A 10-Meter Active Optical Cable Utilizing POF With 4 × 10-Gb/s CMOS Transceiver Chipsets

Abstract

This paper presents a 10-m active optical cable (AOC) utilizing a graded-index plastic optical fiber (POF) for HDMI applications, where 4-channel 10-Gb/s/ch transceiver chipsets were implemented in 0.13-μm CMOS process and integrated upon a FR4 PC-board within pluggable connectors. Passive optical alignment comprising optical devices, optical subassembly, and POF was precisely located within the tolerance range of +/-10 μm, leading to successful mass-production. The transmitter (Tx) includes a VCSEL driver exploiting equalization and feedforward pre-emphasis to support 10-Gb/s data modulation. Also, a novel input data detector is proposed to turn on/off VCSEL diodes automatically for longer sustainability and lower power consumption. The receiver (Rx) employs a double-gain feedforward transimpedance amplifier followed by a selectable two-stage equalizer to choose either 6-Gb/s or 10-Gb/s operations, depending upon the specified HDMI applications. Also, a simple dc offset current cancellation and a novel monitor circuit are proposed for stable biasing and to keep tracking the average photocurrent of each photodiode. Measured results of Tx demonstrate 5.6-mA bias currents and 6.0-mAPP modulation currents, consuming 21.25 mA in maximum, whereas Rx provides 56.7-dBΩ transimpedance gain, 6-GHz bandwidth, and -10.4-dBm optical sensitivity for 10 -12 BER with 21.2 mA current consumption. The 10-meter POF AOC demonstrates wide and clean eye-diagrams up to 10 Gb/s, successfully showing 8-Mpixel 60-fps video data stream.