GD16578

The GD16578 is a high performance low power 2.5 Gbit/s Laser Driver with optional on chip retiming of data.The GD16578 is designed to meet and exceed ITU-T STM-16 or SONET OC-48 fiberoptic communication systems requirements.The GD16578 is designed to sink a modulation current into the IOUT pin and a pre-bias current into the IPRE pin.The modulation current is adjustable up to 200 mA by means of the pin VMOD.The pre-bias current may be adjusted up to 60 mA by means of the VPRE pin.

Features of the GD16578 are:(1)complies with ITU-T STM-16 and SONET OC-48 standards; (2)intended for driving a 25load, e.g.a laser diode or mach zender modulator with 25 input impedance; (3)clocked or non-clocked operation; (4)large modulation current adjustment range from 70 mA to 200 mA; (5)output voltage over / under shoot less than ±5 % respectively ±10 %; (6)rise / fall times less than 100 ps; (7)laser diode pre-bias adjustable up to 60 ma; (8)mark-space monitor; (9)symmetry adjustment; (10)internal 50 termination of data and clock inputs; (11)power dissipation: 1 W (typ.).(excluding Modulation Current and Pre-bias Current); (12)32 pin thermally enhanced TQFP plastic package.

The absolute maximum ratings of the GD16578 can be summarized as:(1)power voltage:-6 to 0V;(2)storage temperature:-40 to +110;(3)operating temperature:-65 to +125 ;(4)applied voltage(all output):Vee-0.5 to 0.5V;(5)input current(AC in):-1 to 1 mW.The output modulation current is controlled by the pin VMOD and can be controlled in the range from 0 mA to 200 mA,however the specifications is only valid in the range from 70 mA to 200 mA.The output voltage swing across the external load may be varied accordingly. The modulation current control on pin VMOD is implemented as a current mirror and therefore sinks a current proportional to the modulation current.The current sink into the VMOD pin is approximately 1/210 of the modulation current.