CMOS externally modulated laser driver
AssigneeInphi Corporation
InventorsKarim Abdelhalim, Jorge Pernillo, Halil Cirit, Michael Le
Life of this patent
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Abstract
The present invention relates to telecommunication techniques and integrated circuit (IC) devices. In a specific embodiment, the present invention provides a laser deriver apparatus that includes a main DAC section and a mini DAC section. The main DAC section processes input signal received from a pre-driver array and generates an intermediate output signal. The mini DAC section provides a compensation signal to reduce distortion of the intermediate output signal. The intermediate output signal is coupled to output terminals through a cascode section and/or a T-coil section. There are other embodiments as well.
Claims20
A laser driver system comprising:
- one or more current sources;
- a first DAC section configured to convert n bits input signals to a first intermediate signal, the first DAC section comprising one or more thermal bits, the first DAC section being coupled to the one or more current sources;
- a distortion compensation section configured to generate a compensation signal based at least on the one or more thermal bits;
- a cascode section comprising one or more cascode amplifiers, the cascode section configured to generate a second intermediate signal based on the first intermediate signal and the compensation signal;
- a voltage supply;
- a plurality of T-coil elements, the supply voltage being coupled to the cascode section via the plurality of T-coil elements;
- and
- a pair of differential output terminals coupled to the cascode section, the differential output terminals configured to provide output signals based at least on the second intermediate signal.
An external modulated laser driver apparatus comprising:
- one or more current sources;
- a main DAC section configured to convert n bits input signals to a first intermediate signal, the main DAC section comprising one or more thermal bits, the main DAC section being coupled to the one or more current sources;
- a mini DAC section configured to generate a compensation signal based at least on the one or more thermal bits;
- a cascode section comprising one or more cascode amplifiers, the cascode section being configured to generate a second intermediate signal based on the first intermediate signal and the compensation signal;
- and
- a pair of differential output terminals coupled to the cascode section, the differential output terminals being configured to provide output signals based at least on the second intermediate signal.
An external modulated laser driver apparatus comprising:
- one or more current sources;
- a pre-driver array to provide n bits input signals;
- a main DAC section configured to convert the n bits input signals to a first intermediate signal, the main DAC section comprising one or more thermal bits, the main DAC section being coupled to the one or more current sources;
- a mini DAC section comprising m bits and configured to generate a compensation signal based at least on the one or more thermal bits;
- a cascode section comprising one or more cascode amplifiers, the cascode section configured to generate a second intermediate signal based on the first intermediate signal and the compensation signal;
- and
- a pair of differential output terminals coupled to the cascode section, the differential output terminals being configured to provide output signals based at least on the second intermediate signal.
Dependencies are inferred from the claim text.