MCP1643 RGB LED DRIVER

DEMONSTRATION BOARD

USER’S GUIDE

 2016 Microchip Technology Inc.

DS50002437A-page 11

Chapter 1. Product Overview

1.1

INTRODUCTION

The MCP1643 is a compact, high-efficiency, fixed frequency, step-up DC-DC converter

optimized as an LED constant current generator. The device provides an easy-to-use

power supply solution, with a minimum number of external components for applications

powered by one-cell, two-cell Alkaline, NiCd or NiMH batteries.

This chapter provides an overview of the MCP1643 RGB LED Driver Demonstration

Board and covers the following topics:

• MCP1643 Device Overview

• MCP1643 Device Key Features

• MCP1643 RGB LED Driver Demonstration Board Overview

• MCP1643 RGB LED Driver Demonstration Board Features

• What the MCP1643 RGB LED Driver Demonstration Board Kit Includes

1.2

MCP1643 DEVICE OVERVIEW

The MCP1643 is a PWM-only device that operates at a fixed 1 MHz switching

frequency. The device has an operating input voltage range from 0.5V to 5V

For applications that require dimming, the LED can be turned on and off with a

variable duty cycle applied to the EN pin. The maximum dimming frequency is only

limited by the internal soft-start of 240 μs. The device is available in 8-lead MSOP and

8-lead 2x3 mm DFN packages.

1.3

MCP1643 DEVICE KEY FEATURES

• 1.8A typical peak input current limit

• Up to 550 mA LED load current

• Low operating input voltage: down to 0.5V

• Maximum input voltage <V

• Maximum output voltage: 5V

• Overvoltage protection (5V)

• Low reference voltage:

- Minimal power loss on sense resistor

• Pulse-Width Modulation mode operation (1 MHz)

• Internal synchronous rectifier

• Internal compensation

• Inrush current limiting

• Internal soft start (240 μs typical)

• Shutdown (EN=GND):

- True load disconnect

- Dimming control by variable duty cycle