to one Oscilloscope with a current probe string of LEDs. The total voltage of the string can vary from 3V to 36V. Procedure The EV kit is fully assembled and tested. Follow the steps Benefits and Features below to verify board operation. Caution: Do not turn on Configured for Pre-Boost and Buck Application power supply until all connections are made. Analog Dimming Control 1) Verify that all jumpers are in their default positions, as shown in Table 1. Proven PCB Layout 2) Connect the positive terminal of the 12V supply to Fully Assembled and Tested the IN PCB pad and the negative terminal to the nearest GND PCB pad. 3) Connect the LED string across the LED+ and the nearest GND PCB pad. Ordering Information appears at end of data sheet. 4) Clip the current probe on the wire connected to the LED string. 5) Turn on the DC power supply. 6) Verify that the LEDs turn on. 7) Verify that the oscilloscope displays approximately 1A. 8) Monitor desired signals on headers J6 and J7. 319-100461 Rev 0 10/19MAX25601 Evaluation Kit Evaluates: MAX25601A is a 10k potentiometer, with the wiper shorted to the high Detailed Description of Hardware side of the potentiometer. Install the shunt on J2(2-3) (see The MAX25601 evaluation kit (EV kit) provides a proven Table 1 for jumper descriptions). Using a flat-blade screw- design to evaluate the MAX25601A automotive high-volt- driver, turn the wiper-adjustment pin clockwise to increase age, high-brightness LED (HB LED) boost-buck controller. the voltage on the REFI input. Turn the wiper-adjustment The front-end pre-boost operates from a 7.7V to 18V DC pin counterclockwise to decrease the voltage on the REFI supply voltage, generating a 48V output. The buck sup- input. The REFI input allows for analog dimming of the ports 12x LEDs and lower, delivering up to 1.5A to one HB LED string. A REFI input voltage of 0.2V turns off string of LEDs. The total voltage of the string can vary the LED driver, an input voltage between 0.2V and 1.2V from 3V to 36V. provides linear dimming of the HB LED string, and an The combination of the number of LEDs and buck switch- input voltage > 1.2V sets the HB LED string current to ing frequency determine the required input voltage for the maximum current (based on the current-sense resistor). buck, which is the output voltage of the boost. The boost Alternatively, the analog dimming input can be set with a regulator supports a maximum of around 50W of output power supply. Remove the shunt on J1 and connect an power, or ~10A when operating down to 6V input. external power supply directly to the REFI pin J7 pin 3 Analog Dimming Control (REFI) to perform analog dimming with a power supply. Do not violate the absolute maximum voltage rating of VCC+0.3V The EV kit demonstrates the analog dimming feature of (refer to the Absolute Maximum Ratings section in the the buck controller. R1 and R2 form a resistor-divider MAX25601 IC data sheet). between VCC and AGND. R1 is a 24.9k resistor and R2 Table 1. MAX25601 EV Kit Jumper Descriptions JUMPER SHUNT POSITION DESCRIPTION Connects DIM to a voltage-divider from VCC to ground. When DIM is above 3V, the buck regulator is fully on at 100% dim duty cycle. 1-2* When DIM is between 0.2V and 3V, the buck regulator operates at a duty cycle proportional to the DIM voltage, at a frequency of 200Hz. J1 When DIM is below 0.2V, the buck regulator is disabled. 2-3 Connects the DIM pin to ground to disable the buck regulator. Disconnects DIM from the voltage divider. Allows DIM to be driven by an external Open voltage source or PWM signal to drive the DIM pin. Connects VCC to the REFI pin. LED current is at the maximum value of 1.5A in this 1-2 configuration. Connects REFI to a voltage-divider from VCC to ground. Adjusting R2 allows J2 2-3* programming the LED current from 0 to 1.5A. Disconnects the REFI pin of the device from the external voltage-divider on the VCC Open pin. Allows REFI to be driven by an external voltage to set the LED current level. J6 Open* FLTB, RT/SYNCIN and PWM HUD signals can be accessed. J7 Open* PWMDIM, IOUTV, REFI and HUD OUT signals can be accessed. 1-2 HUD dimming jumper J9 Open* Disconnects HUD dimming *Default position. Maxim Integrated 2 www.maximintegrated.com