 2015 Microchip Technology Inc.

DS50002363A-page 13

MCP1664 LED DRIVER

EVALUATION BOARD

USER’S GUIDE

Chapter 2. Installation and Operation

2.1

INTRODUCTION

The MCP1664 has been developed for applications that require driving a string of

LEDs from a low-voltage source. The MCP1664 is a non-synchronous step-up

regulator that can operate over a wide output range up to 32V. Its maximum output

current is based on the switch peak current limit (set to 1.8A) and on the maximum

duty cycle of 90%. An important feature is that the device integrates the compensation

and protection circuitry so that the final solution will require a minimum number of

additional components.

FIGURE 2-1:

MCP1664 LED Driver Boost Converter 90,180,270 mA Constant Current Application.

2.2

FEATURES

The MCP1664 LED Driver Evaluation Board has the following features:

• Undervoltage lockout: 2.3V to start; 1.85V to stop

• Adjustable output current: 90 mA, 180 mA or 270 mA, selected using a mini dip

switch on board

• PWM Switching frequency = 500 kHz

• Variable resistor and triangular wave generator on the board that can be used for

PWM dimming

• 1.8A peak current limit

• Overtemperature protection (if the die temperature exceeds +150°C, 25°C hysteresis)

• Open load protection: if the LED string fails or is disconnected, the converter will

shut down to prevent failure.

PWM Dimming

GND

SW

EN

2 x 10 µF

4.7 µH

3.3



3.3



3.3



2.4V - 5.5V

Note 1: For PWM Dimming Block refer to Figure 2-4.

MBRA140

0



10 µF

MCP1664