Adaptive sampling qualification for extinction ratio control

摘要

Techniques are described for adaptive sampling qualification for extinction ration control. The techniques may be implemented in a laser driver assembly which includes a laser driver and a sampling loop configured to facilitate sampling of photodiode current produced by a monitor photodiode (MPD) of an optical transmitter assembly. The sampling loop comprises a low pass filter with reset, a digital-to-analog converter (DAC), and a comparator. The filter receives transmit (Tx) data provided to the laser driver and generates an output corresponding to a number of consecutive bits of a first type received in the transmit (Tx) data. The filter resets the output when a bit of a second type is received. The digital-to-analog converter (DAC) outputs a threshold signal. The comparator compares the output from the low pass filter and the threshold signal, and outputs a signal indicating when the photodiode current is to be sampled.

主权项

1. A laser driver assembly comprising:
a laser driver; and a sampling loop configured to facilitate sampling of photodiode current produced by a monitor photodiode (MPD) of an optical transmitter assembly, the sampling loop comprising: a low pass filter configured to receive transmit (Tx) data provided to the laser driver and to generate an attenuated output waveform corresponding to an input waveform defined by a number of consecutive bits of a first type received in the transmit (Tx) data, the low pass filter configured to reset the output waveform when a bit of a second type is received; a digital-to-analog converter (DAC) configured to output a threshold signal; and a comparator configured to compare the output waveform from the low pass filter and the threshold signal, and to output a signal indicating when the photodiode current is to be sampled.