High Performance LED Driver
Original Publication Date: 1984-May-01
Included in the Prior Art Database: 2005-Feb-03
A light-emitting diode (LED) driver circuit is described which provides improved current switching rise and fall times and does not require the use of precision load resistors. It operates from a low voltage (e.g., +5-volt) source and has a high degree of insensitivity to power supply and temperature variations. This circuit uses an N-channel power vertical metal oxide semiconductor field-effect transistor (MOSFET) 1 as the driving transistor for the LED 2 and takes advantage of the unique characteristics of this MOSFET device. This MOSFET 1 exhibits a high gate (G) input impedance, produces a current proportional to its input voltage, is extremely linear, and produces high-current nanosecond switching speeds.