A 156-Mb/s CMOS optical receiver for burst-mode transmission

In a point-to-multipoint fiber-optic subscriber system using TDMA (time division multiple access), the receiver should be able to handle burst-data packets with different amplitudes, Moreover, high-bit-rate operation is desired for multimedia communications. The operational speed is mainly restricted by the input parasitic capacitance of the preamplifier. Reducing the input impedance of the preamplifier widens its frequency bandwidth, and it makes high-speed operation possible. A multistaged preamplifier using feedforward phase compensation technique has been devised for small input impedance with stable operation at high frequency. Multistaged feedforward bias control is used for quick response to burst data, and the time constant is also reduced for high-speed operation. Using these design techniques, an optical receiver IC was fabricated using standard 0.5-/spl mu/m CMOS technology. The instantaneous response receiver has high sensitivity of -35.6 dBm, a wide dynamic range of more than 26 dB for burst-mode optical input at 156 Mb/s, and requires no external adjustment. The use of standard CMOS technology and the freedom from external adjustment make it possible to build an inexpensive receiver module.