ADM00435: 1 LED @ 25 ~ 100mA, 0.5 ~ 5V in

The MCP1643 Synchronous Boost LED Constant Current Regulator Evaluation Board is used to evaluate and demonstrate Microchip Technology’s MCP1643 device. This board demonstrates the MCP1643 in a boost converter application supplied by one AA battery, or from an external voltage source, which drives an LED with four selectable currents. The MCP1643 Synchronous Boost LED Constant Current Regulator Evaluation Board was developed to help engineers reduce the product design cycle time.

Four output currents can be selected: 25, 50, 75 and 100mA. The output current can be changed with a dual switch that changes the external LED current sense equivalent resistance (for the position of the switches and output current see Table 2-1.)

An enable switch is used to enable and disable the converter. When enabled, the MCP1643 will regulate the output current; when disabled, the MCP1643 disconnects the path from input to output for “true-disconnect”. In this state, the current consumed from the battery is 1.2 μA, typically.