Design Of A Fiber Optic LED Driver Chip

Fiber optic LED and Fiber optic LED driver become the important parts of the optical fiber communications, for the use of them is very cheap and conveniency.It's features of power and precision will directly attract the capability of optical fiber equipment.So it is worth to design a LED driver with the features of low power agility and higher precision. This paper presents a practical design of a fiber optic LED driver. The chip suited for network applications up to 20Mbps. The part is capable of driving up to 100mA of current through a Fiber Optic LED from an ECL or TTL level input signal. The LED driver's output stage provides fast, well matched rise and fall times through a unique class-B output stage that bums supply current only when the LED is on. A positive temperature coefficient of up to 3300ppm/℃can be programmed into the output current to compensate for the negative temperature coefficient to the LED optical output power. An peaking circuit may also be employed to compensate for output current's overshoot and undershoot. The chip use BeiLing 2 μm Bipolar process. The results of circuit simulation, the functions of this chip meet the design goals entirely with many good performances.