Ultra high speed laser driver circuit with bandwidth compensation and driver chip

Abstract

The invention discloses an ultra high speed laser driver circuit with bandwidth compensation and a diver chip; the feedback circuit composed of two cross coupling capacitors and the capacitor and the resistor connected in a parallel mode is used for executing the laser driver bandwidth compensation. For two cross coupling capacitors, the stray capacitance between the base and the collector can be eliminated; for the feedback mode of one capacitor and one resistor, one zero point is generated for compensating the pole for realizing the bandwidth compensation; and the modulating current directly flows to the laser diode through the load resistor, so that the laser diode can obtain larger modulating current. The laser driver circuit and the driver chip having pre-emphasis function are simple in structure, high in bandwidth, large in modulating current and low in power consumption; the chip adopts the resistor and capacitor for expanding the bandwidth, the occupied area is small and the chip cost is reduced; the work speed is 40Gb / s through the 0.13 mum BiCMOS process certification and the output modulating current is greater than 10 mA.

Description

technical field [0001] The invention relates to a laser driver circuit at a transmitting end in an optical fiber communication system, in particular to a bandwidth-compensated ultra-high-speed laser driver circuit and a driver chip. Background technique [0002] Due to its large capacity and other characteristics, the optical fiber communication system has developed rapidly in network and multimedia communication. At the front end of the optical fiber is the light emitting end, which is composed of a multiplexer, a laser driver and a laser diode. The role of the optical transmitter is to multiplex multiple low-speed data signals into one high-speed signal through the multiplexer. After being amplified by the laser driver circuit, the laser diode is driven to emit light, converted into a high-speed optical signal, and transmitted through the optical fiber. Therefore, the design goal of the laser driver is to obtain high bandwidth and large output modulation swing performance...

AI Technical Summary

Problems solved by technology

Therefore, the design goal of the laser driver is to obtain high bandwidth and large output modulation swing performance. Most of the existing laser driver circuits with pre-emphasis function use inductive elements to expand the bandwidth, and the structure is relatively complex and requires a large amount of chip area. Increased cost of chip manufacturing

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