APRIL 8, 2009 -- Integrated circuit supplier Phyworks (search Lightwave for Phyworks) has launched a high-sensitivity transimpedance amplifier (TIA) that enables lower-cost PIN photodiodes in the receive path of customer premises GPON applications to replace costly avalanche photodiodes (APDs). The reduction in component cost combined with elimination of the high-voltage bias circuitry and lower yields associated with APDs is expected to help increase FTTX GPON deployment.
With an intrinsic input referred noise level of 85 nA, the PHY1096 TIA offers low noise performance at 2.5 Gbps and has been designed to meet GPON Class B+ requirements with sensitivity better than -30 dBm when using a PIN photodiode.
The device is based on a pure CMOS process that operates from a 3.3-V power supply. It integrates a 34-kΩ transimpedance low-noise, front-end amplifier; automatic gain control; and a highly stable output stage.
An output is also provided that can be used to implement a signal-strength monitor circuit. For ease of interfacing, this is designed to sink or source a current equal to the PIN photodiode current. The PHY1096 is available in die form for mounting on a header to create a receive optical subassembly (ROSA) when combined with optics and photodiode. Operating temperature range is -40° to +85°C.