MCP1643 RGB LED Driver Demonstration Board User’s Guide

DS50002437A-page 16

 2016 Microchip Technology Inc.

2.2

GETTING STARTED

The MCP1643 RGB LED Driver Demonstration Board is fully assembled and tested to

evaluate and demonstrate the MCP1643 product operating with an external PWM

signal. This board requires the use of an external power supply or a AA battery.

The package selected for the MCP1643 is the MSOP-8.

2.2.1

Powering the MCP1643 RGB LED Driver Demonstration Board

Soldered test points are available for input voltage connections. The maximum input

voltage should not exceed 2V due to the forward voltage of the LED’s red color of 2.1V.

The forward voltage for the blue and green colors is 3.5V.

After connecting an external power supply or an AA battery, the board enters the

Shutdown mode and only consumes 1.2 µA of current. To start the board, press the

Start

push-button. The second push-button has two functions: a short press shuts

down the board, while a long press of more then 0.5 sec puts the board in a temporal

demonstration state.

2.3

BOARD TESTING

Follow these steps to test the board functionalities:

battery slot on the back of the board. Please observe the polarity to avoid board

damage.

2. Press the Start push-button to enable the converter. The board will run a start-up

demonstration program with all colors at low brightness, after which the user will

be able to control the brightness. It is recommended to avoid looking directly into

the LED, to prevent eye damage.

3. Change each color brightness by using the three potentiometers marked Red,

Green and Blue, corresponding to each color of the RGB LED.

4. To run the demonstration program, press the Stop/Demo push-button for 0.5s.

5. To stop the MCP1643 RGB LED Driver Demonstration Board, short-press the

Stop/Demo

button.

6. Additional test points are available to visualize different signals (FB, output

current, EN, SW).

FIGURE 2-3:

MCP1643 RGB LED Driver Demonstration Board Power Supplies.

A 0Ω (R7) resistor is used for bench testing. By removing R7, the soldered test points

can be used to create a wire loop and visualize the current through the LED by using

an oscilloscope current probe.

Power supply

+

-