A Wideband Digitally Controllable RFIC with Gain and Wavelength Tunability and Built-in Self Test Functionalities for Optical Transceiver Modules in FTTx Applications

This paper presents a wideband RF mixed-signal integrated circuit for optical transceiver modules in FTTx applications. The RF transceiver has an operating frequency range of 700 MHz to 2.5 GHz and a gain which is tunable to the range of 31.5 dB in 0.5 dB steps. Built-in self testing is incorporated with a 3-bit digital-controlled ring oscillator for testing the basic functionality of the circuit. Wavelength tunability for the optical transceiver module is realized by means of a digital-controlled current source which has a ± 60 mA output current range and a resolution of 1 mA. The RF and analog parts of the circuit operate on a 3.3 V supply, whereas the digital core has a 1.2 V supply voltage. The die occupies 5.07 mm² in area and the IC has a maximum power consumption of 674.74 mW.