Temperature compensation circuit for direct modulation laser driver

Abstract

The invention discloses a temperature compensation circuit for a direct modulation laser driver, which determines the temperature compensation based on the current real-time temperature of the laser and the initial operating temperature of the laser. The temperature compensation circuit for a direct modulation laser driver comprises a ring oscillator, a frequency-to-digital converter, a slope setting module, a power control unit and a digital-to-analog converter, wherein the output end of the ring oscillator is connected with the input end of the frequency-to-digital converter; the output endof the frequency-to-digital converter and the output end of the slope setting module are both connected with the input end of the power control unit; the output end of the power control unit is connected with the input end of the digital-to-analog converter; and the output end of the digital-to-analog converter is connected with a current output module of the laser driver. The temperature compensation circuit of the invention determines the temperature compensation based on the current real-time temperature of the laser and the initial operating temperature of the laser, which can improve theaccuracy and precision of the temperature compensation, and flexibly and conveniently performs temperature compensation on the bias current and the modulation current of the direct-adjusting laser driver as well as reduces the complexity and occupied area of circuit design.

Description

technical field [0001] The invention relates to a temperature compensation circuit, in particular to a temperature compensation circuit for a direct modulation laser driver. Background technique [0002] In optical communication systems, laser drivers and laser diodes are important components of optical transmitters. The functions of the laser driver mainly include: (1) convert the input data voltage signal into a modulated current signal, and drive the laser diode; (2) provide a bias current for the laser diode, so that the laser diode works near the threshold current. [0003] Because laser diodes are sensitive to temperature, their output optical power varies greatly with temperature. Such as figure 1 As shown, when the laser diode works under different temperature conditions, the electro-optical conversion efficiency and threshold current of the laser diode will change. As the temperature increases, the electro-optical conversion efficiency of the laser diode decrease...

AI Technical Summary

Problems solved by technology

Most current temperature compensation circuits lack flexibility and provide a small range of temperature compensation coefficients, resulting in poor adaptability of temperature compensation circuits

In addition, the existing on-chip temperature compensation circuits are usually realized by analog circuits, which require operational amplifiers, bandgap reference circuits and other circuits, and the circuit design is relatively complicated and occupies a large area

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