4 March 2010


GigOptix launches linear TIA for 40G coherent receivers

GigOptix Inc of Palo Alto, CA, USA, which designs optical modulators, drivers and transimpedance amplifier (TIA) ICs based on III-V materials, has made available samples of its GX3122 dual-channel linear transimpedance amplifier (TIA) designed for use in next-generation 40Gb/s dense wavelength division multiplexing (DWDM) coherent optical receivers.

The GX3122 TIA consists of two balanced linear 10Gb/s TIA channels in a single die (in order to reduce system complexity and cost). The device forms the gain interface between the photodiodes and the analog-to-digital converters (ADC) and digital signal processor (DSP) in a coherent optical receiver, and it is designed to have the required large dynamic range and to handle the high AC and DC currents with a consistently low total harmonic distortion (THD) of less than 5%.

Other key features include:

  • linear gain over 20dB of dynamic range;
  • automatic or manual gain control options;
  • peak detection function;
  • low power consumption; and
  • receive strength signal indicator.

“The GX3122 further expands our TIA portfolio by providing a dedicated solution for the emerging 40G coherent market,” says Julie Tipton, VP of marketing. The GX3122 is form-factor compatible with GigOptix’s 100Gb/s DP-QPSK dual-channel TIA, so receivers designed using the firm’s 100G dual-channel linear TIA solution for 100G DP-QPSK can now be easily re-targeted to 40G DP-QPSK operation using the lower-cost GX3122. “Similarly, customers who implement a design with our GX3122 can now move more rapidly to a 100G receiver design using our 100G TIA solution,” she adds. “This is a big win for customers who are resourced constrained and are looking to leverage existing engineering designs into new markets.”

GigOptix says that 40G coherent systems are seen as being a significant segment in future 40G DWDM networks due to the format's capability for long-haul reach, its high tolerance to signal distortions, and its expected operating expenditure (OpEx) savings over other 40G formats.

See related item:

GigOptix gives update and outlook for 2010

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