MCP1633 SEPIC
LED DRIVER
DEMONSTRATION BOARD
USER’S GUIDE
2020 Microchip Technology Inc.
DS50002945A-page 9
Chapter 1. Product Overview
1.1
INTRODUCTION
The MCP1633 SEPIC LED Driver Demonstration Board is a step-up/step-down, Switch
mode, DC/DC converter used for LED driver applications. The MCP1633 SEPIC LED
Driver Demonstration Board provides a 200 mA constant-current source. Other output
current options can be obtained with minimum modifications to the board’s Bill of
Materials. The MCP1633 SEPIC LED Driver Demonstration Board utilizes the
MCP1633 high-speed Pulse-Width Modulator (PWM). The small MCP1633 16-pin
QFN device contains all the analog components necessary for a Peak Current mode
control loop, including specialized LED driver blocks. An 8-pin PIC12F1822
microcontroller is used to implement the dimming and protection functions.
1.2
BOARD FEATURES
The MCP1633 SEPIC LED Driver Demonstration Board has the following features:
• Compact size with high output power
• Operates in Buck mode (step down) or Boost mode (step up)
• Sustains voltage stresses (typically found in automotive products): 42V in for
180 ms
• High efficiency over entire operating input and output voltage ranges: 85% (typical)
• Typical output current: 200 mA (can be adjusted via hardware)
• Factory programmed source code provider
• Additional application functions can be implemented in the firmware
1.3
DEVICE SUMMARY
The MCP1633 SEPIC LED Driver Demonstration Board uses the following primary
devices on the board:
• MCP1633 High-Speed PWM Controller: When used in conjunction with the
microcontroller, the MCP1633 device controls the power system duty cycle in
order to provide output current and/or voltage regulation.
• PIC12F1822 Microcontroller (8-bit MCU): Used to implement the dimming
function, manage the Faults and protect the on-board load from overheating.
• MCP1790 Low-Dropout (LDO) Regulator: Used to supply regulated voltage (+5V)
to the PIC12F1822 microcontroller, the MCP1633 PWM controller and the
MCP9700 temperature sensor. The MCP1790 device can deliver 70 mA and
s48V on input for 180 ms (30-second repetition rate).
• MCP9700 Low-Power Voltage Output Temperature Sensor: Used to measure the
LED temperature.
