MAX25610EVKIT# Analog Devices

Click here for production status of specific part numbers. Evaluates: MAX25610A MAX25610 Evaluation Kit General Description Quick Start The MAX25610 evaluation kit (EV kit) provides a proven Required Equipment design to evaluate the MAX25610A automotive high-volt- MAX25610 EV kit age, high-brightness LED (HB LED) controller. The EV kit 12V, 5A DC power supply is set up for buck-boost configurations and operates from a 5V to 18V DC supply voltage. The EV kit is configured A series-connected LED string rated for at least 1.5A to deliver up to 1.1A to one string of LEDs. The total volt- Oscilloscope with a current probe age of the string can vary from 3V to 16V. The anode of the LED string should go to the LED+ terminal and the Procedure cathode should go to the LEDEXT- terminal. The EV kit is fully assembled and tested. Follow the steps below to verify board operation: Benefits and Features Caution: Do not turn on power supply until all con- 5V to 18V Input Voltage Range nections are made. Demonstrates Analog Dimming Control, Digital 1) Verify that all jumpers are in their default positions, Dimming Control as shown in Table 1. Demonstrates External and Internal Current Sensing 2) Connect the positive terminal of the 12V supply to Demonstrates LED Short and Open Protection the V Board PCB pad and the negative terminal to IN Proven PCB Layout the GND Board PCB pad. Fully Assembled and Tested 3) Connect the LED string across the LED+ and LE- DEXT- PCB pads on the EV kit. The anode of the LED string should go to the LED+ PCB pad and the cathode of the LED string should go to the LEDEXT- Ordering Information appears at end of data sheet. PCB pad. 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 illuminate. 7) Verify that the oscilloscope displays approximately 1A. 319-100359 Rev 0 4/19Evaluates: MAX25610A MAX25610 Evaluation Kit PWM Dimming Detailed Description The EV kit demonstrates the PWM dimming feature of the The MAX25610 evaluation kit (EV kit) provides a proven MAX25610A using either an external PWM signal or a DC design to evaluate the MAX25610A automotive high-volt- voltage at the PWMDIM pin. age, high-brightness LED (HB LED) controller. The EV kit is set up for buck-boost configurations and operates from Analog-to-PWM dimming: a 5V to 18V DC supply voltage. The EV kit is configured Keep J2 open and J7 closed as described in Table 1 and to deliver up to 1.1A to one string of LEDs. The total volt- remove the 0.1F C8 capacitor. PWM dimming duty cycle age of the string can vary from 3V to 16V. The anode of is set by the voltage at PWMDIM between 0.2V (0% duty) the LED string should go to the LED+ terminal and the and 3V (100% duty). Alternatively, drive the PWMDIM cathode should go to the LEDEXT- terminal. test point with an external DC source. PWMDIM voltages greater than 3V set the dimming duty cycle to 100%. Analog Dimming Control (REFI) When J1 is closed, the LED current is set by external External PWM dimming: current sensing. The equation to set the LED current is Keep J2 open and J7 open. Install the 0.1F C8 capacitor as follows: (installed by default). Connect an external PWM signal to V - 200mV REFI the PWMDIM test point. Vary the duty cycle to increase I = LED 6.67 R or decrease the intensity of the HB LED string. The LED PWMDIM input of the device has a 2V (max) rising thresh- old and a 0.4V (min) falling threshold, and is compatible In the case of the EV kit, ILED is set to 1A. with 3.3V and 5V logic-level signals. When J1 is open, the LED current is set by internal cur- rent sensing. The equation to set the LED current is I LED = 13125/R . REFI Table 1. MAX25610 EV Kit Jumper Descriptions JUMPER SHUNT POSITION DESCRIPTION For external current sense. The voltage on the REFI pin is adjusted from 0.2V to 1.2V to set Closed* the LED current as follows: I = (V 0.2)/6.67 x R LED REFI LED J1 For internal current sense. The potentiometer R23 is adjusted for setting the LED current as Open follows: I = 13125/R LED REFI 12 Connects PWMDIM pin to GND and no switching J2 23* Connects PWMDIM pin to V (Internal 5V) for 100% duty EE Connect an external clock source to perform PWM dimming with J7 open. With J7 closed, the potentiometer R34 is adjusted to set the DC voltage on the PWMDIM Open pin to perform analog PWM dimming. The capacitor C8 must be removed to perform analog PWM dimming. J4 See the IC datasheet for PWM frequency setting. 12* External current sense 23 Internal current sense Open* For external PWM dimming J7 Closed For analog PWM dimming Maxim Integrated 2 www.maximintegrated.com