MAX25600EVKIT# Analog Devices

Click here for production status of specific part numbers. Evaluates: MAX25600 MAX25600 Evaluation Kit General Description Quick Start The MAX25600 evaluation kit (EV kit) provides a reliable Required Equipment platform for validating designs that use the MAX25600 MAX25600 EV kit automotive high-voltage, high-brightness LED (HB LED) 12V, 5A DC power supply buck boost controller. The EV kit operates from 8V to 48V DC supply voltage. The EV kit is configured to deliver up A series-connected LED string rated at least 1.5A to 1.5A to one string of one to fifteen LEDs. The total volt - Oscilloscope with a current probe age of the string can vary from 3V to 60V. Procedure Benefits and Features The EV kit is fully assembled and tested. Follow the steps 8V to 48V Input Voltage Range below to verify board operation: Demonstrates Analog Dimming Control, Digital Caution: Do not turn on the power supply until all Dimming Control connections are made. Demonstrates Input Current Limit 1) Verify that all jumpers are in their default positions, as shown in Table 1. Demonstrates LED Current Monitoring function 2) Connect the positive terminal of the 12V supply to Demonstrates LED Short and Open Protection the VINP1 board PCB pad and the negative terminal Proven PCB Layout to the GND1 board PCB pad. 3) Connect the LED string across the LED+ and LED- Fully Assembled and Tested PCB pads on the EV kit. The Anode of the LED string should go to the LED+ PCB pad and Cathode of the LED string to LED- PCB pad. 4) Clip the current probe on the wire connected to the LED string. 5) Turn on the DC power supply. Ordering Information appears at end of data sheet. 6) Verify that the LEDs turn on. 7) Verify that the oscilloscope displays approximately 1.5A. 319-100380 Rev 0 5/19Evaluates: MAX25600 MAX25600 Evaluation Kit PWM Dimming Detailed Description The EV kit demonstrates the PWM dimming feature of the The MAX25600 evaluation kit (EV kit) provides a reliable MAX25600 using either an external PWM signal, or a DC platform for validating designs that use the MAX25600 voltage at the PWMDIM pin. automotive high-voltage, high-brightness LED (HB LED) buck boost controller. The EV kit operates from 8V to 48V External PWM dimming: DC supply voltage. The EV kit is configured to deliver up Keep J4 open and remove the 0.1uF C55 capacitor to 1.5A to one string of LEDs. The total voltage of the (installed by default). Connect an external PWM signal to string can vary from 3V to 60V. the PWMDIM test point. Vary the duty cycle to increase or decrease the intensity of the HB LED string. The Analog Dimming Control (ICTRL) PWMDIM input of the device has a 2V (max) rising thresh- When J2 is closed, the LED current is set by the resistive old and a 0.4V (min) falling threshold and is compatible divider from VCC. The equation to set the LED current is with 3.3V and 5V logic-level signals. V 200mV ICTRL Analog-to-PWM dimming: I = LED 5 R9 Keep J4 open and keep the 0.1uF C55 (installed by default). The PWM dimming duty cycle is set by the volt- In the case of the EV kit, ILED is set to 1.5A. Use a screw age at PWMDIM between 0.2V (0% duty) and 3.2V (100% driver on the potentiometer R21 to adjust the LED current. duty). Drive the PWMDIM test point with an external DC source. PWMDIM voltages above 3.2V set the dimming duty cycle to 100%. Table 1. MAX25600 EV Kit Jumper Descriptions JUMPE SHUNT POSITION DESCRIPTION R Closed Short the PMOS PWM dimming switch. J1 Open* PWM dimming done with the PMOS switch Closed Uses the resistive divider from VCC and the potentiometer R21 to set the LED current. J2 Open Apply an external DC voltage between 0.2V to 1.2V for setting LED current. Open Connect an external power supply for the IN pin of the IC, using the IN IC PAD. 1-2* Connect the IN input of the IC to the VIN power supply connected on VINP1 PAD. J3 The IN and VCC inputs of the IC are shorted and should be driven with an external 5V 2-3 supply. Apply an external PWM clock source for PWM dimming or apply an external DC source Open between 0.2V to 3.2V for analog PWM dimming. J4 1-2* PWMDIM pin pulled to VCC for 100% duty. 2-3 PWMDIM pin pulled to GND to turn OFF. Maxim Integrated 2 www.maximintegrated.com