Norio Ueno

Novel cell-AGC technique for burst-mode CMOS preamplifier with wide dynamic range and high sensitivity for ATM-PON system

We propose a novel cell-AGC technique for an ATM-cell based burst optical receiver on a 156 Mbps subscriber system. The cell-AGC controls transimpedance gain according to the burst cell power and enables reception of burst signals with low extinction ratio. In addition, to realize high sensitivity, we developed an amplifier that is stable under changes in ambient conditions and deviations of transistor characteristics on IC. By adopting these techniques in a CMOS preamplifier-IC, the detectable power difference between burst cells was enlarged to more than 30 dB, and the minimum sensitivity was improved to less than -39.3 dBm. These performances show our new IC fully satisfy high sensitivity specification of an ATM-PON system, and incorporating this IC in the system makes it more flexible and economical.

A Line Termination Circuit for Burst-Mode Digital Subscriber Loop Transmission

This paper describes a line termination circuit for burst-mode bidirectional digital subscriber loop transmission. It incorporates the most advanced LSI technology to obtain compactness, low cost, and high reliability. Two CMOS LSIs have been developed; one is a line termination LSI (LT) and another is a circuit termination LSI (CT). LT LSI adopts a novel RC active filter-type equalizer and decision feedback bridged tap equalizer suitable for incorporation in LSI and provides high performance. By using these LSIs, a line termination circuit realizes a reach of over 5 km at 88 kbit/s bidirectional digital transmission. This paper describes each LSI and shows total performance characteristics in detail.