Littelfuse, Inc.
CURRENT CORRECTION TECHNIQUES FOR ACCURATE HIGH CURRENT SHORT CHANNEL DRIVER

Abstract:

A current driver integrated circuit (IC) is coupled to control current flow through a diode. In one example, the diode is a Light Emitting Diode (LED) having an anode coupled to a supply node supplied by a battery and a cathode coupled to a drive terminal of the current driver IC. During operation the current driver IC is enabled and sinks an output current from the supply node, through the LED, through the drive terminal, and onto a ground node. As current flows through the LED, the battery is discharged. Changes in battery voltage cause an output voltage between the cathode of the LED and the ground node to change. Despite variations in output voltage, the current driver IC maintains a current level of the output current to be within five percent of a desired output current level across an output voltage range of at least 2V.